Why Won’t My Lawnmower Battery Stay Charged? Expert’s Interview


Cranking your lawnmower is not possible with the battery as it provides the power to start the engine. Once you start the mower, the alternator will handle the electric system and recharge the battery. When your lawnmower battery doesn’t stay charged, there might be some issue with the battery.

Why won’t my lawnmower battery stay charged?

If the lawnmower battery failed to hold the charge, an issue might have already occurred in the charging system, stopping the battery from being recharged. Or, the battery is draining its power while the mower engine is off.

Why Won’t My Lawnmower Battery Stay Charged?

When you are wondering why won’t your lawnmower battery stay charged, it is essential to figure out the issue first. Unless you discover the problem, you can’t solve it. That’s why here we are mentioning some possible reasons for this issue.

1. Dysfunctional Alternator

Why Won't My Lawnmower Battery Stay Charged - Dysfunctional Alternator

An alternator plays the primary role of recharging the mower battery while running on the machine. If it is not working appropriately, the battery may not be charged.

If your mower engine dies after running for a while, the problem could be associated with the dysfunctional alternator.

Another way to discover the issue is to notice the accessories run by the electric system.

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If the headlamps lose their brightness within a few minutes of operation or the horn sound decreases gradually, a lousy alternator might be the main culprit.

2. Bad Cell

Nothing lasts forever. After a particular time, your lawnmower batteries need to be replaced.

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So how do you find out the best time to buy a new battery? The battery will create a bad cell, meaning the charging cycle will reduce gradually.

Moderate temperatures are perfect for batteries; they can withstand neither excessive heat nor cold.

3. Cables Corroding In Batteries

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It is possible corrosion occurs in cables and other electrical contacts of batteries. When corrosion develops in these parts, the alternator cannot make a solid connection with the battery.

As a result, batteries may not have sufficient charge to support the machine to start. Keeping your battery maintained helps stop this from occurring.

4. Reduced Water Level

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Most modern batteries don’t have any holes, which contain water. So they are almost maintenance-free.

However, some exceptional batteries are there, which have to fill holes. Their battery performance may fall if the water level reduces. In that case, you want to fill the hole with water thoroughly.

5. Loose Or Bad Alternator Belt

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With a loose or too old alternator belt, an alternator may not function appropriately. There is a possibility that the alternator will not produce sufficient electricity to recharge the battery.

6. Unnecessary Battery Drainage

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If both battery and alternator don’t have any issue, then the problem could be related to unnecessary battery drainage.

A simple example might be keeping the headlamp on or using a power outlet with an “always-on” function while you are not using the machine.

Read More – Why Is My Lawnmower Battery Dying? How To Fix It?

How To Maximize Lawnmower Battery Performance?

How To Maximize Lawnmower Battery Performance?

You have already learned about this question: why won’t my lawnmower battery stay charged? Now, it is time to know how to keep your lawnmower battery healthy and maximize its performance.

Here we are mentioning few pro tips to keep your lawnmower battery in good condition.

Serial No. Tips To Maximize Lawnmower Battery Performance
1 Monitor your batteries regularly to determine if there has been a change.
2 During the off-season, run the mower for a few minutes for better run-on.
3 After using the lawnmower, don’t forget to turn off all switches of the machine.
4 Occasionally, use a smart charger to recharge the battery to see charge holding capacity.
5 Check out whether the battery wires and other parts are correctly fastened.
6 Keep your lawnmower at a favorable temperature to prevent battery damage.
7 Clean the internal parts of mowers regularly to prevent grease build-up.

What Charges A Battery On A Lawnmower?

Charges are required to start a lawnmower battery. If the lawnmower battery doesn’t have any charge, you will struggle to start the engine.

Why Won't My Lawnmower Battery Stay Charged - Dysfunctional Alternator

What charges a battery on a lawnmower?

Alternators charge a battery on a lawnmower. Most new lawnmowers have alternators, which have the battery to charge. Each lawnmower has two alternators: one provides voltage for horn and lights, and another enables the battery to be charged.

In addition, the red wire from the charging lawnmower is connected in series with a diode that charges the battery.

So, by converting mechanical force into electrical energy, alternators transmit power to the battery. Hopefully, you have learned the answer to this question: what charges a battery on a lawnmower?

Why Do Lawnmower Batteries Not Last?

No one can deny lawnmowers will not last a lifetime. However, you also don’t want to neglect the maintenance for a better lifespan. The better care you take, the possible extended time it will last.

Why do lawnmower batteries not last?

Generally, a lawnmower lasts up to 5 years, and after that, you want to replace it. If your lawnmower battery dies too early, a wide range of reasons can cause cars batteries to fail.

Here are a few possible reasons why do lawnmowers not last:

  1. You are exposing the engine to harsh weather conditions like excessively hot or cold climates.
  2. You are not using the lawnmower for a long time.
  3. Lawnmower batteries may not last if there is an electrical system issue or typical user error.
  4. You have kept the lawnmower battery in poor or weak conditions.
  5. There could be any faulty charging system for the lawnmower.

How Do I Know If My Lawnmower Battery Is Bad?

It is true that you need to replace your too old lawnmower battery to ensure 100% machine efficiency. You can operate your mower efficiently with a bad lawnmower.

How do I know if my lawnmower battery is bad?

Your lawnmower battery will show different warning signs when it is terrible, such as

  1. It has become already too old
  2. It takes time to start
  3. You often need a long crank to start the lawnmower engine
  4. The lights and horn are working, but the engine is not starting
  5. It stops at the middle of the mowing
  6. The mower makes a fast clicking sound

So, these are possible scenarios for this question: how do I know if my lawnmower battery is bad?

How Do I Test My Lawnmower Battery?

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If you are confused about whether your lawnmower battery is okay or not, you can test the battery using a digital multimeter.

How do I test my lawnmower battery?

A lawnmower battery comes with different bolts such as 36-V, 24-V, or even 12-V. While testing the battery voltage, the reading should be equal or almost equal. When the result is far below equal, it is better to replace it.

With a 12-volt battery, if the multimeter displays a reading below 10.5 volts, it appears that the battery has insufficient voltage and replacement is necessary.

If the reading is equal to or more vaults for 36-V and 24-V, you don’t need to replace the battery as long as it doesn’t show any issues. So, in the following way, you can test the battery health of your lawnmower.

Will A Bad Solenoid Drain Battery On A Lawnmower?

Will A Bad Solenoid Drain Battery On A Lawnmower?

There could be many reasons behind a bad starter solenoid, such as rapid clicking sounds, no clicking noise, no crank of the engine, etc.

Will a bad solenoid drain battery on a lawnmower?

Probably not. Bad solenoids cannot drain lawnmower batteries. This component only does a primary task: connecting the battery to the starter and help to start the engine. If your lawnmower battery is draining, the battery might have become too bad or too old.

So, a bad solenoid has no connection to this question: will a bad solenoid drain battery on a lawnmower?

How Long Does It Take To Charge A Dead Lawnmower Battery?

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The charging time for a new lawnmower battery and an old lawnmower battery will not be equal. It will take longer for the lawnmower battery to get fully charged as it becomes older. In addition, older batteries can hold the charge as long as newer batteries do.

How long does it take to charge a dead lawnmower battery?

One hour is enough to fully charge your deal lawnmower battery with a standard 10-amp charger. But if the charger has lower output, fully recharging the battery will take more than one hour. For fast charge, you want to choose a smart charger with high output.

However, you should remember that too fast charging(less than one hour) may drain the battery quickly. Hopefully, you have learned — how long does it take to charge a dead lawnmower battery?

Final Thought

A healthy lawnmower battery will ensure you start the machine smoothly as long as the other parts are entirely okay.

Any problems with the battery of your lawnmower need to be addressed immediately. After all, you don’t want engine inefficiency and take any hassle while running the mower.

That’s why we have discussed every possible reason for this question: why won’t my lawnmower battery stay charged? Thanks for reading the whole article —let us know the type of battery issue you are facing. Drop a comment on which kind of battery issue you are facing; we will try to solve it.

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Why My Lawn Mower Stops Running After A While? Expert’s Interview

Last update on 2021-09-30 / Affiliate links / Images from Amazon Product Advertising API