Can I Charge A Lawn Mower Battery With A Car Charger?

Hi there!

Maintaining a properly charged battery is critical for optimum lawn mower performance. When the battery is drained, you need a solution to restore power. 

A frequently asked question is: Can I charge a lawn mower battery with a car charger? Charging a lawn mower with a car charger is a viable option, but you must follow certain precautions and considerations.

This approach provides a convenient and accessible option to restore power to your lawn mower, allowing you to resume your gardening tasks.

So, let’s discover how to do it!

Why Does The Lawn Mower Run Out Of Battery Even When Not In Use?

Your mower runs out of battery while you haven’t used it for a while? So what is the reason?

Self-discharge

This feature makes batteries lose their charge over time. But this rate varies depending on the battery type and lifespan.

Parasitic drain

Electrical components consume a small amount of electricity even when the mower is off. 

These components may include features such as clocks, digital displays, or even faulty wiring. So, this constant power draw can deplete the battery over time.

Extreme temperatures

Batteries are sensitive to extreme temperatures. High temperatures can cause batteries to lose capacity while freezing temperatures damage battery internals.

Can I Charge A Lawn Mower Battery With A Car Charger?

Is It Safe To Charge A Mower With A Car?

The answer is Yes. Car chargers can provide the appropriate charging current and voltage for 12-volt batteries, including lawn mower batteries. 

Yet, please follow the manufacturer’s guidelines and the proper charging procedure.

How To Charge A Lawn Mower Battery With A Car?

Charging a 12 volt lawn mower battery with a car needs the use of a jumper cable and following these steps:

Step 1: Park the car

Park your car close to the mower. We recommend parking behind the mower because the battery is usually under the seat.

Step 2: Prepare the car

Turn off the car, open the hood. Remember to set the brake in this step. In the lawn mower, open the battery compartment and remove any obstacles that might get in the way. Then, lift the plastic caps off the battery terminals in both.

Step 3: Connect the cable

Follow the below order:

  • Attach the red cable to the mower battery’s positive terminal.
  • Connect the other end of the red cable to the car battery’s positive terminal.
  • Attach the black cable to the car battery’s negative terminal.
  • Connect the other end of the black cable to an exposed piece of metal on the lawn mower body (this serves as the grounding point).

Step 4: Start the mower

Note not to start the car at this time. You can leave the battery connected for 1-2 minutes if the mower does not start at first. 

Then try restarting the mower. When the mower is running, you can disconnect the cables.

Step 5: Disconnect the cable

Disconnect cables in reverse order of connection:

  • Remove the black cable from the lawn mower.
  • Disconnect the black cable from the negative terminal of the car battery.
  • Remove the red cable from the positive terminal of the car battery.
  • Disconnect the red cable from the positive terminal of the mower battery.

We recommend handling jumper cables carefully and ensuring that the anode and cathode do not contact each other or any metal surface during the process.

How Long Does It Take To Charge A Mower With A Car?

How Long Does It Take To Charge A Mower With A Car?

It usually takes 30 minutes. But if the mower battery is depleted or severely damaged, it may take longer or not fully charge when using a car.

In such cases, you must consider another charging method or replace the battery if it is no longer charging efficiently.

Is It Safe To Charge A Mower With A Car?

Honestly, it’s not safe. While both use 12-volt batteries, car alternators are designed to provide higher output power than a mower battery can handle. 

Hence, the excess energy generated by a car’s alternator has the potential to damage the mower battery or its electrical components.

Thus, we recommend using a dedicated battery charger specifically designed for lawn mower batteries to ensure proper and safe charging.

Notes When Charging A Mower With A Car Charger

This process is not safe, so you should not be subjective. Instead, keep these tips in mind to protect yourself and your device:

  • Make sure your car is turned off during charging to avoid electrical interference.
  • Wear gloves and goggles to protect yourself from acid spills or accidental exposure.
  • Never stand directly on the battery while charging, as there is a slight risk of hydrogen gas escaping, which can be flammable.

Then, you can ensure a safer charging experience and reduce the risk of accidents or injury.

How Often Should You Charge Your Mower?

How To Charge A Lawn Mower Battery With A Car

Unlike gasoline mowers, electric mowers do not need oil to operate. Instead, they need charging. How often to charge your lawn mower battery depends on various factors such as battery capacity, usage, and storage conditions. We recommend doing this task at least once a month (during the mowing season).

Yet, if you regularly use your lawn mower or encounter difficult mowing conditions, the battery may need to be charged more often.

Besides, if your mower has a self-discharge or parasitic drain rate, it may need to charge more often to maintain optimal battery levels.

Can You Recharge A Dead Mower Battery?

In most cases, you can recharge a dead lawn mower battery. Yet, the success of this process depends on the battery condition.

You can connect it to a suitable charger and let it charge if the reason is long periods of non-use. But it may not be able to charge effectively even after recharging if it is damaged or sulfated.

Click this link to learn about self-propelled mowers!

Conclusion

Can I charge a lawn mower battery with a car charger? The answer is Yes. Charging lawn mower batteries with a car charger is a viable option to restore power to a discharged battery.

Yet, safety is the priority by ensuring the vehicle’s engine is turned off during charging, wearing protective clothing, and avoiding direct contact with the battery. Thank you for reading!

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