I have a project in mind based around a Raspberry Pi Zero. The case I am using has slots for two AA batteries so I thought I would use some of the AA sized Li-ion batteries.
The batteries I want to use are 3.7V 2300mAh.
The charge circuit I found is: http://www.banggood.com/37V-Liion-Battery-Mini-USB-To-USB-A-Power-Apply-Module-p-928948.html
Ideally I would like to have two batteries in parallel so I could get 4600mAh, but I know there can be issues charging and discharging in parallel, plus I have no idea if that charge controller will do that.
My next option is to just use a single battery with that charge controller, that seems the easiest. Although I cant actually find any reliable info saying this circuit can charge Li-ions, Can I use anything advertised as charging Li-po on Li-ion?
One other option would be to put the two batteries in series and an LM7805 to bring the voltage down to 5V, would this be suitable? I would use an external charger that way.
Sorry for the broad question, if I use google all I get are things for Li-po batteries, and if I look for Li-ion charge modules all I get are the external type.
I am pretty good with amateur electronics, but I've never worked with these before and I don't want to get it wrong.