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How do I charge 4x AA batteries using USB? Answered

I'm planning an internal laser sight mod for a Maverick Nerf gun, and I've bought a cheap 5v laser module from eBay. I plan to fit a near 5v rechargable battery, or 4x 1.2v AA batteries, but from my understanding of battery chargers, would the USB's 5v be to low to recharge them (The charging voltage seems to be consistently 150% the batteries' output voltage for all my electical devices).



Best Answer 7 years ago

The type of battery you will use will determine the kind of charging circuit you need. It will also determine weather or not 5V @ about 500mA is enough to charge them. So what kind of batteries are these?

Shadow Of Intentmpilchfamily

Answer 7 years ago

Just the standard Ni-MH rechargables... they claim to have a 3000mAh capacity, of which I am slightly skeptical given they were from china, but they seem to be holding out fairly well.
They'd charge more easily from a USB 3.0 port, especially since my Asus motherboard has a feature for enabling ~3x the power output of a standard USB 2.0 port, but that would still leave problems for charging it anywhere else.
I've ditched the idea of USB charging, and just made an external module which I can remove the batteries from. In hindsight, given the low cost of power adapters, it would have been far easier to just hook up a common charging socket and use a 7.5v mains adapter.