There is a dumb charger and a smart charger (these are the $300 ones)
Read up on Lipo Batteries before crossing that bridge make sure its what you want as it gives you different results than a reg battery.
Dumb charger you have to time how long to have the battery plugged in or you can damage or ruin your battery. Its recommended that you drain your battery fully before recharging. These run around $20.
Smart charger stops charging the battery when it is full and still plugged in, this reduces damage and extends the life. Smart charger prices vary. Some chargers have a decharge or drain option that allows you to full drain the battery before recharging.
If you do things right you shouldnt have any issues with a dumb charger. But if you want to be more carefree with your charging and set and forget then get a smart charger.
ICS M4A1, VFC SCAR-L, KJW 1911A1, KWA USP COMPACT