Selecting the right trolling motor battery for your motor is as important as selecting the right trolling motor for your boat. All batteries are not created equal, so it is imperative that you choose your new trolling motor battery wisely.
Never attempt to save a few dollars by using a car battery in place of a deep cycle battery or you will eventually find yourself up a creek without a paddle. A trolling motor uses a Deep Cycle Battery, which is very different from the standard lead-acid battery that you would use to start your automobile. The deep cycle battery is designed to be totally discharged repeatedly, and then completely recharged again. If you were to completely discharge your car’s battery, it would very likely never regain it’s full potential ever again.
Although price is usually a primary factor in selecting a new trolling motor battery, it should not be the deciding factor. There are a number of things that you must consider before selecting your new battery. You can usually replace the original trolling motor battery with a new “identical” model, but if you have added any new electrical equipment or accessories to the boat, then you may have to look at a different model battery to handle this extra load.
The typical 12 volt system normally requires at least 1.2 amps of current for every pound of thrust that your trolling motor produces, so you will need to know the output thrust of your motor and then add to that the current draw from any accessories that the battery will have to provide power to as well.
Remember to always charge your depleted batteries soon after using them. If you wait even a few days to recharge them you can diminish the amount of charge that the battery can hold and shorten the useful life of the battery. Use a battery charger designed for deep cycle batteries, and do not use a trickle charger on your deep cycle battery. The correct charger for your trolling motor battery will regulate both current and voltage and will taper off the charge as your battery becomes fully charged.
Check the water level in your battery and if it is low, always use distilled water to top it off. If your battery is constantly low on water, you should put a voltmeter on the battery as it charges to verify that the charger is supplying no more than 14 1/2 Volts.