FAQ
<THIS FAQ IS A WORK IN PROGRESS>
<Right now this is a stream-of-consciousness consolidation of the QTY1300+ comments on insightcentral.net>
<For now, reading the FAQ is faster than reading the threads on insightcentral.net>
<The FAQ will soon be sorted, edited, condensed, and spread out amongst several pages>
Q: How much lighter is an LiBCM-equipped pack?
A: A complete OEM NiMH pack weighs 73 pounds (including MCM & BCM).
A: A complete LiBCM-eqipped pack weighs 62 pounds (with MCM & grid charger).
Q: Can I convert an 18S+ pack to 18S- (or 18S- to 18S+)?
A: No. This concept never made it off the drawing table. While it is technically possible, Linsight does not support it, so you're on your own mechanically if you go that route. Linsight only supports the configurations shown here: linsight.org/kit.
Q: Is the LiDisplay included with the DIY LiBCM Kit?
A: The LiDisplay product has not been designed yet. For now, a basic 4x20 debug LCD is included. Once LiDisplay exists, it will be sold as a separate product (for maybe $100... TBD).
Q: Do you still recommend the mod to keep 12 volt battery charged (i.e. cutting WHT/GRN wire heading to DCDC) with LiBCM?
A: Yes, I always recommend cutting the WHT/GRN wire heading to the DCDC converter. IMO, the feature the WHT/GRN wire controls was a design mistake... Honda shouldn't have done it.
A: Cutting the WHT/GRN wire forces the DCDC to output 14.x volts, which keeps the 12 volt battery charged just like a traditional alternator does. Cutting the WHT/GRN wire still allows the MCM to disable the DCDC entirely (which is controlled by GRN/BLK).
A: Cutting the WHT/GRN wire is not required and technically has nothing to do with LiBCM... but you should cut it.
Q: Can LiBCM make the DCDC converter turn on whenever the key is in the 'ON' position (e.g. without first starting).
A: Yes. Details to be announced later. It will require routing the GRN/BLK wire from the DCDC converter to a GPIO pin on LiBCM. No, I don't have any other details yet. Yes, it will be cool.
Q: If LiBCM and/or the lithium modules fail, will my car still run?
A: In an error condition where LiBCM is at-fault, simply unplugging the BCM connector (as Peter suggests) will cause the IMA system to behave identically to the OEM system. If the LiBCM PCB itself is not damaged, it will continue monitoring the lithium battery voltages even when the BCM connector is unplugged. If a cell gets too high/low, a buzzer will sound (whether or not the vehicle is on). That's your indication to turn the master IMA switch off. If you keep driving the vehicle with the buzzer on (without turning off the IMA switch), the lithium modules could catch on fire. That's an extremely unlikely scenario. Overall, LiBCM won't leave you any more stranded than an OEM pack will.
Q: Will LiBCM work in my car is something in the IMA system is broken?
A: LiBCM will not work unless the IMA system is entirely present and functional, except that the OEM BCM and the actual NiMH cells can be in any condition (because LiBCM replaces them entirely). Everything else in the IMA system must work.
Q: Is it safe to touch the grid charger power cable's exposed male prongs when the 5-15P plug is not connected to a standard US outlet?
A: Yes. There are redundant diodic and galvanic isolation barriers between the IMA HVDC bus and the 5-15P plug.
Q: If you are using any other lithium module (e.g. Nissan Leaf, etc):
-I will send you BMS ribbon cables as long as you want.
-You alone are responsible for correctly connecting these cables to each cell.
-You must use a lithium chemistry whose charging range lies between 3.000 & 4.200 volts.
LTO & LiFePO4 modules ARE NOT ELIGIBLE for the early adopter program.
Q: Can I use LiBCM with the original NiMH cells?
A: From a technical standpoint: yes... you'd need to change the firmware. I will not help you do that.
A: I can't think of a reason why you'd want to do this.
Q: Can I use LiBCM without any battery at all (e.g. as a defeat device to pass emissions)?
A: From a technical standpoint: yes... you'd need change the firmware. I will not help you do that.
A: From a legal standpoint: per 42 USC 7522, defeating an emissions component is illegal in the United States.
A: Note that there are several cheap/free methods to defeat IMA-related P-codes in the G1 Honda Insight.
Q: Is LiBCM legal to use on roadways in the United States?
A: Yes, per the "Clean Alternative Fuel Vehicle and Engine Conversions Act", passed in 2011.
A: See 40 CFR parts 85 & 86.
Q: Which lithium chemistries will LiBCM work with?
A: LiBCM's hardware supports all known lithium cell chemistries.
A: The firmware defaults attempt to keep each cell between 3.25 volts (10% SoC) and 3.9 volts (85% SoC), with absolute max values between 3.00 volts (0% SoC) and 4.2 volts (100% SoC).
A: These values can be changed (at your own risk) to any value between 1.1 & 5.0 volts.
Q: How "open source" is LiBCM?
A: 100%. The entire design is located here: github.com/doppelhub/Honda_Insight_LiBCM
Q: Can I manufacture and sell my own LiBCM modules?
A: Yes, except that you cannot use the names 'LiBCM' or 'Linsight', which are trademarked.
A: Full disclosure: you probably won't make any money doing it.
Q: Does LiBCM work with other vehicles (besides the G1 Honda Insight)?
A: No.
Q: Can I make LiBCM work with other vehicles?
A: If you are technically competent, you can do whatever you want with LiBCM. LiBCM is entirely open source.
A: I'm not interested in 'porting' the design to other vehicles.
A: If you expect me to 'port' LiBCM for you, expect me to charge you an hourly rate.
Q: Do I really need a battery management system (BMS) to use lithium batteries? I've seen lithium conversions that don't use them.
A: Most lithium battery chemistries are unstable outside of a narrow voltage range. As a pack is charged/discharged, each cells' voltage can drift away
A: Operating a lithium battery without a BMS
Q: Why is LiBCM so expensive?
A: It's not.
A: As of this writing, I've personally invested more than 2200 hours designing LiBCM. I estimate that each LiBCM Kit will take 4 hours to manufacture. Assuming I sell QTY250 LiBCM units, I'll have invested 3200+ hours into the LiBCM project, which works out to 13 hours of labor per shipped LiBCM unit. Honestly I should charge quite a bit more for LiBCM, but it's a labor of love... I'm not in this for the money.
Q: How do I pronounce the name?
A: Layman's terms: Say the five letters separately (L, I, B, C, M)
A: Phonetic: El+Eye+Bee+Sea+'Em
A: IPA: 'ɛl'aɪˈbiˈsiˈɛm`
Q: What new features does LiBCM add?
A: More power! LiBCM can more than double the original hybrid power output.
A: Effortless grid charging comes standard. Plug LiBCM into an extension cord; LiBCM handles everything else.
A: Built-in cell balancing whenever the car is off.
A: Per-cell voltage measurements. Diagnose pack issues down to the specific cell.
A: Custom LCD screen reports real-time hybrid pack data to the driver.
A: Advanced USB diagnostic data. Log data to your computer as you drive.
A: USB firmware updates... add new features as they become available
A: LiBCM can cool the battery while the car is off.
Q: How can LiBCM "more than double the original hybrid power output"? Is that safe?
A: Insight's NiMH cells are the weakest link in the original hybrid electric design. LiBCM replaces the dated NiMH cell design with modern lithium cells, which can handle considerably more power. In fact, the 5 Ah lithium modules LiBCM is primarily designed for can safely source
Q: Does LiBCM work with CVT transmissions?
A: Yes.
Q: Does LiBCM work with 2005 & 2006 Honda Insights?
A: Yes.
Q: My IMA/CEL light is on. Will LiBCM 'fix' that?
A: If the IMA issue is due to a failing NiMH battery, then yes.
A: LiBCM will not 'correct' any other IMA/CEL error.
Q: How long will LiBCM's lithium battery last?
A: Panasonic's datasheet specifies their EHW5 cell will retain 80% of original capacity after 10 years.
A: The 5 Ah EHW5 Panasonic cell is rated for 50,000 cycles (10-85% SoC) with a continuous 40 A charge/discharge test.
Q: What are the best ways to maximize battery life?
A: In warm weather, park Insight out of direct sunlight.
A: When temperatures drop below freezing for extended periods, park Insight in direct sunlight (to increase pack temperature during the day).
A: Grid charge the battery whenever the cell voltage delta exceeds 25 mV (LiBCM balances the cells while grid charging).
Q: What is LiBCM's recommended ambient operating temperature range?
A: -30 degC to 55 degC
Q: What safety features does LiBCM use to prevent electrocution?
A: Safety is LiBCM's primary goal.
A: Once the safety cover is installed.
A: Retains OEM safety features
Q: What happens if my Insight is in a wreck?
A:
Q: Is LiBCM better than the original hybrid computer?
A: Absolutely, and in every way.
A: LiBCM replaces Honda's poorly designed "Battery Condition Module" ('BCM'), How many times have you replaced your NiMH battery over the past 20 years?
A: Modern lithium batteries consume less power internally (under load). Less wasted energy in the pack equals more energy delivered to the wheels.
Q: What is a "Drop-In LiBCM Battery"?
A: The system I recommend you buy.
A: A completely assembled lithium battery - contained within the original plastic battery housing - with the LiBCM computer already connected and ready to go.
Q: Where do I purchase a Drop-In LiBCM Battery?
A: BumbleBatteries.com is the primary Drop-In LiBCM Battery distributor.
A: The following insightcentral.net members are authorized to install
A: I do not sell Drop-In LiBCM Batteries directly to customers. However, I do offer an "LiBCM Kit" for sale to anyone who can pass my safety quiz.
Q: How often should I grid charge?
A: Grid charging is only necessary when the resting cell voltages become severely unbalanced. However, I recommend grid charging as often as possible. Starting each trip with a full pack allows you to use assist without worrying about the mpg penalty required to recharge the pack.
A: With LiBCM, there's no 'guesswork'... LiBCM's LCD display will tell you when grid charging is necessary.
Q: Can I leave the grid charger plugged in?
A: Yes, for as long (or as little) as you'd like. LiBCM 100% handles grid charging, just like any other modern lithium vehicle.
Q: Why is LiBCM better than the original?
Q: How hard is LiBCM to install?
Q: What vehicles does LiBCM work with?
A: LiBCM is designed specifically for the G1 Honda Insight (2000-2006).
Q: How many cells in series does LiBCM support?
Q: Will LiBCM make my car faster?
A: Absolutely. The difference is night-and-day. Once you drive an LiBCM-equipped Insight, you'll never want to switch back.
Q: How do I grid charge LiBCM?
A: With the key off, plug LiBCM's NEMA 5-15P power cable into an extension cord.
Q: How often do I need to grid charge?
A: I recommend grid charging whenever possible, so that the battery is charged at the beginning of each drive cycle.
Q: Is LiBCM open source?
A: Absolutely 100%. You can view the entire design here:
github.com/doppelhub/Honda_Insight_LiBCM
Q: What's included with the "LiBCM Kit"?
A: Short answer: everything except the actual lithium battery modules.
A: LiBCM Kits include:
-QTY1 LiBCM PCB, with clear safety cover
-QTY3 aluminum end plates, to secure each battery module to the OEM enclosure
-QTY6 high current cables
-QTY2 low current cables
-QTY1 grid charger, with harness
-QTY1 2.5 mm hex wrench
-QTY3 BMS sense lead adapters
-QTY4 8" zip ties
-QTY2 wire nuts
-QTY1 4x20 character LCD screen, with cable
Q: What additional items are needed to use an LiBCM Kit with my Honda Insight?
A: Lithium battery modules.
Q: Where do I get lithium battery modules?
A: LiBCM is primarily intended for use with Panasonic EHW5 modules, which are (probably) used in the following vehicles (I have not personally verified this):
-2019+ Honda Insight (Honda part number 1D070-6L2-A00)
-2018-2020 Accord Hybrid (Honda part number 1D070-6C2-305)
Q: What is LiBCM's warranty period?
A: "Drop-In LiBCM Batteries" are warranted per the terms of the authorized reseller.
A: From a legal standpoint, "LiBCM Kits" are provided as-is, without any warranty whatsoever. Note that each Each LiBCM Kit is 100% test driven prior to shipment. However, I will make reasonable efforts to repair defective components at my actual cost, regardless of fault. If the LiBCM PCB cannot be safely repaired, I will replace the entire PCB at a reduced cost.
A: On a case-by-case basis, if I determine the failure occurred at no fault of the user, I will repair the PCB for free, excluding shipping costs.
Q:
Q: What tools are required to install an LiBCM Kit into ?
A: Installing an LiBCM Kit into the OEM battery housing requires:
-1.25" hole saw
-5/32" drill
-_____ drill (low current HVDC cables)
-#2 Phillips driver
-#3 Phillips driver
-2.5 mm width flat blade driver
-2.5 mm hex wrench
-
Q: Where is LiBCM manufactured?
A: In my garage in Chattanooga, TN, using globally sourced parts.
A: Here's a video: https://www.youtube.com/watch?v=lkyL85lTiGc
Q: What portions of the original hybrid system does LiBCM replace?
A: LiBCM replaces the two weakest links in Honda's original hybrid design:
-The original "Battery Condition Module" ('BCM'), which is poorly designed and notoriously bad at preserving pack health.
-The NiMH cells, and all assosiated cables that physically contact the cells.
Q: What portions of the original hybrid system are retained?
A: Everything else:
-The electric motor (inside the engine)
-The high current harness that connects the engine to the hybrid bay
-The high-power motor driver unit
-The DCDC converter
-The hybrid MDM computer, which works in tandem with LiBCM.
-All cabling and connectors between the various hybrid subsystems, except that a single wire must be cut (and then manually rewired into the LiBCM circuit board).
Q: Will LiBCM work with my _____ lithium battery?
A: Yes, as long as the total number of cells in series is QTY60 or fewer.
Q: Will LiBCM make my car heavier?
A: A Drop-In LiBCM Battery is <n> pounds lighter than the original NiMH system it replaces.
A: Larger lithium batteries will
Q: What aftermarket accessories are compatible with LiBCM?
A: Any accessory whose wiring doesn't physically connect to wires inside the IMA bay.
A: Any accessory that modifies the signals between the MCM & ECM (e.g. IMAC&C).
A: So-called "current hacks", except that LiBCM can spoof the battery current sensor in software. If you'd rather leave the entire 'current hack' in place, you can disable said software spoofing (and use your existing hardware instead). LiBCM is specifically designed for use with the (excellent) "Current Hack PCB", designed by @retepsnikrep & @Bull Dog.
Q: What aftermarket accessories are NOT compatible with LiBCM?
A: Any and all NiMH-based grid chargers, which are dangerous to use with LiBCM. LiBCM's built-in grid charger makes these unnecessary.
A: Dischargers of any kind. LiBCM's built-in balancing hardware makes these unnecessary.
A: Any device that intercepts/modifies data from the BATTSCI data bus (which routes from the BCM to the MCM).
Q: If I decide the LiBCM Kit isn't for me, can I get a refund?
A: Yes, and you don't need to state a reason. I will refund your entire purchase price - minus my actual costs** - for any reason whatsoever.
A: Note that I do not sell Drop-In LiBCM Batteries directly to end users (only LiBCM Kits). Therefore, if you purchase a Drop-In LiBCM Battery from an authorized installer and decide it isn't for you, then you'll need to contact the installer directly (and go by their terms).
**I will not refund the following fees:
-Actual shipping costs, and/or;
-Fees that PayPal doesn't refund. If you paid using "friends & family", then that fee is $0.30. If you paid using "commercial service", then that fee is $35.17, and/or;
-LiBCM Kit parts that are returned damaged; I will charge a reasonable fee to cover the repair.
Q: If I convert a car to use LiBCM - and then later decide to go back to NiMH - how easy is it to convert back to the original NiMH configuration?
A: If you follow the LiBCM installation instructions, the entire process is electrically reversible. Mechanically, there will be a few leftover holes, but they do not affect the original NiMH functionality.
A: Since LiBCM only modifies components within the original battery enclosure, the simplest method to convert back to NiMH is to purchase an additional NiMH battery enclosure.
A: If there's any chance you might want to revert back to NiMH later, watch this video prior to converting to LiBCM for key points to look out for when performing the conversion modifications.
Q: Why doesn't LiBCM support ____________?
A: Maybe it should? I'm all ears for any and all feature requests.
A: Before submitting a feature request, please check <here> to make sure I haven't already added the feature to my "todo" list, or placed it on my "never going to happen" list.
Q: How long can I leave my LiBCM-equipped Insight parked without charging (e.g. at the airport)?
A: This primarily depends on the initial SoC and the ambient temperature. But in general:
-Best case (mild temperature and 100% initial SoC): 3 years
-Worst case (extreme temperatures and 10% initial SoC): 3 months
Q: If I plan to park my Insight for longer than the above figures, how do I prevent LiBCM from completely discharging my battery to empty?
A: Grid charge the battery until full, or;
A: Leave the grid charger plugged in as long as the car is in storage, or;
A: Turn the IMA master switch off (ideally with the pack half-charged).
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Shipping:
Q: Do you
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Safety:
Q: Is the LiBCM Kit dangerous to install?
A: Absolutely. LiBCM can easily kill you if you don't follow the installation instructions.
Q: Does LiBCM support lithium packs larger than 48S?
A: The hardware supports up to 60S packs.
A: The firmware only presently supports 48s
A: FYI: The OEM HVDCDC converter shuts down immediately above 220 volts.
A: If using EHW5 modules in the OEM battery enclosure, an 18S module will not fit in the bay closest to the junction board (bay 1), unless you design different high current cables and route them externally.
Q: Will LiBCM work with packs larger than 60S?
A: Not easily. You would need to connect an additional BMS PCB to LiBCM's SPI bus, and then rewrite the firmware to talk to it. It's possible, but you're on your own.
Q: Will LIBCM work with packs less than 36S?
A: Probably not, as the pack voltage becomes too low; the OEM MCM prevents assist below 110 volts.
A: If the voltage drops too low, the MCM will enable force background charging, which could overcharge packs less than 36S.
Q: What is "Linsight"?
A: Linsight is a company.
A: Short for "lithium insight"
A: Previously the name of a never-released hardware project. That project morphed into "LiBCM". "Linsight" morphed into the company name.
Q: What is "LiBCM"
A: Lithium Battery Condition Monitor
A: The name of the first product sold by Linsight.
A: A drop-in replacement computer that allows safe lithium operation in the G1 Honda Insight (2000-2006).
Q: What parts of the original IMA system are not reused by LiBCM?
A: See this video: https://www.youtube.com/watch?v=5RkxeL5m9-A
Q: What parts of the original IMA system are modified by LiBCM?
A: The IMA wire harness has a single wire cut and spliced. Easily revertible.
A: The battery temperature harness has two wires cut and shortened. Easily revertible.
A: The battery voltage tap harness (with orange side plate) has two wires cut. Easily revertible as long as you only cut those two wires (more details in installation videos).
Q: How much additional power does LiBCM add to the car?
A: A stock IMA system with NiMH cells delivers at most 12 kW (16 horsepower).
A: An LiBCM-equipped pack in a manual transmission car delivers at most 18 kW (24 horsepower)(50% more power)
A: Adding the current hack PCB (https://www.youtube.com/watch?v=wtwM0kgxeJ4) to a manual transmission car increases LiBCM power to at most 24 kW (32 horsepower)(94% more power).
A: Adding the current hack PCB to a CVT car increases LiBCM power to around 21 kW.
A: The above values are only briefly possible in 2nd or 3rd gear. To access this power at your command, you need a manual IMA control system.
A: LiBCM can theoretically deliver at most 32 kW (42 horsepower)(e.g. with lower ESR cells and 60S configuration).
A: Watch this video: https://www.youtube.com/watch?v=srkx_Rq2-ro
Q: Will all this additional power 'hurt' the stock IMA system?
A: The NiMH pack is by far the weakest part of the OEM IMA system.
A: The next weakest part is the IGBT module. The MCM monitors both current and temperature on this module (and will disable assist/regen as needed).
A: The IMA motor does not have temperature feedback. However, the 5 Ah EHW5 lithium modules LiBCM is designed for cannot provide regen/assist long enough to overheat the motor (a larger lithium battery could, though). Anecdotal evidence suggests that discharging an 8x larger pack does not overheat the IMA motor.
A: Overall, there's low risk that installing LiBCM will damage the IMA system.
A: LiBCM could cause increased wear on mechanical components, due to the increased torque delivered to the wheels.
A: Use LiBCM at your own risk.
Q: Why does LiBCM spoof a lower pack voltage? Why not send the actual voltage to the other car computers?
A: The lithium charge/discharge voltage curve is substantially different from NiMH cells.
A: Sending the actual pack voltage would cause the IMA system to undercharge the lithium modules.
A: Spoofing a lower voltage causes the IMA system to deliver more power to the hybrid motor.
Q: Can LiBCM communicate directly with the H-Line serial bus
A: The LiBCM hardware supports it, but it's not supported in firmware.
A: The OEM BCM isn't connected to the H-line either. Instead, the MCM transmits BCM data to the H-line (e.g. to display SoC on OBDIIC&C).
Q: Does LiBCM ever turn off?
A: Not unless it needs to (e.g. because the battery is empty). Leaving LiBCM on has the following benefits:
-always detect when grid charger is plugged in.
-cool pack if too warm.
-cell balancing (which only occurs in key OFF state).
FYI: Turning the IMA switch off turns LiBCM off.
Q: Safety
A: The entire HVDC bus is galvanically isolated from the control circuitry. There is ZERO risk that high voltage from the HVDC bus finds its way into the digital control circuitry.
There's no danger with any low voltage signals coming from LiBCM. They're all completely galvanically isolated. The entire LiBCM PCB can burn to a crisp and there's zero chance the HVDC will bridge to the low voltage control signals.
A: -Neither HVDC line connects to chassis ground. Therefore:
--if one line touches the chassis, there's zero electrocution risk, unless you then touch both chassis ground AND the other HVDC cable (which is exceedingly unlikely to occur, because that would mean you got in a crash, and then for some reason stuck your hand into the IMA bay).
--If both lines touch chassis ground, then that will blow out the main fuse. Zero electrocution risk, even if you're touching chassis ground.
--The MCM constantly monitors for HVDC faults to chassis ground. If a ground fault is detected, the MCM will open the HVDC contactor.
Q: Why would placing the fuse/switch between modules 2 & 3 damage LiBCM?
A: Six cells in each of these two modules share a single LTC6804 voltage monitoring IC. If the fuse blows and/or the switch is turned off - and then current is applied to the HVDC bus - then the full pack voltage will develop across one LTC6804. This will (safely) destroy the LiBCM PCB. The ideal solution is to use a different BMS IC (e.g. LTC6813), but the Great Chip Shortage forced my hand.
Q: How long does it take to balance a lithium pack?
A: Healthy lithium packs generally stay well balanced, and spend at most a few hours balancing each month.
A: An unhealthy pack will still rebalance completely overnight.
A: When LiBCM is first installed in the car, if the SoC is drastically different between two modules, then it could take several days to balance the cells. It's ok to drive the car with an unbalanced pack, but the SoC range will be limited.
FYI: Balancing occurs automatically whenever the car is off, as long as the pack SoC is above 30%.
Q: Why does it take so long to balance the lithium cells?
A: LiBCM balances cells by connecting a 75 Ohm resistor in parallel to each 'full' cell. LiBCM balances cells near 3.9 volts, hence LiBCM can only discharge full cells at 52 mA (200 mW/cell). Since each 5 Ah EHW5 cell contains 18.5 Wh of energy, if you were to install one completely empty module (0% SoC) and another completely full module (100% SoC), then the worst-case balancing time would be 92 hours.
A: After the initial balancing concludes, the cells in a healthy pack should always stay well balanced.
Q: If my car previously had the current hack installed, do I leave it installed?
A: The only current hack hardware that should be installed with LiBCM is the single PCB inside the MCM (https://www.youtube.com/watch?v=wtwM0kgxeJ4). Remove all other current hack hardware.
Q: Why is the grid charger so slow?
A: Cost. LiBCM is designed to fully charge a completely discharged EHW5 pack overnight.
A: LiBCM supports higher current grid chargers, as long as the following conditions are met:
-If the grid charger sources more than 3 amps from the wall outlet, then you need to replace both tube fuses on LiBCM with a higher-current-rated variant.
-The grid charger must source and sink less than 8 amps (with larger fuses installed).
-The grid charger must be connected to LiBCM identically to the included grid charger.
A: Replacement grid chargers must meet the following criteria:
-constant current supply
-must output voltage between at least 139:207 volts (with 48S lithium cells)
-output current must be controllable via a PWM pulse train.
A: Example replacement grid charges:
-HLG-480H-C2100B (charges 5 Ah pack empty-to-full in under two hours)
-HLG-320H-C1400B (charges 5 Ah pack empty-to-full in under three hours)
-PLED200W-190-C1050-D (charges 5 Ah pack empty-to-full in under four hours)
-GEN200-16.5 (charger 5 Ah pack empty-to-full is under fifteen minutes)
Q: How do I use the grid charger?
A: Turn the car off, then plug the power cable into any standard wall outlet.
A: LiBCM's LCD display will display the state-of-charge, cell voltage, and temperature whenever the grid charger is plugged in.
A: Leave the charger plugged as long as you want. LiBCM handles all the logic, just like your laptop or cell phone.
A: Unplug the grid charger whenever you want.
A: LiBCM's onboard fans automatically activate as needed to heat or cool the IMA battery.
A: LiBCM won't drain your 12 volt battery.
Q: How often do I need to grid charge?
A: If the car is used regularly, then never.
A: See 'Q___' for recommendations for long-term storage.
A: Linsight recommends grid charging when possible to improve fuel economy.
Q: How does LiBCM calculate battery state-of-charge?
A: When the car is on, LiBCM integrates the measured pack current.
A: When the car is off, LiBCM estimates SoC based on the resting cell voltage. This removes any error accumulated during integration. FYI: SoC uncertainty is less than 1% per hour the car is on (e.g. after driving the car continuously for 5 hours, the SoC could be off by 5%. Each keyOff event resets the uncertainty to 0%.
A: You can manually set SoC to any value (via USB interface). However, LiBCM will automatically adjust SoC based on its own internal knowledge of the battery. For example, if you set the battery size to 1000 mAh, but the battery is actually 5000 mAh, then LiBCM will automatically adjust the correct value. In that sense, any value you manually enter is just a guideline for LiBCM to start from.
Q: Does LiBCM work with MIMA setups?
A: Yes.
Q: I want to use a different battery. Can I purchase just the LiBCM PCB (no cables/adapters/grid charger/hardware/etc)?
A: Yes, but only on a case-by-case basis. Please contact Linsight for more details.
Q: How much heat does the lithium pack generate internally (due to ESR)?
A; Around ten times less than the OEM NiMH pack. EHW5 lithium cells have an initial cell ESR around 1.1 mOhm.
A: Worst case calculation (full assist with current hack installed): Discharging at full power will generate 24 watts of heat per cell; a 48S pack will therefore internally generate 1200 of heat under full load. However, the IMA system will not deliver peak power for more than a few seconds, after which the power is greatly reduced.
A: LiBCM can continuously deliver 12 kW until the pack is empty. At this power level, each cell generates 8 watts of heat (worst case); a 48S pack will therefore generate 400 watts of heat worst case. Each EHW5 is therefore generating about the same heat as a 100 watt incandescent light bulb.
A: In practice, the self-heat generated inside the battery during assist/regen is inconsequential. The overwhelming contributor to pack heat is the cabin air temperature.
FYI: LiBCM directly monitors the temperature on each EHW5 module's outer steel enclosure. LiBCM also monitors the cabin air temperature, the exhaust air temperature, the IMA bay temperature, and several other temperatures to verify the pack operates within acceptable temperatures. LiBCM will disable assist/regen if needed to prevent self-heating.
Q: What other lithium chemistries are supported?
A: With firmware modifications, LiBCM supports all known lithium chemistries. Specifically, LiBCM supports any cell that charges with a CC/CV profile.
A: Without firmware modifications, LiBCM supports any lithium chemistry that can safely operate between 3.0 and 4.2 volts.
A: Without firmware modifications, LiBCM supports batteries from 1 Ah to 65.5 Ah.
A: While LiBCM supports most lithium batteries, Linsight only officially supports EHW5 lithium modules.
Q: Does LiBCM work in any other vehicles besides the G1 Honda Insight (2000-2006)?
A: No.
A: LiBCM is a passion project.
A: With minimal effort (mostly mechanical fitment), LiBCM will probably work in the G1 Honda Civic Hybrid.
A: With dedicated engineering effort, LiBCM could probably work with most NiMH-based hybrid vehicles.
A: I'm not interested in adapting LiBCM to your vehicle.
Q: What certifications does LiBCM have?
A: None
A: LiBCM is exempt from FCC emissions testing requirements, per 15.103(A), which exempts "digital devices utilized exclusively in any transportation vehicle".
A: LiBCM is exempt from emissions _________
Q: Why can't I upload firmware onto the Arduino Mega PCB when it's disconnected from the LiBCM PCB?
A: Why did you do that? Put it back together!
A: The Arduino PCB connected to LiBCM has a custom bootloader that prevents host-initiated hardware resets unless both PCBs are mated together.
FYI: The custom bootloader allows LiBCM to boot in just 16.1 ms (the stock bootloader takes 920 ms). Faster booting prevents P1648-related errors (when LiBCM was initially off and the key turns on).
Q: Why does LiBCM have an Arduino Mega PCB on it?
A: LiBCM's production volume is so low that generic Arduino Megas are actually cheaper than just the cost of the MEGA2560 processor. The Mega also includes two MCUs, a USB port, an oscillator, a voltage reference.
A: It's in stock. I've had zero issues buying them, which is more than I can say for pretty much any other part right now.
A: V&V is easier when I can remove the MCU as needed to troubleshoot signals... pulling off the entire MCU allows me to inject signals anywhere I want, without having to worry about how the MCU will behave.
A: Mechanical issues would have required a separate PCB for the USB connector anyway.
A: USB firmware updates are easy thanks to Arduino team's dedicated bootloader legwork. This is good for customers.
A: People unfamiliar with embedded development environments can modify the firmware without having to install a complete embedded toolchain (e.g. IAR/Atmel Studio/etc). Arduino is hands down the easiest embedded toolchain out there.
A: LiBCM is nearly feature complete and yet is only using 10% of CPU time, 7% of storage, and 22% of RAM... with an 8b MCU.
Q: When should I plug in the grid charger?
A: Whenever you want, as long as the key is off.
A: When the IMA SoC is below 30%, LiBCM will turn itself off ten minutes after the keyOff event. Therefore, if SoC is below 30%, then the grid charger will not charge unless it's plugged in within ten minutes of turning the key off.
A: To prevent driving off while the grid charger is plugged in, LiBCM does not allow grid charging when the key is on. If the grid charger is connected and the ke is on, LiBCM will:
-emit a continuous audible beep
-display a warning message on the LCD
-set a Pcode and disable IMA-starting.
Q: What's special about cell 24?
A: Cell 24's Vsense circuit is unique in that it is mechanically in the middle of an 18S lithium module, but electrically C24+ (also C25-) is shared between two different LTC6804 ICs (each IC measures QTY12 cells).
Q: What benefits does LiBCM offer?
A: if/when a specific cell does eventually fail, LiBCM will tell you exactly which cell has failed. You can then replace that single cell (or even just short it out). Note that you'll even be able to mix-and-match cells... LiBCM will obviously be limited by the weakest cell, but given the BMS circuitry, LiBCM will be able to 'correct' for weakness on a per-cell basis.
A: increased battery lifetime, cell-level troubleshooting, and lower ESR.
Q: What happens ten years down the road when these EHW5 modules die?
A: Fortunately, these lithium cells seem destined to become a de-facto standard... and if not, then a decade from now we can always have more made specifically for our purpose. Or maybe another existing lithium pack design will come along that's equally compatible.
Q: Do an EHW5 lithium battery store more energy than the stock NiMH pack?
A: A 48S LiBCM-equipped IMA battery with EHW5 lithium cells stores 30% more deliverable energy than an OEM NiMH pack*.
*An OEM NiMH pack nominally stores 936 Wh, whereas the EHW5 lithium pack only stores 887 Wh. However, the lithium pack has a wider safe operating SoC range, and can therefore deliver more energy (666 Wh) than the OEM pack (515 Wh).
Q: What are the two DIP switches on the LiBCM PCB used for?
A: "Disable Reset" = ON: plugging in the USB cable does not restart LiBCM, but USB firmware updates are not allowed
A: "Disable Reset" = OFF: plugging in the USB cable restarts LiBCM, and USB firmware updates are allowed (default)
A: "User Switch" is firmware-programmable behavior. Not presently implemented for any specific task.
Q: Why Arduino?
A: Easiest programming environment for a new user to get started in. I'm definitely thinking about the end-user when it comes to customization.
A: LiBCM is mostly written in pure C. A few HAL-specific tasks use the (slower) Arduino language.
A: The Arduino IDE is mostly used for the built-in GCC compiler, plus point-and-click interface.
Q: 54S: Considering the abundance of 18S modules, and that a 54S setup would fit just as well in the stock enclosure as a 48S, what additional difficulty would be involved in setting up LiBCM as a 54S configuration?
A: While QTY3 18S modules mechanically fit inside the OEM enclosure, placing an 18S module in bay 1 (closest to the junction board) prevents the high current cables from cleanly routing to the junction board. You would need to figure out how to externally route the current cables to the junction board.
A: There are many firmware changes required to use a 54S pack (MCM'E' voltage, ,,,etc).
Q: How do I update the firmware?
A: (Beta) Watch this video:
A: Make sure the car is off (or you'll get a CEL).
A: The IMA switch can either be off or on (doesn't matter).
Q: I found a problem with the firmware/hardware/LiBCM. How do I submit a bug request?
A: https://github.com/doppelhub/Honda_Insight_LiBCM/issues
OR
A: <Link to LiBCM Issues/Bugs/Requests Page>
Q: What voltages does LiBCM 'spoof' to increase power?
A: BATTSCI (digital)
A: MCM'E' (high voltage, modified with galvanically isolated PWM train)
A: VPIN (LiBCM man-in-the-middles this analog signal). This is the orange wire that is modified on the IMA wire harness.
A: Full explanation: https://www.youtube.com/watch?v=5rsAQy2ybBA
Q: What additional parts do I need to install the current hack?
A: A 150 amp, 175 amp, or 200 amp L50S Littelfuse
A: @Bull Dog's MCM Current Hack PCB (link:_________)
A: Install video: https://www.youtube.com/watch?v=FATCvhCUAjk
Q: Do I need to install a larger fuse to use LiBCM?
A: Only if you also add the +40% Current Hack PCB (inside the MCM)
Q: Should I install the current hack PCB?
A: Yes
A: Your friends will stop telling you your car is slow.
A: There aren't any downsides.
A: If you decide it's not for you, disabling the hack is as simple as toggling four DIP switches and uploading new firmware to LiBCM.
Q: Does LiBCM safely manage cell voltage under all conditions?
A:
Q: Will LiBCM improve my mileage?
A: If your old pack is toast, then yes.
A: Otherwise, it entirely depends on driving habits.
A: My mpg hasn't changed, but I drive the car much faster/harder now.
A: (Beta) the default voltage spoofing algorithm isn't yet optimized for fuel efficiency.
A: LiBCM supports several different charge profiles. For example, if you always drive short distances and grid charge when parked, you can tell LiBCM to limit/disable regen. See config.h for more info.
Q: Why do I sometimes get IMA error code P1648 while driving?
A: P1648 means LiBCM isn't sending data to the MCM.
A: If the P1648 error occurs infrequently, then it's probably an RF noise issue. A beta tester noted that moving the LCD cable further away from the main wire harness near the parking brake reduced the error rate. The production LCD cables are shielded, and there's more signal conditioning on the conductors. Production LiBCM units probably won't see this P1648 errors caused by RF interference.
A: If the P1648 error occurs immediately and persists across several drive cycles, then LiBCM isn't powered, or the firmware isn't running. Troubleshooting steps:
-Verify the IMA switch is on.
-Turn the IMA switch off and then on.
-Verify at least one green LED near the USB connector is on; if not, then check the user-replaceble fuses.
-Update the firmware
Q: Why do I sometimes get P1576(12) while driving?
A: This is a voltage mismatch between two voltages LiBCM sends to the MCM (MCM'E' & VPIN). To fix ______________________
it's probably P1576(12), which suggests that your car's MCM is sampling VPIN differently than my car... or maybe we're just both on an edge case and your car is more likely to throw this issue. On your end, I recommend measuring VPIN_in and VPIN_out with a DMM while in autostop. Multiply your DMM measurements by 52 and that should be within 10 volts of the actual and spoofed pack voltage (as reported by LiBCM). Example measurements (that I just made up):
-VPIN_in (to PDU) measures 3.475 volts
-pack actual voltage (as measured by LiBCM) is 180.6 volts
3.475 * 52 = 180.7 volts, which is within 10.0 volts of 180.6 volts, so all is good.
-VPIN_out (to MCM) measures 3.123 volts
-pack spoofed voltage (LiBCM sends this value to MCM via BATTSCI) is 160 volts
3.123 volts * 52 = 162.4 volts, which is within 10.0 volts of 180.6 volts, so all is good.
P1576(12) occurs when the MCM'E' voltage disagrees with the VPIN voltage by more than 10 volts for more than two seconds.
About once per second, the MCM's "Insulation Resistance Check" (IRC) routine injects a test current - sourced from chassis ground - alternatively into the MCM'E' connector's HVDC+ & HVDC- leads.
In the OEM configuration, the MCM'E' connector has a low resistance path back to the battery (less than a couple ohms). However, on LiBCM the return path is substantially higher (around 20 kOhm, see R69/R70/R71/R72/R335/R336). This high resistance is required to spoof the MCM'E' pack voltage. Therefore, when LiBCM is installed, the MCM'E' voltage droops whenever the IRC test is active (about once per second).
When the IRC test finishes, the current injection is disabled, which causes the MCM'E' voltage to slowly rise back to the actual pack voltage. Specifically, the voltage rises with a 1st order LPF, where R = 20 kOhm & C = 118 nF (Tau = 2.4 ms).
A (constant) short time later, the MCM measures the MCM'E' HVDC voltage with a high impedance ADC. However, due to the large time constant, the MCM'E' capacitors are still charging, hence the voltage the MCM's ADC measures on MCM'E' is less than the actual pack voltage. In both my cars, the MCM'E' voltage offset is a constant value: 12 volts less than the actual pack voltage. Therefore, LiBCM adjusts the VPIN voltage and BATTSCI voltage values by 12 volts.
However, in those cars where the HVDC insulation resistance is too low - but not low enough to set a P-code (~300 kOhm) - this constant offset voltage value will increase (e.g. to 23 volts, etc). Note that as long as the insulation resistance exceeds some value (TBD, e.g. 1 MOhm), the offset should remain constant (e.g. specifically 12 Ohms). The offset will only change when the insulation resistance drops below some value (TBD, e.g. 500 kOhm).
The solution is probably going to be to add a voltage offset constant into the config.h file:
#define MCME_VOLTAGE_OFFSET_ADJUST 0 //difference between OBDIIC&C and LiBCM spoofed pack voltage
This will only work if the HVDC leakage is fairly constant, possibly by comparing LiBCM's spoofed pack voltage (on 4x20 screen) to the OBDIIC&C's measured pack voltage. For example, if LiBCM's spoofed voltage is 168 volts, whereas OBDIIC&C displays 142 volts, then we would set
MCME_VOLTAGE_OFFSET_ADJUST = (168-142) = 26
P1576(12) occurs when the MCM'E' voltage disagrees with the VPIN voltage by more than 10 volts for more than two seconds.
About once per second, the MCM's "Insulation Resistance Check" (IRC) routine injects a test current - sourced from chassis ground - alternatively into the MCM'E' connector's HVDC+ & HVDC- leads.
In the OEM configuration, the MCM'E' connector has a low resistance path back to the battery (less than a couple ohms). However, on LiBCM the return path is substantially higher (around 20 kOhm, see R69/R70/R71/R72/R335/R336). This high resistance is required to spoof the MCM'E' pack voltage. Therefore, when LiBCM is installed, the MCM'E' voltage droops whenever the IRC test is active (about once per second).
When the IRC test finishes, the current injection is disabled, which causes the MCM'E' voltage to slowly rise back to the actual pack voltage. Specifically, the voltage rises with a 1st order LPF, where R = 20 kOhm & C = 118 nF (Tau = 2.4 ms).
A (constant) short time later, the MCM measures the MCM'E' HVDC voltage with a high impedance ADC. However, due to the large time constant, the MCM'E' capacitors are still charging, hence the voltage the MCM's ADC measures on MCM'E' is less than the actual pack voltage. In both my cars, the MCM'E' voltage offset is a constant value: 12 volts less than the actual pack voltage. Therefore, LiBCM adjusts the VPIN voltage and BATTSCI voltage values by 12 volts.
However, in those cars where the HVDC insulation resistance is too low - but not low enough to set a P-code (~300 kOhm) - this constant offset voltage value will increase (e.g. to 23 volts, etc). Note that as long as the insulation resistance exceeds some value (TBD, e.g. 1 MOhm), the offset should remain constant (e.g. specifically 12 Ohms). The offset will only change when the insulation resistance drops below some value (TBD, e.g. 500 kOhm).
The solution is probably going to be to add a voltage offset constant into the config.h file:
#define MCME_VOLTAGE_OFFSET_ADJUST 0 //difference between OBDIIC&C and LiBCM spoofed pack voltage
This will only work if the HVDC leakage is fairly constant, possibly by comparing LiBCM's spoofed pack voltage (on 4x20 screen) to the OBDIIC&C's measured pack voltage. For example, if LiBCM's spoofed voltage is 168 volts, whereas OBDIIC&C displays 142 volts, then we would set
MCME_VOLTAGE_OFFSET_ADJUST = (168-142) = 26
Q: Why is the 4x20 LCD going away after the Open Beta period ends?
A: LiDisplay will entirely replace the existing screen. LiDisplay is a touch screen user interface with a 480*320 color display. It'll be a huge upgrade.
A: The 4x20 screen's serial architecture is terrible, antiquated, and has odd timing requirements. LiBCM spends more CPU time servicing the LCD screen than all other CPU tasks combined.
A: The 4x20 screen has a low-level driver bug that causes the CPU to lock up under certain hardware corner cases. I could write my own driver, but I've worked around the issue enough for now, and would rather focus that energy on the LiDisplay replacement.
A: LiBCM might be able to drive both displays simultaneously. If so, I'll deprecate the 4x20 display. If not, I'll write some code to auto-detect which display is connected; if LiBCM sees both displays, it'll use LiDisplay.
Q: If I decide to remove LiBCM, how difficult is it to 'go back' to the stock NiMH configuration?
A: The simplest method would be to swap your LiBCM-equipped IMA battery enclosure with an unmodified NiMH pack. In that case, the only remaining modification would be the single cut wire on the MCM harness. However, reconnecting that wire is trivially easy: just plug the ORG & WHT Anderson connectors into each other. That's it... now your car is NiMH again.
A: If you want to convert an LiBCM-equipped IMA battery back to NiMH, then you'll need to follow the installation instructions in reverse order. If you followed the "I might switch back" instructions (outlined in the installation videos), then you'll need to splice a few wires back together. You'll also need to cover up a few holes drilled into the plastic enclosure.
Q: (Beta) Why do I have to recompile the LiBCM firmware to change parameters?
A: The firmware will eventually support real-time configuration (via the LiDisplay touch screen).
Q: How long can an LiBCM-equipped vehicle sit without damaging the battery (e.g. airport long term parking)? Will LiBCM over-discharge my lithium battery?
A: Over-discharging is unlikely. When the car is off, LiBCM essentially turns itself off. In the off state, LiBCM consumes 1% of SoC every 15 days.
A: If you parked a completely empty (10% SoC) LiBCM-equipped car at the airport, you would not damange the battery for at least 5 months.
A: Long term parking at 50% initial SoC would take 2.1 years prior to damaging the battery.
A: Long term parking at 85% initial SoC would take 3.5 years prior to damaging the battery.
Q: I plan to park my vehicle for longer than the above-indicated period. What should I do to prevent over-discharge?
A: Turn the IMA switch off, which drops power consumption zero.
A: Leave the IMA switch on, and plug in the grid charger.
A: Charge the pack prior to long-term parking (each 2% SoC increase adds another month to long term storage)
Q: (Beta) While compiling the firmware, Arduino displays several warning messages. Are these important?
A: Probably not. I get warnings, too... it's the compiler trying to be helpful.
Q: Why won't LiBCM work if the safety cover isn't installed?
A: To prevent you from installing LiBCM into a car without the safety cover installed
A: You can disable this in firmware, if you know what you're doing... but really just install the cover.
Q: How does flipping the IMA switch off differ between the OEM NiMH pack and an LiBCM-equipped pack?
The OEM switch cuts the NiMH pack voltage nearly in half. If the pack is resting at 160 volts with the switch on, then turning the switch off will split the pack into two segment, at 96 and 64 volts. FYI: both voltages exceed the UL definition for "high voltage" and Honda has taken care to adhere to the additional design principals that are required in high voltage applications.
LiBCM behaves identically, except that the switch no longer cuts the pack voltage in half. In the same example as above, the 160 volt resting voltage would become a 40 volt and a 120 volt segment. This is required because I'm using a 12S BMS IC with 18S packs. This means there are QTY3 LTC6804 ICs measuring the cells on QTY2 18S modules. One of those LTC6804 ICs is measuring QTY6 cells from one pack and QTY6 cells from the other. You can't cut the pack voltage across an IC, because that would develop the full pack voltage across a single LTC6804 cell... which would cause it to explode.
So the issue isn't materially different between OEM and LiBCM... in the OEM case the 80 volt pack voltage is slightly lower, but it's still high voltage and must be treated so by the Honda design team.
The safety concern is therefore when LiBCM's clear cover is removed... in that case if you touch two high voltage segments of the LiBCM PCB, then you could be touching up to 120 volts DC. Note that this hazard is functionally identical to when the junction board is exposed... touching the 'right' two junction bars would be 80 VDC, which on paper is the same high voltage.
When the LiBCM cover is installed, there is fundamentally zero safety difference compared to the OEM NiMH.
Note that drop-in LiBCM kits will pose no additional electrocution hazard, compared to an OEM drop-in NiMH replacement battery. The primary concern then is electrocution hazards while performing the LiBCM conversion.
LiBCM inherently deals with high voltage. Even the individual 18S modules technically exceed UL's 60 VDC rating (they ship around 65 VDC, and can charge up to 74 volts). On paper 65 VDC requires the same PPE as 120 VDC. In real life I can attest that 120 VDC hurts more than 65 VDC (which you might not even feel unless you're sweaty). However, on paper the module itself is a hazardous voltage just by itself.
I'm fairly certain all the beta testers will agree that the LiBCM conversion can be performed safely, even in its existing (beta) configuration. In fact, one of our beta testers even performed his conversion on a metal table (which for the record I do not recommend).
The ultimate worry, then, is that an installer is complacent and touches two separate high voltage traces on the LiBCM PCB.
Q: Is it safe that LiBCM's high current cables use 75 amp rated Anderson connectors?
A: Yes.
A: The 75 amp rating is for a continuous load, and with the additional heat-load introduced by adjacent multi-gang connectors (which are not present in LiBCM).
A: Anderson rates this connector to 120 amps for five minutes (per UL 1977 testing). The IMA system cannot maintain currents this high for this long (this connector is not the weakest link).
A: This specific connector has been used in various IMA-related projects for 15+ years.
Q: After installing LiBCM, my OBDIIC&C keeps resetting. What's wrong?
A: The longer high current leads inside LiBCM-equipped IMA packs can generate increased RF noise under heavy regen/assist. This noise can conduct into the H-Line signal. Honda's H-Line signal is intended to be a debug tool only, and is not used by the vehicle in normal use. However, the aftermarket OBDIIC&C uses this bus to query data from the various vehicle computers.
A: If your OBDIIC&C resets aftrer installing LiBCM, OBDIIC&C's designer recommends:
-placing a 10 nF capacitor between H-Line and GND at the OBDIIC&C PCB.
-adding a 1 kOhm pulling from the H-Line to 5V at the OBDIIC&C PCB.
Q: Why is the 18S+/18S+/12S+ module configuration not supported?
A: The high current leads are long, difficult to route, and require two separate manual disconnects.
A: There are very few 18S+ modules (maybe a couple dozen), whereas there are nearly QTY1000 known 18S- modules.
Q: When will LiBCM support 54S?
A: No idea.
A: When 54S ships, it will require a few cable changes and a new BMS adapter. All LiBCM PCBs support up to 60S.
A: For now you should use 48S.
For the LiBCM PCB, there are zero hardware differences between 48S/54S/60S. Put another way, all PCBs ship equipped to handle up to 60S cells. However, the initial firmware and cabling kits only support 48S.
Eventually I will release cabling (and a firmware update) for 54S, but note the following:
-I'm going to develop the LiDisplay touch screen prior to starting 54S
-It's possible a 54S configuration with QTY3 18S modules might not fit cleanly inside the enclosure... I still have work to do to figure out how to route the cabling. 54S hasn't received even 1% of my focus compared to 48S.
-A 54S pack will only produce slightly more peak power than a 48S pack (but of course it will have 12.5% more nominal energy). This is due to hardware limitations with how LiBCM interfaces to the MCM.
-The first QTY100 LiBCM units will probably sell out long before I start looking at 54S
-After shipping the first QTY100 units, it could take several quarters (e.g. 2022Q3) before I can ship more units.
Therefore, if you want an LiBCM kit in the next six months, then I strongly encourage you to purchase a 48S kit, and then use a 48S configuration for the time being.
Q: How much more power will a 54S pack provide, compared to 48S?
A: Certainly there will be more power at higher voltages... but not as much as you might guess. The primary limitation is that LiBCM can only spoof the voltage down to 67% of whatever it actually is... and given that the OEM MCM throttles down current proportionally with voltage increase (above 120 VDC), it won't be as much as you'd otherwise expect. 54S with standard lithium is ~220 volts, which LiBCM can spoof down to 148 volts... so you should expect about 4 kW less than the "on paper" power calculation... somewhere around 25 kW or so, which is only 2 kW more than a 48S configuration.
A: A 54S pack might yield 8% more power than a 48S pack.
Of course you could add external resistors to apply an additional voltage spoof, which would entirely overcome LiBCM's hardware limitation... but that would no longer be "drop in", and would add quite a few caveats to an otherwise clean install. As you pointed out, you'd (probably**) need to replace the OEM DCDC converter as soon as HVDC exceeds 217-218 volts.
Q: Is 60S worthwhile?
A: For standard voltage lithium cells (4.2 Vmax), 60S requires a different HVDCDC converter. 60S can theoretically deliver more power, but it's considerably more difficult to build a 60S pack (compared to 54S or 48S).
A: 60S is primarily intended for lower voltage LiFePO4 (3.7 Vmax) and LTO (2.7 Vmax) cells.
Q: The EHW5 modules are too small... How do I use LiBCM with a larger pack?
A: EHW5 modules are easily reconfigured. An 18S1P pack can easily be converted to 9S2P, 6S3P, 3S6P, etc.
A: Reconfiguring QTY8 18S modules to 6S3P would yield a 15Ah 48S module. You'd also need to connect custom BMS ribbon cables to each module.
A: LiBCM technically works with any lithium module. Nissan Leaf modules are probably the 'ultimate' pack for the G1 Insight. Again, you just need to use custom BMS ribbon cables.
Q: With all this additional power, can Insight spin the tires off the line?
A: Only when the road is wet or has debris... it's still a Honda Insight... just more powerful.
Q: How long to install LiBCM Kit?
A: At this point I can do a full swap in a couple hours, so expect to spend between two and eight hours start to finish. It's a lot of work.
Q: How long will EHW5 modules last?
A: Panasonic rates these cells to 50,000 cycles with the following caveats:
-Test performed at 23 degC ambient
-10%-85% SoC
-Continuous 40 amp charge/discharge (100% duty cycle to failure)
-Test concludes when 80% of original capacity remains
Notes on cycle lifetime:
-If a Honda Insight is stored out of the sun and cold (e.g. in a garage), the EHW5 lithium modules have a nearly unlimited mileage lifetime... they're going to die from old age first (Panasonic rates them to retain 80% initial capacity after ten years). You could completely charge/discharge the pack 3x/day for ten years straight... and the battery is still going to die from old age first.
-Extreme temperatures will substantially increase cell degradation. Panasonic doesn't provide cycle lifetime guidance besides at room temperature, but does specify that EHW5 cells be used from -30 degC to 55 degC. We can reduce the temperature impact by limiting assist/regen at extreme temperatures. For example, if the temperature drops below freezing:
-LiBCM will limit regen.
-If enabled (by the user), LiBCM will attempt to heat the pack (using the onboard balancing resistors).
-With a fully charged pack, LiBCM can self-heat for more than three days non-stop.
-If the grid charger is plugged in, LiBCM will discharge (as above) and also turn on the grid charger (to balance the discharge losses).
-If the cabin temperature is warmer than the battery, LiBCM will turn on the fans (it can do so even when the key is off).
Q: How much will the EHW5 modules heat up during heavy assist/regen?
A: Based on empirical testing, new cells likely won't heat up beyond 20 degF above ambient in even the most demanding use cases.
Q: How 'hard' is LiBCM pushing the EHW5 modules?
A: Way below spec.
A: LiBCM would theoretically approach the EHW5's limits around 53 kW assist. LiBCM is presently less than half that value.
A: Everything I know about these specific modules is located here: https://github.com/doppelhub/Honda_Insight_LiBCM/tree/main/Electronics/Lithium%20Batteries
Q: What happens as the lithium cells age and become more unbalanced?
A: Whenever the car is off, LiBCM will dutifully balance the cells to within 1 mV.
Q: Can an 18S+ module be converted to 18S-? 18S- to 18S+?
A: Not without replacing the entire BMS harness, all the way down to the cell.
A: From a mechanical perspective, flipped the cells is trivially easy. However, the resulting module's terminals will be on the wrong side of a 'flipped' module, hence the current cable lengths won't be the same. If you want to create the correct-length cables yourself, here's the manufacturing drawing: https://github.com/doppelhub/Honda_Insight_LiBCM/blob/main/Mechanicals/Cable%20Construction/HVDC%204AWG%20Cables/LiBCM%20Cables%20-%20RevB.pdf
A: Linsight does not endorse flipping 18S cells.
Q: If I'm having LiBCM installed by a Certified Installer, do I need to watch the safety videos?
A: Yes
Q: What happens if LiBCM fails while driving?
A: ________
Q: How is LiBCM shipped?
A: USA: USPS Flat Rate shipping is included in the purchase price.
A: Other: The first $20 is included in the purchase price. You pay the difference based on the actual USPS rate.
Q: How does LiBCM run when not installed in the car?
A: LiBCM doesn't use the car's 12 volt rail, and is powered entirely from the IMA battery.
A: LiBCM powers on each time the IMA switch is turned on. LiBCM can choose to turn itself off (as required). To turn LiBCM back on, either turn the key on or cycle the IMA switch.
Q: How does LiBCM report state of charge (SoC)?
A: LiBCM's 4x20 Display (and LiDisplay): The actual SoC is shown on the screen, where 0% is a completely empty pack and 100% is completely full. LiBCM uses the SoC range between 10% & 85%.
A: OBDIIC&C: The actual SoC is remapped to mimic the OEM NiMH range. This is required to properly apply regen and assist.
A: Instrument Panel: The SoC is not presently displayed on the dashboard gauge. Instead, the value is always either 19 or 20 bars. This will be fixed in a future firmware update.
Q: What testing is performed on each LiBCM prior to shipping?
A: Each subassembly is 100% functional tested using custom hardware.
A: Each cell voltage circuit is measured, both electrically and thermally.
A: Each BMS adapter undergoes a two-stage test procedure to veridy there are no shorts, and that each wire is routed to the correct position on both connectors.
A: Each BMS adapter is plugged into a known-good LiBCM, and then the voltages are measured.
A: Each PCB is connected to a simulated Honda Insight IMA system, and then each subsystem is tested using the following code: https://github.com/doppelhub/Honda_Insight_LiBCM/blob/main/Firmware/MVP/BringupTester.cpp
A: Each high current cable undergoes a five second, 100 amp test to verify low cable resistance.
A: Each 4x20 LCD display is tested using a known-good PCB.
A: Each PCB is 100% visually inspected twice.
Q: The 4x20 backlight turns on, but I don't see any text. What's wrong?
A: Adjust the potentiometer on the LCD's back side, using a small flathead screwdriver.
A: Turn the key off/on.
A: Verify the 10' cable is plugged in correctly: https://www.youtube.com/watch?v=vtU__58DWYw
Q: Why does LiBCM sometimes emit an audible beep during heavy regenerative braking?
A: (Beta) LiBCM emits an alarm whenever any cell voltage exceeds 4.200 volts. Future firmware updates will more intelligently limit the maximum cell voltage (based on current amplitude).
A: LiBCM will tell the MCM to disable regen before any cell voltage gets this high, but sometimes the delay is too long and the cell voltages briefly exceed 4.200 volts.
A: When the batteries are nearly full, heavy regen can cause the cell voltage to briefly spike above this limit.
A: If the beep stops when you let off the brake pedal, then there's nothing to worry about.
A: If the beeping persists, IMMEDIATE manual user interaction is required (e.g. engage Calpod Switch, place transmission in neutral, etc).
A: Heavy regen produces severe RF noise inside the IMA bay. Even with heavy analog filtering, this noise electrically couples into the BMS cell voltage measurement circuitry, and can temporarily cause incorrect voltage readings during heavy regen.
Q: Why does the bay 3 BMS connector not have latching tabs (like bay 1 & bay 2)?
A: Safety. The right angle connectors used on bay 1 & bay 2 have exposed conductors on the connector side. When only bay 1 & bay 2 are plugged in, the highest HVDC delta on the PCB is relatively low, whereas when bay 3 is connected, up to 150 VDC can exist on the PCB.
A: This connector shouldn't work its way loose once the LiBCM PCB is installed. If you have concerns (you shouldn't), then you can drill a 4 mm hole through the left side of the plastic IMA enclosure, then screw an M4x25 bolt into the hole. Position the hole such that the bolt shaft depth will prevent the ribbon connector from working out (once the PCB is screwed to the enclosure). Based tens of thousands of miles driven during the beta program, this is not necessary.
Q: (Beta) Why is assist current positive (e.g. +50 A), and regen current negative (e.g. -50 A)?
A: The math is easier this way.
A: The behavior will (eventually) change to mimic the OEM behavior.
Q: Can I collect data with an external laptop?
A: Yes. See this video:_____________