BMZ Battery 'wake up'

[grundholm]

I hope someone can help here. I have a few of these BMZ Cargo batteries and I want to charge them from solar.

Does anybody know how to wake up the bms? The connector has 4 pins as shown on the pictures. When I measure on the two middle legs, there is no voltage. I imagine the two other legs needs some kind of signal/connection to tell the bms to open for input / output.

 

[floydR]

Photo of the bms or the page you got them from would help. Often it is simpler to install a new bms.
later floyd

 

[grundholm]

This is the inside of the battery, I know it doesn't help much - I think you are right about installing a new bms...

 

[floydR]

When you measure voltage at the big positive and negative wires on the bms do you get voltage? might just need to be charged to active the bms or it might take a connector that would plug into the empty socket on the BMS and a doogle specific to the BMS or into a computer/bluetooth to wake it up.
Later floyd

 

[Korishan]

In a lot of BMS boards, there are generally 3 options to try:

1) Connect Negative to one of the other pins
2) Connect Positive to one of the other pins
3) Connect a resistor of a certain value between the non-Pos/Neg pins

And sometimes even #1 or #2 could include #3 option, adding a resistor of a certain value to one of the other pins.

Without knowing what the chips are on the BMS, it's almost impossible to guess, unless you can find datasheet, or other information about the model of the unit.
"Guessing" what to do could end up blowing the BMS anyways. Soooo, without finding any information readily available, I'd toss the BMS and put a new one on it.

 

[floydR]

Have you looked at the battery manufacturers page/www.bmz.gmbh,de page I couldn't find anything on bmz.gmph.de the bms looks well built has at least two temperature sensor I believe.
Is this connector connected if not will it reach and fit the empty socket?

low voltage cut off may been triggered. Bypass bms and charge while closely monitoring might reset the bms.
Later floyd

 

[grundholm]

1) Connect Negative to one of the other pins
2) Connect Positive to one of the other pins
3) Connect a resistor of a certain value between the non-Pos/Neg pins

And sometimes even #1 or #2 could include #3 option, adding a resistor of a certain value to one of the other pins.

I tried that today, but still without any result, I measured 19,5V on the thick black and red wires, it's very low for this kind of battery, so the theory about low voltage cut-off sounds right.

Later today I read in a German forum that BMZ batteries use encrypted CAN-BUS - so goodbye bms...