7 3/8 x 9 1/4 T echnical / Build Your Own Electric Vehicle / Leitman / 373-2 / Chapter 8
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Build Your Own Elec tric Vehicle to the acceleration and top speed performance your EV can get out of its batteries. • Energy Density (Orgravimetric Energy Density)—Also known as specific energy, this is the amount of power available from a battery for a certain length of time (under optimal conditions), measured in watt-hours per pound of battery weight. It translates directly to the range performance your EV can get out of its batteries. • Volumetric Power Density—This is a factor more of interest to the technical battery community working across different battery chemistry types. It is power density measured in watts per gallon or watts per cubic foot volume rather than weight. • Volumetric Energy Density—Ditto here. This is energy density measured in watt hours per gallon or watt-hours per cubic foot—again volume rather than weight. You will find these useful both for this section’s comparisons as well as those made in the “Future Batteries” section. Now let’s look at the winning batteries.
Five Trojan Battery Solutions The Trojan Battery Company has been innovating golf cart battery solutions since the 1950s; their appearance here should not surprise you. Electrical vehicle batteries today are substantially superior to those of only a decade ago. You can pick from 6-volt or 12volt solutions, and the distribution network has evolved to give you more service at better prices. We’re going to look at three 6-volt and two 12-volt alternatives from Trojan. The Trojan T-125 model—one of the 6-volt alternatives—is shown in Figure 8-4. Notice its
Figure 8-4 Trojan T-125 6-volt deep-cycle batter y.