In Brief: How to Charge a Lawn Mower Battery
Open the front cover or lift up the mower seat to access the battery. Disconnect and remove it from the mower. Attach the positive charge cable to the positive battery port and the negative charge cable to the negative port. Plug in the charger and allow a few hours to charge fully. Replace and reconnect the battery.
Lawn mower batteries can drain just like any other battery. If you leave your mower in storage over the winter, the battery might be dead when you go to start it for your first mow in the spring.
Sometimes batteries also die if you leave the ignition switch on (for a riding mower) or the battery is old and constantly discharging.
Whatever kind of lawn mower you have, the battery is chargeable. Learn how to charge a lawn mower battery so you can get your mower up and running again.
How to Charge a Lawn Mower Battery: Detailed Answer
This is a simple method for charging a riding lawn mower battery. Walking mowers with batteries will have a similar process for charging with the only exception being battery location.
- Step 1: Accessing the Battery
Lawn mower batteries are often located either under the seat or directly under the hood. Check each place to see where your battery is located. If you don’t find it there, refer to your owner’s manual.
It’s possible to charge the battery while it’s still connected to the mower. However, removing the battery before charging it is safer. To remove the battery, unscrew the clamps on the negative side of the battery, followed by the positive side, then pull the battery out.
Place the battery somewhere clean and open. Check the access ports for corrosion. If the battery is older, check the battery acid levels. If there is any noticeable damage to the battery, it may be better to replace it rather than charging it. - Step 2: Prepping & Charging
Charging a lawn mower battery requires a special type of charger. Lawn mower batteries are generally between 6 – 12 volts. Any charger you use must be appropriate for the size of battery you have, and it must be able to charge at 10 amps or less.
Charging a lawn mower battery with a charger giving off more than 10 amps can damage the battery.
When your battery is ready to charge, you can do one of two things. You can either charge it slowly for a full charge or perform a quick jump start.
Slow Charge
This is the recommended method for charging a lawn mower battery. Charging slowly allows you to get a reliably full charge.
Start with your battery on a clear space. Adjust the settings on the charger to match the needs of the battery, if applicable. Make sure the charger is distributing at 10 amps or less.
Take the battery charger and connect the negative charge cable to the negative access port, then connect the positive charge cable to the positive access port.
Pay close attention to where you’re connecting the cables so you don’t get this part wrong. Each cable and port should be clearly labeled with a plus or minus sign.
Once the charging cables are connected, plug in the charger. Most 10 amp chargers can recharge a mower battery within around an hour. Older chargers or those operating at less than 10 amps may take longer, up to around eight hours.
When the battery is sufficiently charged, unplug the charger from the outlet. Disconnect the positive charge cable from the positive battery port first, then disconnect the negative charge cable from the negative port.
Jump Start
The other method you can use is for times when you need to start and use the mower right away. By jump starting the mower, you can get enough charge into the battery to turn it on. Jump starting helps most if the mower battery died from being drained accidentally.
To jumpstart the battery, leave it connected to the mower rather than removing it. Attach the positive jumper cable end to the positive battery port and the negative jumper cable end to the negative battery port.
Then, do the same on the battery you’re using to charge the mower.
Car batteries are the most commonly used batteries for jump starts. However, modern battery chargers can also be used to jumpstart a mower.
Turn on the car, vehicle, or charger you’re using to jump start your mower. Wait for a few seconds before then starting the mower itself.
Note: Jump starting is a temporary solution. If a battery is old or failing, jump starting it will not help it to retain a charge. This method only helps if you need to use your battery immediately. - Step 3: Finishing
If you removed the battery to charge it, replace the battery back into your mower. Attach the positive connection first, followed by the negative connection. Secure it in place and close the hood or mower seat.
If you charged the battery without removing it, by slow charging or jump starting, make sure the connection points are firmly attached to the battery. Then, close the hood or lower the mower seat. You can do this when the mower is on or off.
Watch the full process of charging a lawn mower battery:
Conclusion
Lawn mower batteries are able to lose charge just like any other batteries. Learn how to charge a lawn mower battery so you can get back to mowing as quickly as possible if your battery dies.