Batteries Plus sells Duracell Ultra car batteries that are manufactured by East Penn Manufacturing. They also sell absorbent glass mat batteries under the X2 Power brand manufactured by the Swedish manufacturer Northstar.
AGM batteries have become increasingly popular, since they are spill-proof. They absorb battery acid with a very fine fiberglass mat, and thus can be shipped as non-hazardous materials.
Expensive automobiles typically use AGM batteries to run heated seats and other power-hungry accessories. The new "stop-start" function in passenger cars also necessitates a more robust battery than the traditional "flooded' type found in most cars. AGM batteries are also preferred for upscale motorcycles since they prevent spilling in accidents. NASCAR and other racing vehicles also use them. Their higher manufacturing costs are reflected in their retail price.