I got few new 3.7V phonebatteries (for Samsung I9100) and they would be nice power supplies for some of my projects with 3.3V Pro Mini's. Problem is that I don't have a charger for them.
I have old 5V phonechargers (1.5 - 2 amps) but as far as I know it's not a good practise to charge Li-ion batteries without a controller. I was wondering if I can turn a Arduino Nano, a optocoupler and a phone charger to a tablecharger for those batteries.
Any advice for that? Or will it just blow them all up and burn the house?
Any advice for that? Or will it just blow them all up and burn the house?
Not sure of the solution but get it right. I once attached a charger to a 12 volt battery (probably NiCad) and it blew up like a balloon! Houses have burnt down due to cheap imported battery driven products. So use a charger that detects a full charge and turns itself off. Not sure if this is controlled by a voltage reading or a drop in the amount of current flowing into the battery. I think they sometimes use a temperature sensor in some batteries packs that turns off the charger if the battery get too hot.