Hello, good afternoon, my question is this, I have a battery of a 3.7V and 800mAh cell phone, I would like to know how to charge it without damage, I do not know if it can be connected directly to the cables of a 5v charger or a USB port since the battery is 3.7vo should be used with some resistance. What I want to do is connect some LEDs of a small flashlight to the battery so that it can be recharging and not have to change the batteries.