9.5kw gen battery BMS board

webselector · May 28, 2026, 1:03pm

hi all, looking for some advice if posible please.

i have an ac coupled inverter with two 9.5kw batteries instaleld, have been installed for about three years and working fine. on the 22nd May the system went into BMS comm failure, proceeded to connect on and off then nothing. inverter circle light flashing etc. all firmwares are up to date.

what i have noticed is the battery will not turn off, the on/off button on the side does nothing and the green LED’s on the front of the battery stay on, the BMS mobo has a permanant blue light on reather than a flashing one. i have also turned the mcb off on the side.

after alot of checking cables and connections i connected just the one battery that looks like it is working fine(the slave battery and set the dips to master) and the system now works fine but with just one battery.

the faulty battery is around 65% full. or so the LED’s say.

it sounds like a BMS mobo issue to me and was wondering if anyone would agree and if so does anyone know where i can gain a spare one given the current situation with GE.

many thanks for any help.

webselector · May 31, 2026, 10:46am

hi, just to update this which may help if anyone else has the same issu.

opening the front of the battery you will see the board loacted at the top on the rear inside of the battey. there is a red cable supplying power to this board which is connected via a spade crimp, i pulled this off the board and let it power down for 10 minutes. plugged the power cord back in and the battery fired up fine, lets hope this has fixed the issue but time will tell ifthe issue returns.

wrighar · May 31, 2026, 8:01pm

Pic here:

webselector · June 1, 2026, 9:32am

hi, yes thats the one, thank you for uploading that.

mine was instaeed at a 180 degree to yours so my cable must of been end of cable drum !!!

pbroadberry · July 13, 2026, 5:18pm

Mine has just locked up the same. Green lights all on - battery not talking, power switch does nothing. So I’ll be pulling the red connector too. Crazy they only have a soft reset button and not an external power cycle reboot switch.