Will A Lawnmower Run With a Dead Battery? (Find Out Now!)

Jessica Stone
by Jessica Stone
We’re committed to finding, researching, and recommending the best products. We earn commissions from purchases you make using links in our articles. Learn more here
will a lawnmower run with a dead battery find out now

One of the main advantages to owning a lawnmower is the fact that you don’t have to rely on your own energy to propel the mower. Most modern lawn mowers are wireless, meaning they are outfitted with a lithium battery that must be charged in order to operate the mower. Meanwhile, other lawnmowers, such as riding mowers, have either a gas- or diesel-powered engine and a battery.

Regardless of the type of lawnmower you have, when the battery dies, you won’t be able to operate it. Oftentimes, you can revive a lawnmower battery by charging it for a few hours, otherwise, you’ll need to use a multimeter to determine if it’s actually dead or some part of the electrical system is faulty. You also may be able to get your lawnmower running by jumpstarting it.

It’s always a good idea to keep your lawn mower battery fully charged and in good condition so it’s ready to use when you need it. We’ll walk you through the steps to determine whether or not the battery is dead, as well as how to jump start it and some tips to keep your lawnmower battery running longer.

Do You Need a Mower Repair Service?

Get free, zero-commitment quotes from pro contractors near you.

Will a Lawnmower Run with a Dead Battery?

The purpose of a battery in a lawnmower is to start the engine. If the battery dies, the engine cannot start unless you can jumpstart it. In order for the lawnmower to jump-start, the battery needs to have enough power to provide a good spark to the spark plug. If it doesn’t the engine will run very roughly, or not at all.

When a lawnmower battery dies, your first instinct may be to toss it or recycle it, and purchase a new one. If your battery is old and it seems to have died pretty fast, it may be time for a replacement. However, before replacing it, try to recharge the battery first. Or, if you want to get your lawnmower running faster, you can jump-start it.

Before attempting to jumpstart the battery, you want to determine whether or not it’s actually dead or if there’s some other issue that’s causing the problem. Check this out if your lawnmower runs for 10 minutes then stops.

How to Know When a Lawnmower Battery is Dead

Before you assume that the battery is the issue, you want to rule out any other possibilities first. Checking both the fuel and oil levels are great places to start. Oftentimes, when the battery is the reason a lawnmower won’t start, you will hear a clicking noise when you try to start it up.

The easiest way to ensure that your battery works is to always keep it charged. Consistent charging will keep the battery in good shape and will also mean that you rarely find your lawn mower dead. In fact, maintaining a fully charged lawn mower battery can extend the battery’s life for up to five years.

If you’ve already tried charging the battery for a couple of hours to revive it to no avail, you should test it using a multimeter. Follow these steps to find out if your lawnmower battery is, in fact, dead:

  • Attempt to start your lawnmower. If the engine doesn’t crank, cranks slowly, or makes a clicking sound the battery might be dead.
  • Locate the battery. On riding lawn mowers you’ll usually find it underneath the seat. Give the cables a tug to ensure that they are tight and use a wrench to tighten them if necessary.
  • If the battery is a wet-cell model, use a screwdriver to remove the caps and make sure that the water level is full. If it’s not, fill the cells with distilled water.
  • Test the battery’s voltage by using a multimeter. Set the multimeter to DC and, at the same time, touch the red probe to the battery’s positive terminal and the black probe to the negative terminal. Read the meter.
  • If the voltage is 7 DC volts or higher, your battery is in good condition and something else is causing the problem. A reading that is slightly lower may indicate that the battery is discharged and may revive after charging. Whereas, 11.5 volts or lower means that the battery is likely sulfated and needs to be replaced.

Look at these 5 lawnmower brands to avoid.

How to Jump-Start Lawnmower Battery

Once you’ve determined that the battery is the culprit, you can try jumpstarting it you’re your car by following these steps:

  • Use baking soda and a wire brush to clean any corrosion buildup on the battery terminals of both your car and lawnmower. Corrosion can prevent a proper connection between the cables and the terminals.
  • Connect the red cable to the positive terminal on the lawnmower battery and the other end to the battery in your car. Then, connect the black cable to the car battery first and the other end should be grounded to the lawn mower’s engine block.
  • First, start your car and then attempt to start the lawnmower. If it doesn’t kick on immediately, let the car engine run a little longer before trying to start the mower again.
  • Once you get the mower started, remove the jumper cables in the reverse order that you placed them. Be especially careful to avoid letting the clamps touch each other until they’re all removed.

Note: Jumping a lawnmower can only be done if the mower has a 12-volt charging system. If you try to jump a 6-volt battery you’ll fry it.

Although jumping may be possible, charging the lawn mower’s battery is always preferable to jump-starting it.

Do You Need a Mower Repair Service?

Get free, zero-commitment quotes from pro contractors near you.

Final Thoughts

Proper lawn mower battery maintenance is an excellent way to ensure that your mower operates at peak performance levels. From making sure the cables are tight and cleaning the battery terminals on a regular basis to making sure the battery is fully charged every couple of months, if you take care of your battery, it will last longer. And if your lawnmower doesn’t start, now you know how to properly troubleshoot the issue, determine if the battery is the culprit, and jumpstart it as needed.

Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

More by Jessica Stone