I am building a small high quality headphone amp which needs power supply +/-7V up to +/-17V. According to the manual it uses maximum 200mA.
I like to use 2 x 3 16340 rechargeable lithium batteries because they are relative small. I think it is necessary to make sure the batteries are not discharged too low. This is why I think about using a BMS (battery management system). I plan to use two of these BMS:
To charge the batteries I think about using a RC hobby balance charger for 6S charging which I will connect when needed.
I will never use the amplifier while it is charging. There will be a switch which connects the batteries either to the amp or to the charger.
For the balance charger I need to connect all individual batteries to the charger. And all the individual cells are connected to the BMS.
Now my question is: Is it ok when all cells are at the same time connected to the BMS and connected to the balance charger? Or do I have to disconnect the cells from the BMS when I charge them with the external balance charger?
Or what are the alternatives? Is there another easy way to make sure the cells are not discharged below a certain voltage?
Or should I charge the batteries just by applying 12.6V, 500mA to the BMS and let the BMS handle the charging?
About the BMS in the picture: I think about using that model because I could buy it easily and it's cheap. I looked at big electronic distributors and I didn't find any BMS in their shops.