Battery protection board not working correctly.

[kenzo51]

Hi gurus. I bought this little battery protection board and wired up 2 18650 batteries per the attached diagram but get no power at the "P" side. When I attached the batteries at the P side, the B side has power. Can any guru tell me what I'm doing wrong please?

 

[rjenkinsgb]

You may have to connect the P side to a charger temporarily to get the electronics to switch on.

Also note that the board appears to provide undervoltage / overvoltage protection, but not balance - you must also have balance for the cells to properly charge as a pair, otherwise charging will stop as soon as either cell reaches maximum voltage.

It's OK as it is if you are using a battery holder and charging the cells separately.

 

[Nigel Goodwin]

As already mentioned, you simply need to apply power (8.4V) to trigger the protection circuit to life.

We replace a LOT of faulty cells at work, and very often they don't work with new cells fitted and you need to give them a quick 'kick' with a PSU.

 

[kenzo51]

Wow. Thanks so much guys. That little kick was exactly what it needed. Awesome. Have a great day!

 

[billybob]

Is it just me or is c1 missing in the second picture?