Lipo chargers or Li-ion chargers must be used to charge lithium polymer batteries. We have a range of solutions that start off very cheap and work up to around about £35

These remarks apply equally to lithium ion and lithium polymer batteries. The chemistry is basically the same for the two types of batteries, so charging methods for lithium polymer batteries can be used for lithium-ion batteries. The lithium ion battery is easy to charge. Charging safely is a more difficult. The basic algorithm is to charge at constant current (0.2 C to 1.0 C depending on manufacturer) until the battery reaches 4.2 Vpc (volts per cell), and hold the voltage at 4.2 volts until the charge current has dropped to 10% of the intitial charge rate.