Looking for a BMS in Melbourne - 3147

[schmidty_81]

Hi, I'm looking for a BMS for my 36V 25AH Lipo that I use on my 500W E-Bike in Melbourne, Aus, 3147.

I've attached some images of the old one that got a bit too hot and burnt out, the only ones I've been able to locate are in china and they say will take 15-20 days to ship, but in the past I've found it's usually more like 6 weeks before they get through customs, etc and I'd really like to get it working before then.

Anyone know where I could get one locally? Or even further away that air mail's?

[heathyoung]

Wow - you toasted those discharge fets! BMSbattery have a decent range (china) and send DHL so they are reasonably quick.

Looks to be a dead ringer of a signalab BMS as used by Ping etc.

Be warned that the chinese have been known to swap the orientation of the pins on those headers (ie. topmost cell where the bottom cell would be - surefire way to kill a new BMS is to just plug it in!).

[heathyoung]

There is one listed on fleabay Aus at the moment too...

http://www.ebay.com.au/itm/BMS-36v-LiFe ... 4ab4e3c0ad

[schmidty_81]

Yeah, it got a bit of a workout and it sure did get toasty. Thanks for the info.

[schmidty_81]

So I got a replacement...

http://www.ebay.com.au/itm/170782582576 ... 5403wt_952

Except it only has 12 Battery wires the same as mine (clearly marked b1, b2, etc), unfortuneately my first one has no b1, b2 markings to speak of, does anyone know if there's a way to tell with a multi-meter or anything? Or if I just trial and error it will I blow myself up?

[heathyoung]

Don't trial and error a BMS - PLEASE!.

B1 is the battery closest to the negative terminal (ie. its negative terminal is the pack negative). B12's positive terminal is the pack's positive terminal.

Get a multimeter and work back. Easy. B1 will be negative(0V), B2 will be 3.2V, B3 = 6.4V, B4 = 9.6V - all voltages are relative to pack negative terminal and approximate.

If you get stuck, tell me how may pins on your battery balance connector and I can help you out.

[schmidty_81]

Thanks Heathyoung, that makes sense. I got it wired in perfect and it works like a charm.

[t3sla]

any more deets on the BMS i was scoping it out on ebay

[schmidty_81]

Hi t3sla, I've had it running for about a month now and it works really well, it's better made than the last one and the heat doesn't seem to build up as badly. I guess if I was being ultra critical I was kind of hoping for the price I paid that it came with some kind of case. Let me know if you've got any questions.