7 3/8 x 9 1/4 T echnical / Build Your Own Electric Vehicle / Leitman / 373-2 / Chapter 9
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Build Your Own Elec tric Vehicle
Figure 9-2 Graphic summar y of batter y discharging and charging cycles.
The Ideal Battery Charger Battery charging is the reverse of discharging, but the rate at which you do it is critical in determining its lifetime. The basic rule is: Charge it as soon as it’s empty, and fill it all the way up. The charging rate rule is: Charge it slower at the beginning and end of the charging cycle (below 20 percent and above 90 percent). When a lead-acid battery is either almost empty or almost full, its ability to store energy is reduced due to changes in the cell’s internal resistance. Attempting to charge
