batteries, material, voltage

Carbon zinc - non-reversible, 1.5v

Alkaline - non-reversible (basically, but some reversibility can be forced) 1.5 v

NiCd - reversible - 1.2v nominal, 1.35v fully charged, 0.9v discharged

NiMH - reversible - 1.2 v nominal, 1.35 - 1.4v fully charged, 1.0 v discharged

Lead Acid - reversible, 2.0v discharged, 2.3v charged

Lithium Polymer - reversable - 3.7v nominal, 4.2v fully charged, 3.0 discharged

Lithium Ion (LiFePO4) - reversable - 3.3v nominal, 3.6v fully charged, 2.8v discharged