How to Renew a Golf Cart Battery

Like car batteries, golf cart batteries sometimes lose their ability to recharge properly. Most golf cart batteries are of the lead acid type, and when they are discharged too deeply, sulfur from the sulfuric acid solution collects on the battery's lead plates, blocking current flow. This can also happen if the battery drains completely due to being stored for long periods without recharging. Fortunately, there's a simple procedure you can do using a common household chemical, magnesium sulfate (more familiar as Epsom salts), to renew a golf cart battery.

Things You'll Need

• Epsom salts
• Distilled water
• Crescent wrench
• Plastic funnel
• Battery charger
• Drill (for sealed batteries)
• Plugs (for sealed batteries)
• Protective goggles
• Rubber gloves

Instructions

1. Remove the battery from the golf cart, using a crescent wrench to release the power cables. Be sure to wear eye protection and rubber gloves since the sulfuric acid in the battery can cause severe chemical burns. Work in a well-ventilated space and keep open flames away from the battery while you are reconditioning it.

2. Remove the plastic caps on the top of the battery (called "cell caps"). If this is a battery that is sealed (with no cell caps), look closely at the top of the battery to find the access points (these "shadow caps" will be marked). Use a drill to punch through the shadow caps. Once you have the battery open, drain the old water from the battery.

3. Mix Epsom salts with distilled water (use about 8-ounces of Epsom salts per quart. Once the Epsom salts are completely dissolved, use a plastic funnel to pour the solution into each cell of the battery until full. Shake the battery to be sure the solution is well distributed.

4. Charge the battery. For best results, use a multi-phase charger designed for lead acid batteries. This type of charger begins with a high charge rate until the battery is at about 70 percent, then switches automatically to a slower topping charge rate, and finally to a slow trickle charge. This will give you the maximum possible charge and optimize the renewing process.

5. Replace the cell caps once the battery is charged. For sealed batteries, insert plastic plugs in the drill holes (available at auto supply stores). Reinstall the battery in the golf cart, making sure the connector cables are secure. The battery should function normally, although you may need to repeat the charging process a couple of times over the next week to help the magnesium sulfate remove all the sulfur deposits and restore the battery to full charging capacity.

Tips & Warnings

• Unlike cars, golf carts and similar vehicles using lead acid batteries are often stored during an off-season. To prevent a deep discharge due to long periods of non-use, recharge the battery periodically or place it on a trickle charger. Renewing a golf cart battery will work only a few times. When the battery suffers a deep discharge, the sulfur that collects on the lead plates causes permanent corrosion. After about 10 deep discharges, the plates are ruined and the battery can't be restored.

Resources

• Introduction to Lead Acid Batteries
• Tutorial: 6 and 12 Volt Batteries