wrong BMS

[robo4]

hi guys
so I have been sent 2 14s BMS's when I ordered 13S's
I read here that it may be possible to use them as 13s

is there any tricks to this ?

 

[fechter]

It depends on the style. Post a picture of the circuit.

In general, you can use it by tying the cell 13 and cell 14 lines together.

 

[robo4]

here's the blury pix
(bit like my eyesight)

i'll try the 2 wires together an see if a battery will accept a charge and balance

I was wondering if I should just de-solder the SMD in the 14'th channel ?
but putting the 2 wired together seems like it will have similar results

 

[fechter]

It should work fine. Each channel is powered by the cell it's connected to, so if you short 13 and 14, the last channel won't be powered and the parts won't hurt anything. Also reversible if you later want to use it for 14s.

Just be careful about the connection sequence to avoid blowing up the board. Start by connecting the B-, then the balance wire plug with a slight angle so the lower cells make contact first, then lastly the B+. Most of the time it doesn't really matter much, but I've seen plenty of them where it did. The main thing is to avoid is connecting the B+ before the balance plug.

Also double check the balance plug wiring before plugging it in. Best is to use a voltmeter between adjacent wires and make sure each one is a single cell voltage.

 

[robo4]

I have tested I on a 1P setup and it seems to work with the 13 and 14 wires connected
will test on the battery I an going to use on to make sure

thanks for the info on this fechter