I'm new to electronics and I'm trying to build a charging circuit for NiMH batteries. There are four batteries in total. Two are in series, and the other two are in series. Then these are connected in parallel. I need to be able to switch them all to series when I plug in the USB for charging. I have an idea and please tell me if it will work. If not could you give me a way, thanks.
The batteries i'm using are the Eneloop xx which are 1.2v so the USB would work because they add up to 4.8v. I was doing research about charging nimh batteries and found out that it is best to charge them in series and not parallel. So if this wont work than could you help me figure out what will switch it to series?