bms with canbus

rrrobertson

1 µW
Joined
Dec 8, 2018
Messages
2
I rebuilt an A2B Galvani/Ferber 36v battery only to discover the CANBUS is not working on the BMS. The battery charges fine and shows the correct voltage along the balance wires as well as the output side. When plugged into the bike it displays: "2E d".
According to A2B:
error code "2E - d" is the result of a communication failure from the battery. (Thus my theory on CANBUS not working)
I have verified all connections on the bike are functional. This is backed by putting a pack from a brand new ferber into the galvani and everything works. Additionally i put the 'broken' pack into the brand new ferber bike and the display results in the same error.

My question is, what is a suitable BMS that provides CANBUS i can replace in this pack?

Thanks.
 
CANbus is just a protocol.

Commands/data/etc are all device specific.

So unless you reverse engineer what the A2B BMS should be sending for each query by the controller, and then figure out how to program that into a new BMS, or build a microcontroller that interprets each way for each device so they each get what they expect, then no other device except the original one is going to respond correctly (if at all) to teh controller queries.

There are probably threads here (or elsewhere on the web) of people that have started (possibly completed) that reverse engineering of command/data sets for some A2B stuff, so if they have done yours, it would at least get you that far.



But before you go there, you might check the connections between BMS and rest of system to be sure it's not just that, rather than a failed BMS. Connection problems in wires, contacts, connectors, circuit boards, etc., are the most common cause of failures of most devices that I've ever worked with, regardless of age, quality, etc.


It is also possible that the BMS is "booby trapped", so that removing power from it (during the battery rebuild) resets it or loses data in it, so that it no longer "knows how" to talk to the rest of the system. It wouldn't be the first system designed to fail like that, to prevent non-factory/dealer work being done on it.
 
I can tell you from personal experience the bms will still work fine after a rebuild on this bike (assuming it was fine before). I have also been looking for replacement bms boards for these with no luck yet, not because I need one now but I'm sure I will someday. Figuring out the canbus info would be worth some $$ if anyone can do it. Good advice (amberwolf) on troubleshooting techniques and usually the factory bms boards are decent and it's a bad connection, etc....
 
I am having the same exact issue. Battery rebuilt by ebikemarketplace. They have sent it back to me three times. Each time there is a new issue the most recent being exactly what’s described above. Has anyone found a solution that can be made. I am in contact with customer servuce from A2B and they don’t have a date for new replacement batteries.
 
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