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Chapter 8: Batteries 195only kind of water you ever want to put in your batteries. Just cover the plates;don’t overfill the cells till the electrolyte overflows the battery top and causes amess. Ideally, you want a tube from your water jug, or a small cup or glass witha pouring spout, or a clean funnel—something that makes it easy for you to pourwithout spilling. If any electrolyte is spilled, clean it up immediately andneutralize the spill area and its surroundings with baking soda per the nextsection’s instructions. Remember that the battery electrolyte is a strong acid thateats metal, upholstery, clothing, shoes, and people without discrimination.• Corrosion and Tightness—Make a visual inspection of your batteries, thebattery connections, and the battery compartment. Look at, touch, and pull onthings. The battery tops (and anything else in the battery compartment) shouldbe kept clean of dust, dirt, corrosion, and splashed battery acid. Nip any one ofthese in the bud immediately. An old toothbrush and a box of baking soda workwonders. Use a solution comprising two tablespoons of baking soda added to asmall glass of water (one pound per gallon is the ratio), applied to the batterytops and terminals. Never use it in the battery cells—be sure to keep themtightly capped during cleaning. Diligence with baking soda and toothbrushwill neutralize any acid and keep the batteries clean. Touch and pull to checkthat none of your electrical connections have worked loose. Tighten any looseconnections immediately.• Measurement—Use a digital voltmeter or hydrometer to give you a readout ofthe battery state-of-charge. Remember to monitor your batteries in a “rested”condition, and try to shoot for the same rest period in all your measurements,or make a note of any discrepancies.Today’s Best Battery SolutionYou already know this book recommends lead-acid batteries as the best solution fortoday’s EV converters. You also know what type of lead-acid battery to buy and a lotabout its characteristics. Your choice is made even easier because there are only a certainnumber of battery vendors in your immediate geographic area to choose among. Unlikebuying motors, controllers, and other parts, you’re not likely to be ordering yourbatteries by mail. Your choice basically comes down to who offers the best price on thebatteries you want, and what capacity, rating, voltage, size, and weight you need.In a slight departure from the previous chapters, we’re going to recommend onemanufacturer, then look at several alternative offerings from their line to give you theflavor of the real choices you will encounter. The batteries recommended are from theTrojan Battery Company of Santa Fe Springs, California. As with the motors andcontrollers, don’t read anything important into their appearance here. They are onlyone of a large number of battery manufacturers. A list of battery manufacturers appearsin Chapter 12, but in this case, which battery distributors are operating in yourgeographic area is the more important factor.Before getting into the actual batteries, let’s add a few more definitions to youralready expanded battery vocabulary:• Power Density (Orgravimetric Power Density)—Also known as speck power,this is the amount of power available from a battery at any time (under optimalconditions), measured in watts per pound of battery weight. It translates directly