Help with JBD bms

[Dawry]

Hi!

So i built this 18650 power pack.
24v 7s 18650
BMS: JBD SP22S003A 40A

Now i need to fint a way to charge it.
Im planning 2 separate ways.
1) With solar.
I have 39v 350w solarpanel, cheap pwm controller and well...my power pack.
2) With 29.4v wall charger.

My questions are:
1) JBD bms has bluetooth, in the bms app are switches

If i have them both on, i cant charge it.
If i have only the charge ON, it takes charge but dont discharge.
So, do i need to configure them every time manually? (when i charge and discharge them)

2) Can my bms handle overvoltage?
In case my cheap solar controller lets too much voltage in.
3) Can i plug wall charger directly to BMS or not? (charger voltage 29.4v)


If somebody wonder why cheap controller - well i had it laying arround from previous projects and same goes for the solar panel.
Pack is just for emergency use.

 

[sunshine_eggo]

1) There should be a toggle in settings that enables/disables manual switch control. I have found enabling that to be problematic. Try disabling it.
2) If you have a 7S BMS for 3.7V chemistry, and it's properly wired, it certainly should.

Consider testing by setting the limit arbitrarily low to confirm that once you start charging, the BMS cuts off charging.

3) 29.4/7 = 4.20V, which should be consistent with peak voltage of 3.7V chemistry, so yes. If you didn't balance your cells, you may notice that one or more hit 4.20V before the others and cause premature charge termination.

You also might want to try an older version of the app. I hate that one. The overkillsolar app should work as well, and it's pretty decent. Notably better IMHO.