Rechargeable Li-ion, Li-Poly and Lithium Iron Phosphate (LiFePO4) batteries differ from the standard Lithium batteries in that the latter are not rechargeable.The lithium-ion batteries Li-Ion usually have a nominal voltage of 3.6V or 3.7V., The LiFePO4 have a nominal voltage of about 3.2V or 3.3V and the lithium-polymer Li-Po batteries have a ...