Battery Maintenance

Battery Maintenance Information


Batteries give off two explosive gases - hydrogen and oxygen. Consequently, do not smoke or work with open flames around batteries. Change batteries in well vented areas. Avoid contact with highly corrosive battery acid. Wear acid resistant gloves and safety glasses or goggles. Wash off any battery liquid immediately with large quantities of water or neutralize with a baking soda solution. Remove rings, watches and jewelry. The energy in a bank of golf car batteries can melt a ring if you touch the terminals wrong.


Dirt and moisture on the exterior battery surfaces permits current leakage. It is also harder to inspect dirty batteries for damage. While you can use a commercial battery cleaner, a 1/4 cup of baking soda in 1½ gallons of clean water will work as well. Spray the tops and sides, wiring and battery racks with cleaner. Scrub with a bristle brush soaked in the solution. Let solution stand for at least five minutes for neutralization. Rinse with a low-pressure spray of clean water. If any corrosion remains, repeat the process. Make sure caps are on tight so none of the baking soda gets into the battery since even a few drops can decrease the battery's efficiency and decrease its life.


Next check the state of charge using a hydrometer that measures specific gravity and this chart. A hydrometer gives a better indication than measuring voltage with a voltmeter. Make sure that there is sufficient electrolyte in the battery to cover the plates. If not, add water and operate the battery for several hours to properly distribute the water in the electrolyte so you get a true reading. Measure the specific gravity of the electrolyte in each cell. If the specific gravity varies by more than about 0.025 between cells, replace the battery. Use a hydrometer with a built-in thermometer to correct for variations of specific gravity with temperature.

This test does not tell you about the condition of the battery, just the state of charge. A discharged battery should be recharged immediately. Otherwise, sulfating will occur leading to loss of active plate materials and reduced battery capacity. Lead sulfate, a gray material covering the plates, ruins most batteries before their time.

To determine true battery condition, you need a battery load tester that places high amperage load on the batteries to see if it will handle a load. For the deep cycle batteries used in golf cars, first discharge the batteries. This can be done with a discharge machine, if one is available, or by driving the car until the battery is drained. This is different that for a starting/lighting/ignition (SLI) vehicle battery where the load is placed on a fully charged battery since this is the typical operating situation. If the battery voltage drops off significantly while using the load tester, the battery should be replaced.

If one battery in a bank goes bad, it can be replaced with one of like performance and capacity. If more than one battery is bad, the entire bank should be replaced. Typically, a new battery working with old batteries will not give the same life or capacity as if all the batteries were new. That is because the new battery will be quickly brought down to the performance and capacity of the used batteries.

Battery Maintenance Tips

NO: Do not run your car until the batteries are completely dead before you recharge it. Golf car batteries should never be completely discharged prior to charging. This dramatically reduces their service life and will lead to early failure.
YES: At the end of the day, if you've used your car, plug in your charger and let it run until it shuts itself off. Always start each day out with freshly charged batteries.

YES: Add water to your batteries' cells when the electrolyte level gets low.
NO: Never fill up the cells then place the car on charge. The water will expand during charging, come out of the cells and onto the floor.
YES: If you have a low cell or cells, add just enough water to cover the tops of the plates, then charge the car. After the charger has shut off and the batteries are cool, add water to each low cell to the appropriate level, about ½ inch above the plates. Just maintain this level, and remember to:
NO: never fill battery cells to the top.

YES: Periodically wash the tops of the batteries with detergent and water. Then reapply Vaseline or a corrosion stop on all terminals (we sell the corrosion stop). Keeping the tops of your batteries free from dirt, grass clippings and acid residue from charging is one of the most important basic preventive maintenance chores you can perform. Damage from corrosion brought about by the lack of maintenance accounts for the majority of battery/battery terminal failures and vehicle downtime.
NO: Don't deliberately force water into electrical components. Be sure all battery caps are tight.

YES: Disconnect the DC power cord after the car's fully charged and the charger has shut itself off.
NO: Never leave a car unattended with the charger still plugged in for any extended period of time.

NO: Never add acid to a cell. Trying to add acid to a battery with water in the cells is also dangerous. Pouring sulfuric acid into a wet cell can cause the water to react and blow the mixture out and on to you.

Hot summer weather causes golf car batteries to self-discharge at a much higher rate than in cold weather. For example, a healthy, fully charged set of batteries will go from 100% capacity to 50% capacity in just 9 weeks if left sitting idle at a temperature of 86°F. Imagine what happens at 95° or 100°. Batteries are most vulnerable to sulfation when they are sitting idle and partially discharged.

NO: Don't buy the auto parts store brand batteries or you'll be quickly disappointed. They are made differently and will not perform the same as those deep-cycle batteries that are specifically designed for golf cars.