How Long Does a Lawn Mower Battery Last: A Helpful Guide

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A lawn mower is a piece of important equipment needed to keep your grass green, short, and healthy. Luckily, a lawn mower isn’t hard to maintain as long as you use and store it properly. If your machine stops working out of the blue, it could be an issue with the battery.

Now, you might be wondering, “How long does a lawn mower battery last?” Keep reading to find out. We’ll also share with you some tips to keep the batteries of your mower in good condition.

How Long Does a Lawn Mower Battery Last?

Throughout the years, lawn mower manufacturers have developed so many innovations that make mowing lawns a lot easier. One of which is the integration of a battery system which has eliminated the need for a pull-cord-style starter.

Today, most lawn mowers have a push-start button that quickly gets you into the task. Many models even come with alternators and voltage regulators that keep the battery juiced up.

Like most batteries, though, you can only use lawn mower batteries for a certain period. Typically, the average lifespan of a 12-volt lawnmower battery is three to five years. It can be charged about 500 times and delivers about 45 minutes to one hour of runtime per charge.

Factors Affecting Lawn Mower Battery Life

Now that you know the answer to the question “How long does a lawn mower battery last?”, it’s time to dig deeper into how to preserve the battery life of your mower. Several factors affect how long the battery in your lawn mower will last, including:

Battery Type

Lawn mowers typically use either lead-acid batteries or lithium batteries.

  • Lead-Acid Type Batteries

A lead-acid battery is a technology roughly a century old. This type of battery has lead plates immersed in an acid electrolyte.

The plates get covered with sulfate every time the battery discharges, turning the acid into alkaline. The plates return to the acid electrolyte as the battery is charged back up.

Over time, the antimony and acid content of the battery results in corrosion issues. Thus, they have a shorter lifespan and require regular maintenance to keep them running properly.

Another problem with these types of batteries is that they can’t go to their full capacity once discharged.

Generally, these batteries can last from one to three years or after 200 to 300 charges. For these reasons, many lawn mower manufacturers switch from acid batteries to lithium-ion batteries.

  • Lithium Ion Batteries (Li-ion)

Lithium batteries are maintenance-free. They also have a longer lifespan, ranging from three to five years or 500 charging cycles.

Moreover, the Lithium-Ion battery life depends on the material used to manufacture it. A high-quality material gives properties like prolonged battery life, more energy storage, and fast charging qualities.

learn how long does a lawn mower battery last

Corroded Battery Connections

All battery systems rely on solid connections for them to work properly. Corrosion is one of the most common issues with lawn mower batteries, especially for models that use a lead-acid battery.

As explained earlier, the acid content of the battery can eventually lead to corrosion. If you find a corroded connection in the battery system of your machine, you need to disconnect the battery cable.

You can clean cables and connections using baking soda and water. Additionally, you must seal the battery terminals with anti-corrosion gel to prevent corrosion build-up.

Faulty Charging System

Another possible reason for issues with lawn mower batteries is the faulty charging system.

Depending on the size of your lawn mower, your equipment can have an alternator, like the ones in your car, or an internal one under the flywheel.

Most residential lawn mowers have an internal alternator. But how do you know if you have a faulty charging system?

Using a volt-ohms meter, you can test if the charging system works.

  1. With the engine turned off, touch the leads to the battery and take note of the number registered on your volt-ohms meter. 
  2. Next, run your mower about 4/4 throttle and recheck the meter reading.

If the reading is higher than the initial reading taken, then it means that the alternator is charging the battery. If the reading hasn’t changed, you have an issue with your mower’s charging system.

How to Care for and Maintain Lawn Mower Batteries

There are several steps you can do to increase the battery life of your lawn mower, such as:

1. Fully Charge Your Lawn Mower Battery Before Use

Most lawn mowers come with a battery charger. While it won’t affect the performance of your equipment, not fully charging your lawn mower can improve your battery’s health.

2. Don’t Run It Very Low

There’s an ongoing debate about whether or not you should let batteries drain completely before charging.

Well, it’s important not to discharge it all the way. That means keeping the battery charge level at 20 percent or higher.

Discharging it below that rate will accelerate the battery’s degradation. The best action is to follow the manufacturer’s instructions on battery charging.

Manufacturers’ advice differs depending on the battery type, battery chemistry, and use.

3. Perform Routine Maintenance

While electric mowers are essentially maintenance-free, here are simple maintenance practices that can keep their batteries in top condition, such as:

  • Remove the battery when storing your lawn mower.
  • Monitor your battery’s performance.
  • Stop use when the battery is overheated.

4. Avoid Mowing Too Early in the Morning

Wait for the grass to dry up before mowing if you really want or need to mow early in the morning. That’s because wet grass will cause the lawn mower to work harder, consuming more energy. Definitely, it can put a toll on the battery of your equipment. Additionally, raise the mower height.

The higher the grass, the less moisture will be in the lawn mower. Low moisture levels will not cause your motor to work harder, so your batteries are less likely to experience more drain.

Always Have a Well-Functioning Battery

A lawn mower’s battery lifespan is generally three to five years. To preserve its life, follow the tips and suggestions mentioned above.

Should you need to replace the battery, make sure to buy a high-quality replacement for the best possible outcome.

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