Advanced Power Products offers batteries from the best sources in the world.
Among them are:

Duracell Panasonic Ultralife Energizer Sanyo

Varta Enersys Saft GS Battery Tadiran

For technical specifications on cells, or to learn more about a specific chemistry, click on the links below.

Lithium Ion Lithium Polymer Nickel Metal Hydride Nickel Cadmium Sealed Lead Acid

Lithium Manganese Dioxide Lithium Sulfur Dioxide Lithium Thionyl Chloride Alkaline

Battery Chemistry Information