Trojan Battery Company

A deep-cycle battery maker from Santa Fe Springs, California, whose marine and RV flooded line is specified more completely than almost anything else on the market. Where most makers print one amp-hour figure, Trojan print four — at the 5, 10, 20 and 100 hour discharge rates — and reserve minutes at both 25 and 75 amps. That matters because amp-hours do not compare across chemistries. A flooded lead-acid battery gives up less of its charge the harder it is worked, so a capacity with no rate attached says very little; minutes at a stated current is the figure that can honestly be set against a lithium pack's. Two things to know before comparing their numbers with anyone else's. The kilowatt-hours they print are calculated at the 100-hour rate, which is the most generous of the four. And they publish no BCI group size for their marine batteries — the digits in a name like 27TMX are Trojan's own model naming, and the battery is larger than a group 27 tray will take.

trojanbattery.com