Charging a small 3.7v battery from USB
Hey guys! I had this little flashlight that worked great for years. I would plug it into the USB port on the computer to charge it. When it broke I took it apart and it had a small battery connect directly to the 5v and GND of the USB cable. Is it OK to charge these small 3.7v batteries from just 5v without having to make a circuit?
Is ok to just hook them up to 5v?