I have 12 18650 batteries. They are in series of 3 to achieve 12v and also in parallel for more capacity.
circuit.png

There is a crude image of how they are connected.
Here is the link to the protection board I am using
https://www.amazon.com/gp/product/B01LXAQUG6/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
There is an image that shows how to hook it up to the batteries for more information.

My question is how can I charge the 18650s. Im decently new to battery circuits and charging.
One of my ideas was using physical switches to disconnect everything so that the batteries are only in parallel with 3.7v and then using a USB charger that I had to charge them and when charging was done I could unplug the cable and flip the switches back.
I dont really want to do that because 1. Its crude 2. its ugly 3. Its dangerous because if I accidentally flip the wrong switches it will short out the batteries



For the people who want to know the project to get an idea of whats going on inside, its a 120vac battery pack. 18650s --> protection board --> switch --> 12v inverter


Thanks in advanced for any help. Im just a novice at this haha

 

Welcome to AAC

Google Balanced Li-on Charging. Study it first and then we can go on from there.

 

You just put the charger on the P+/- terminals when the cells need charging, the pcb does the monitoring.

 

You just put the charger on the P+/- terminals when the cells need charging, the pcb does the monitoring.

This board does not have balance charging though but im not too worried about that. Would I use 5v or 12v to charge the batteries and are you sure I can connect the charger to the pcb? I really dont want to destroy anything or have my batteries blow up

 

I ask that because 6 of the batteries are protected with a capacity of about 2600mah while the other 6 are unprotected with a capacity of about 2250mah

 

I use these pcbs with a charger permanently connected to the P+/- terminals, and they're always fully charged never been any problems, then when the mains fails the batteries take over.

 

I use these pcbs with a charger permanently connected to the P+/- terminals, and they're always fully charged never been any problems, then when the mains fails the batteries take over.

Alright I can do some testing once the board comes. Damn products from China, take forever to arrive in the US.
So I take it that charging voltage is 12v?

 

Yes about 1v more than the maximum voltage.