How to Change a Lawn Mower Battery

All gas-powered lawn mowers run on gas, oil and batteries. Knowing how to change your mower's battery yourself can save you time and money. Unlike many battery-powered devices, however, lawn mower batteries are very specific to the model and type of lawnmower. So, make sure you get the correct battery for your specific model and lawn mower.

Step 1: Find The Battery

Lawn mower batteries are located in one of two places, under the hood, or under the seat of the mower. Most are under the mower. Turn off your mower and remove the keys. Find and release the latch so you can access the battery. Remove any tie-down strap or bar holding the battery in it's holder.

Step 2: Remove Battery Cables

Whenever you remove a battery, begin by removing the black, or ground wire. Reverse this when replacing a battery. If battery connectors are corroded, use a stiff wire brush to brush off the corrosion. If the battery is severely corroded, use a baking soda and water paste and apply it to the terminals. Allow it to sit for a few minutes before using the brush and clear water to rinse off the corrosion. Dry any water with a soft rag.

Be careful not to get the mixture into any battery cells and rinse thoroughly before removing. Baking soda neutralizes battery acid and will neutralize your battery if it gets inside the cells. If the connectors remain tight, use a flat head screwdriver to slowly and carefully pry the connector apart and away from the terminal. Do not force the cable off, you can pop off the connecting terminal. Once the negative (black with negative sign on terminal) cable is removed, then remove the red (positive with plus sign on terminal) cable.

Step 3: Replace The Battery

Once you remove the battery from the holder, clean out (rinse) any corrosion or debris and dry the holder. If the holder is metal and shows signs of rust, sand and paint the rust spots as battery fumes can accelerate rust. Place the new battery back into the holder and attach the tie-down strap or bar. Then attach the positive (red) cable to the positive terminal (plus sign on terminal) and tighten the bolt to secure the cable. Then attach the negative cable to the negative terminal (negative sign on terminal) and tighten the bolt to secure the cable.

Tips for Replacing a Lawn Mower Battery

• Not all batteries are created equal. Make sure you get the right battery for your specific model and type of lawn mower.
• Make sure the power to the mower is turned off and the keys are out of the ignition before removing the battery.
• Remove the negative battery cable first when removing the battery from the lawnmower.
• Attach the positive battery cable first when replacing the battery in the lawn mower.
• Check your battery for corrosion once a month.
• Read your owner's manual to ensure that you are charging your battery correctly and maintaining it properly.