I recently bought a bestech d140 to replace what my old d140 that blew, but they seem to differ a bit.
my older bms had a 8 prong connector, and this one had a 9 prong connector, but that didn’t stop me from connecting it and running it with a loose prong stickin out.
Anyway, this is how I plugged it in, and my fear is now I have an unbalanced P pack because I did something wrong.
Tell me, is this correct, thanks!
@JLabs any help would be appreciated
August 30, 2018, 10:14am
your balance b- not connected now
like this your bms can´t measure the voltage for each serial pack.
how the bms before was working? got the balance b- from the main - on the board?
probably, if not I guess you now would already have a short and broken bms.
This new batch of d140 bms has two b-. One on the board like our old ones, and one on the connector. I don’t have the answer but I’m following as I’m having the same problem.
I was planning on using my multimeter to see if the two b- places are electrically common to each other, I.e. 0 ohms when checked across the two. If so, I assume it will be safe to only connect one
On few of BMS here I see that there is a through-hole for balance B- connector and they sometimes come with full balance count connector (series count + 1) or sometimes they skip that pad because main B- is already connected. Balance and main B- are connected of course (you can see traces on PCB or check with multimeter if you’d like). You’ll be fine.
August 30, 2018, 12:21pm
It’s not the same as other connectors. You will need to attach the B- wire. I would just install the new wires on the battery
August 31, 2018, 12:15am
your old D140 probably has the b- internally wired up from the big B- for the battery lead. it’s safest to wire a new b- lead from the battery to the b- balance lead.