Normal root cause to resting battery fault is that one cell or entire pack is under low voltage protection limit. Is that likely given the battery voltage now? Does it take charge if you connect to charger?
If you want to decode the CAN messages you can start by sorting them by the CAN identifier and see which IDs belong together. There will likely be some patterns visible, for instance a group of12/14/16/whatever series number of lithium cells voltages that lift use. These IDs will be similar in content and updated regularly with the same period. If you are lucky these will be in uncoded numbers and you only need to find if they are little endian or big endian to decipher them from hex to decimal in a CAN program like busmaster.
(This is not really my expertise, iāve only set up some CAN stuff. If you want to find more skilled CAN people then iād go to diyelectriccar or openinverter forums and ask for help.)
Anybody know what 2 yellow soild lights mean while trying to charge? Battery wont charge at all. Did a battery reset and firmware update nothing works to fix the battery. Anybody been able to fix these batteries yet. Ive been like this for over a year now and cant ride my board.
Charging
a. If One LED is Blinking Green at 2 Hz: More than 2 Amps of Charging Current is Flowing
into Pack.
b. If One LED is Blinking Yellow at 2 Hz: Cell Voltage Imbalance of >100mV is leading to
reduced charge rate. Cell Balancing is active.
c. If LED1 is Blinking Yellow at 1 Hz: Battery Charge Current is Limited due to High
Temperature.
I think it was first and last, it just looked like all were red because of the light leak in between the LEDs, the LED pipe isnāt a great design.
Anyhow, I went to take a photo this morning and nothing from the battery, not a good sign, I went ahead and opened the pack, I measured some very low cells. Trying to save them with a slow current controlled charge but I donāt have much hope. Should have done so earlier, damnit!
Hereās a photo of the opened pack and the tools I used to commit the crime:
I sharpened the red scraper and tapped it in gently all along the edge the seam. I then used the small flat head to open up the seam along the inside of the handle. It opened clean.
You will not succeed.
The error indicates a defective BMS.
What is the serial number of the battery? Severe Battery Fault
LED8 Red: Severe Battery Fault is Active. Battery operation is prevented for safety reasons.
Other LEDs Indicate which fault conditions are present.
connect the battery to the charger again. which leds light up red?
I think itās mostly the a group of cell that failed, and since I wasnāt able to charge it itās now at 0v and gone, I should have opened the pack sooner. The BMS looks intact. Nothing light ups right now as I have it fully disconnected. I am charging all the other groups one by one as they are low in order to keep them healthy, then I might attempt replacing the failed group. I have extensive experience working for the EV industry and feel confident about working with packs like this. My only concern is not being able to reset the BMS, I am not sure if it will store the fault or recover once the cell groups are back to proper shape. We shall see I guessā¦
A LIFT battery (BMS) can be reset by pressing the ESC power button ON for 5s. You need a LIFT board to do that [GUESS mode ON: or emulate the sequence applying a +5V on the relevant BMS pin]
How integrated are their battery and bms to the other parts then? Normally BMS takes care only of battery so you could switch to any bms you like without affecting the system. A smart bms can replace the cell voltage display if there is any, as long as ESC doesnāt go into protection from needing CAN messages to runā¦
I have not understood whether you want to use the repaired LIFT battery in a LIFT board with a LIFT ESC or not.
I understand @Larsb point in a sense that even a washing machine can work with bypassed safety devices. The question is : can a LIFT foil work when the CAN bus connector coming from the genuine battery is not connected to the CAN connector of the electric box containing the ESC ?
If yes, the original LIFT battery BMS can be replaced by any BMS.
If no, the ESC has to be replaced OR a small CAN dongle has to be developed to simulate the original BMS presence.
The answer is no, it wonāt operate without communication. I am simply trying to repair a lift battery to use on a lift board, thatās why I need to keep that BMS. Iāll keep you guys updated on progress.
A lot of BMS chips have options for a permanent fail internal fuse that is unrecoverable without removing/replacing BMS. Basically they could do something where if the cell voltage drops below 2V a cell then it wouldnāt let you charge or discharge anymoreā¦
Or it could only be that getting all the cells to the right levels could bring it back to running again.
If ran a battery business Iād probably be doing the first optionā¦ way less liability.
i hate CAN, on my cars , on my wife bosch ebike ā¦ a pain to reset sensors, calibration ā¦ and erase error, indeed for safety feature you need a high access level
@brycej : yes i have save several battery pack by just bypassing the bms under voltage feature by charging the cells past 3.0v
another i needed to change the bms
@Theocerbo
i guess the question here is why you go a full 0v row? i donāt think its gone , i wouldnāt use it for sure, but i would not mean (with safety) try to charge this row to 2.8-3.0v (itās like 20%) q30 are pretty good cells
at least get all row to about 3.0v , do a āresetā ,to see what the bms think of it
have you tried ? or run a IR test ? CID opened ? most of my dead cells from low voltage revived (just tested for science), only a few were out , so far i have one GA cell who lets me go just like that
Not necessarily. If changing the faulty cells doesnāt work to restore the BMS CAN functions, you could simulate your genuine BMS by connecting a dummy one, a microcontroller (Arduino, ESP32, ā¦) to your electric box that will not detect the change.
Track#1: as an optional free software test solution before Track#2 the hardware solution
Traffic analyser to monitor, analyze and simulate/generate an CANopen āOK answerā to the electric box.
Free : Wireshark with CANopen module
Commercial Professional CANopen tool: CANopen Magic - Home FREE to test for a week.
Once the tethered software emulation is validated, emulate with a tiny standalone hardware solution (microcontroller) here below.
If this is too heavy, you could program your Arduino like an HTTP server sending an HTTP āHello frameā to send the CANopen OK code frame found in the āGOOD_batt.txtā file with the right sending NodeID address upon each request or at the right period saying āIām fineā.
