If you are thinking of an 1/8 scale electric, which typically use a 4S lipo (or more in some cases), be sure to get enough power. At least 100 watts of charger power, 200+ is better.

The B6 chargers mentioned are 50 watt maximum and will be limited to around 3 amps on a 4S, which is very slow, up to a couple hours to charge typical 1/8 lipos. This is a very common issue, we frequently get threads asking why the charger won't go past 3 amps when set higher.