What is the best way to charge Lithium Ion batteries?
The Battery University (Cadex) states that Li-Ion batteries have very strict charging regimens as specified by the manufacturor. The battery must be charged using the technique and equipment indicated – there is no magic charger. Like alkalines and lead-acid batteries, the charge state of Li-Ion batteries can be determined by measuring the voltage of the battery. Typically, cells are at full charge at 4.20V and near half charge around 3.80V. Li-Ion batteries usually will not discharge below 2.50V, since that is when safety circuitry will open making the battery appear dead. Allowing a Lithium Ion battery to discharge to 1.50V or lower will cause damage to the battery that will prevent safe recharging. Do not attempt to recharge such batteries. Note that lithium Ion and Lithium Ion Polymer batteries are similar, but the latter use a gel based electrolyte. Based on an article from the Battery University on Charging Li-Ion batteries.
