How Long Does a Lawn Mower Battery Last?

Also known as tractor, a riding lawn mower comes with additional features that are operated with the help of a battery. These range from cranking the engine to power itself to headlights. Considering this, it is difficult to use a riding lawn mower without a battery. So how long does a lawn mower battery last?

A riding lawn mower battery can last between 3 to 5 years. Beyond this, the battery will fail to hold a charge or perform as expected. This means you will have a problem starting your lawn mower after sitting for several hours or the machine stalling during mowing.

Riding lawn mower come with a battery usually located under the seat or the hood. Although rated 12 volts, the battery is usually smaller in size as compared to standard batteries found in automobiles.

Most riding lawn mowers have an alternator that helps in charging the battery while the engine is running. However, after long storage especially during winter, a lawn mower battery will lose it’s charge and there is need to charge it before starting the lawn mower.

How long does a riding lawn mower battery last?

It takes about 3 to 5 years for a riding lawnmower battery to start deteriorating. In this state, the battery will no longer hold charge for longer hours like before. The electrical storage of a lawn mower battery is small and any small decrease in battery power means you will have a problem starting your lawn mower even if it sits for just few hours.

A well-functioning lawn mower battery will hold its charge for up to three weeks when your mower is not in use. There is nothing much you can do about a battery that has reached its shell life. You only need to replace it.

When a riding lawn mower won’t start, a battery is always not the main reason behind that. You also need to check if other components of the engine are working. Ensure there is fuel in the tank, spark plugs are working and the air filters are not clogged.

For cordless electric lawn mowers, the battery will last for at least on hour before need to recharge. These lithium-ion batteries have been enhanced to last for an extended period of time. They can last for more than 5 years while still keeping a strong charge.

Why lawn mower battery keeps dying

Apart from time, there are various reasons your lawn mower battery keeps dying. They include the following:

Extremely cold or hot weather

Extremely cold or hot weather is the main reason why lead acid batteries die. Cold weather slows down important chemical reactions in the battery. Studies have established that at 32°F, a car’s battery loses about 35% of its strength. And at 0°F, it loses up to 60% of its strength.

Hot weather is also a great threat to your lead acid battery. In high temperature, a car battery loses most of its important liquids through evaporation. Hot temperature also accelerates the rate of corrosion. This means your lawn mower battery is not safe in hot summer conditions.

Poor battery maintenance

Just like your lawn mower engine, the battery also needs great care and maintenance to remain in good condition. When you tune up your lawn mower, also remember to check on your battery. Ensure it has enough water, terminals are clean and no liquid or gas is leaking from the battery.

Over time you will notice a powdery substance on the battery terminals. This is a corrosion that forms when cables are loosely connected on the terminals or when leaking gases from the battery are reacting with the terminals.

This usually interfere with the ability of the starter motor to draw current from the battery as well as the ability of the charging system to top the battery off.

A proper battery maintenance involve cleaning its terminals with a solution of baking soda. More so, you need to tighten loose cables on the battery terminals and fix any damage that causing internal gases to escape and react with the terminals.

Components left on

Headlights and other accessories that rely on battery can drain it overnight when left on. Most people forget to completely turn off everything before shutting off the engine. When parking your lawn mower after use, double check everything or disconnect battery cables for longer storage.

Problem in the charging system

An alternator and a voltage regulator are part of the battery charging system in a riding mower. If one of the parts fails, then your battery will not be properly charged. You will have problem starting the lawn mower or using some features.


Overcharging a lawn mower battery means leaving it connected to unregulated charger for too long. This not only weaken the battery’s ability to store charge, there is also a risk of permanent damage to the battery or personal injuries from boiling toxic fumes or battery explosion.

Using a modern charger that shuts off when the battery is fully charged is helpful in preventing a lawn mower battery from overcharging. If the battery is not completely dead, you can also jump start it with a car or another battery.

How to ensure that your battery is lasting longer

The following are helpful tips for elongating your battery’s life.

  • Keep the battery casing and terminals clean. Use a solution of baking soda and wire brush to scrub of any corrosion on the terminals and wipe the casing with soapy solution.
  • Ensure that your battery is getting charged as required. The terminals must be clean and the charging system must be working.
  • Disconnect and remove the battery when storing your lawn mower for longer. This will help the battery conserve the available charge for next use.
  • Use an external charger to recharge the battery after winter before connecting it back on your lawn mower in spring.
  • Replace the battery after its shell life has ended. There is nothing that can revive a battery that has completely died.

Final Thought

A battery is an important part of a riding lawn mower. It would be impossible for some electrical features to function without it. However, there comes a time when your lawn mower battery will expire and you’ll have no other option other than replacing it.

To ensure that your mower battery serves longer without problems, keep it clean, recharge after long storage and avoid leaving electrical components on when parking or storing the mower. New batteries with issues can be taken back to the manufacturer or supplier for replacement as per the warranty.

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