Electric motorcycle Super Soco 60v 45AH issue.

[glyndwr]

Hi all,
I have recently picked up 2 super soco batteries, both have gone into sleep mode after the original owner stored them and left them for ages, and they went into low voltage cut off protection mode.
The battery is a 17S nmc battery.
Spoke to the manufacturer today, they told me that the bms goes into sleep mode after the battery drops below 54v
and goes in to protection mode when the battery drops below 50v.
both batteries were sitting at 49v.
Worked out the pinouts from the bms signal connector and leasured the cell voltages all cells were at 2.88v.
I used a lab psu to raise the battery to 58v very slowly where it is sitting now, its not self discharging and seems fine.

The manufacturer tech support told me that when the BMS enters protection mode, it cannot be restarted, and the BMS Logic board needs to be replaced.
Has anyone got any ideas of how to reset / restart the BMS, even if it means replacing a component on the pcb that has switched it into protection mode.
It seems a shame to replace the bms when it looks in great shape, apart from a internal electrical component / gate switch shutting itself off.

Thanks,
Anthony.

 

[amberwolf]

Most BMS these days use some form of MCU (small computer chip) instead of just discrete hardware bits to control everything. A safety feature of the software to "brick" the battery for overdischarge is not intended to be defeated or worked around, and would have written data into the MCU itself to prevent further operation (rather than some external part). It's pretty likely this is permanent, and unless you know the specific MCU memory location to use some external program (that you'd have to write) to write to, and what exactly to write there, it's not undoable.

If the lockout is inside the MCU itself, so is the software that runs the BMS, which you almost certainly cannot get, so there's not really a way to replace a part to get around this, *unless* the MCU is a standard BMS chip (and not a generic MCU) that comes from the chip factory (not the BMS factory) with the software built in, in which case a new chip would be factory-fresh and not have any lockouts in it yet. But, if it requires any kind of setup to work with the BMS hardware it's installed into, etc., that has to be done by the BMS factory or the bike factory, it may not work to do this either.

You could try disconnecting the BMS from the balance connector to the cells *and* then the main B+ and then the main B-, so ti is not connected to any source of power, wait a while, then reconnect it in the reverse order. Sometimes this resets a BMS, but it won't reset a deliberate bricking by the BMS software for safety reasons.

If none of those things are possible, or they don't reset it, you probably *will* need a new BMS.

If the BMS is a standard type and doesn't communicate with the rest of the bike, you can use any other standard BMS that has the same ports / functions / current capability.

If the BMS talks to other parts of the bike, you will almost certainly have to get one from the bike manufacturer to preserve whatever functionality that communication enables. Some bikes are built around this comm, and if it isn't working the bike doesn't work. .

 

[glyndwr]

Thanks Amberwolf.
I`m going to try the manufacturer today to see if they can suggest anything, i work on the premis of repair rather than replace, even if i have to send them the bms logic board back to them to rework / refurbish, rather than scrap it off.
O tried what you suggested, it made no difference, so im this case it seems the bms logic board has sacrificed itself to save the battery.
Its a shame the maker didnt put in an "engineer" fix for this to save the pcb, the expense and the components from the scrap bin.
Thanks
Anthony.

 

[amberwolf]

The reason they don't do that is because usually the reason they have to brick is cells have dropped so low that they are damaged, and could start a fire if recharged (either immediately or at any time in the future).

It's always possible the factory has a way around it, using equipment that they have there, but they wouldn't let that out to end-users because they don't want the legal responsiblity for whatever happens after the user does the reset without first replacing all of the cells (and even if the user did, there's not much likelihood they'd be able to do a decent job of it or get good cells, etc-even of those that come here few could or would do it right, and even fewer outside of places like this).