Also called Li-Ion. A rechargeable battery technology that is similar to Lithium Polymer. Lithium Ion batteries have a greater charge-per-pound ratio than Lithium Polymer batteries, but are not as flexible. Both Lithium Polymer and Lithium Ion batteries have a greater charge-per-pound ratio than Nickel Metal Hydride (NiMH) and Nickel Cadmium (NiCD) batteries.