Panasonic BMS board

[rovtec]

Hello ,
new user to this forum , does anyone know of a way to talk to the M37510 chip on the Panasonic BMS boards used on the DARBY Cycle batteries used on Kalkhoff bikes
When I purchased the bike some two and a half years ago I bought a spare battery for touring , and recently just a few months after the warranty ran out my spare went dead , I have opened the box and discovered its a fairly simple affair totaling 70 cells .
the re sellers of these items want over 700 euro for a replacement battery , I am not inclined to buy a new battery !

Pack1 42 18650 cells 6 banks of 7 in Parallel.
Pack2 28 18650 cells 4 banks of 7 in Parallel giving 36v @14aph

The controller board appears to use the M37512 BMS controller chip , I can see the I2C clock and data line and the leads off the cells are clearly marked and color
coded so I don't see any problems replacing the cells as I have access to a small spot welder and I fully intend to replace all the cells (at least the ones I cant revive)
my problem is when I do replace the cells and reconnect up the BMS board how can I get the new battery information into the board , I assume the controller
will have stored all the parameters of the old cells (from when the pack was last working) , is there a simple way to communicate with the board or am I better off
buying a completely new BMS board and replacing it when I replace the cells ,??

any help or suggestions would be appreciated !
rovtec

 

[Nobuo]

Welcome!

First, how the BMS is connected to the battery?

Usually BMS has the B- main battery lead soldered to the PCB and then from the PCB you have discharging B- and charging B-.

Balancing wires between all the paralleled groups, are sometimes connected to both main poles, or using the main B- wire also as a balancing wire.

Then BMS main pole "-" with battery main pole "+" are connected directly to the controller. If is working in this way, I would just completely rebuild the battery with new BMS and new cells, matching with similar specs.

If you want to exchange only cells, it would work if they are same nominal voltage (usually 3.6V)and max voltage (usually 4.2V). But You shouldn't never exchange only bad cells, in that way the battery will have paralleled groups and the series with very different "personalities" making a hell for the BMS balancing the whole pack in each charge, and also wasting energy on higher practical capacity cells.

Some photos of the hardware would be very informative

 

[dnmun]

do you still have the charger or just the pack?

do you need to use this BMS to make the bike work or can you use a normal shunt balancing BMS?