Did you check for writing on the backside of the top PCB?
no, it would require desoldering a 7 pin sil which is connecting the two PCBs. I really, really hate desoldering those things
B0-B10 right to left. Grab your multimeter and set it to check continuity. Check between pins b0 and b-
it should be easy to check if the first and last balance pins are connected to positive and negative using continuity check on a multi-meter. if so the other 9 pins will be the intermediate balance points and it will also tell you which direction they go in.
@ducktaperules - nice thinking there mister! I deserve a slap for not thinking of that myself
we have continuity between B- and the far right pin, which must therefore be Battery 0 / -
and of course, having worked it out independently I just got an email from BesTech.
Lucy all is forgiven
Steps for how to connect the PCM with cells in order.
- Connect Pack’s negative with B-;
- Connect cell 1 with B1;
- Connect cell 2 with B2;
- … 11.Connect cell 10 with B10; Then measure the cell’s voltage in order to see if the voltage is progressive increase.If yes,you can plug the connector to the PCM in order. Also if the connector and wires is not matched,please don’t plug,or the PCM will be damaged. 12.Connect Pack’s positive with B10; 13.Connect Load’s negative with P-; Connect Charger’s negative with C-; 14.Connect Load’s positive with B10; Connect Charger’s positivewith B10;
Sorry for digging up an old thread, but I just wired this BMS together and thankfully no magic smoke…
But I have 2 questions I wanted to ask:
- When the E-switch is disconnected, the voltage across the load output is an odd 27 volts as opposed to what I thought would be 0.
- Do I need to turn on the E-switch to charge the BMS?
- is normal
Thanks but wont this mean there would be 27V going into my VESC even though the E-switch is turned off?
no, it wont do it under load.
it’s something to do with caps, blue smoke and voodoo there more technical descriptions of why to be found using the search
Great… thanks a lot for the assurance! Was getting a bit worried I messed up!!
can somebody point me to where to buy this BMS?
You can order directly from Bestech: http://bestechpower.com/
I also have one of them for sale (EU), because you have to order two at a time unfortunately:
Just to help some people out since I had some trouble with this (I got the answers from @pjotr47) Here is a screenshot of how you should connect your wires
Solder your wires on those squares the arrows are pointing at.
The 11 (!) balances wires need to be wired as follows: Left to right when viewing the BMS as in my photo 10, 9, …, 3, 2, 1, B-
does this diagram seem right for wiring the balance leads on a 12s? https://esk8content.nyc3.digitaloceanspaces.com/uploads/db2454/optimized/3X/8/3/839c1e65e39ce3fb4349d203ad20d3e611fb4519_1_375x500.jpg
Please complete the wiring. There are some leads missing. It looks like you wired the cells in a random order
Also, the first pin (from the bottom) is supposed to be connected to ground, if I’m not mistaken.
Quite a noob question: trying to understand where the e-switch is as it’s not marked clearly anywhere… Could anybody help with this (while waiting for bestech response)… Thanks
the e-switch is the two white wires that are attached to the BMS, you will need to attach a latching switching/button to those wires
Thanks for the answer. It turned out Bestech sold me the non e-switch version in the end so will have to think about the alternative (the two white wires I have are for the temperature sensor apparently).