Why Does My Lawn Mower Battery Keep Dying?

Maybe you just bought your lawn mower, and you’re having battery problems already, or maybe you’ve had the same mower battery for years with no problems until now. But many of us have been there before: you finally have some time and nice weather to get out and mow the lawn, but nothing happens when you go to start your riding mower or push mower.

You charge it up with your fast charger or trickle charger, and the voltmeter is showing that it’s fully charged, but again you get nothing when you re-install it and try to start the mower again.

Your battery keeps dying, and all you can wonder is “why?”

Why lawn mower batteries die

Typically, lead acid lawn mower batteries only last a few years. It’s common for lawn mower owners to purchase and install a new replacement battery every year. Commercial lawn mowers may need their batteries replaced multiple times during the grass cutting season due to heavy use.

This is because there is a constant chemical reaction happening between the acid and the lead, as well as repeated vibrations from the lawn mower engine and the bumps and jostles of the mowing process.

Over time, these factors can lead to the degradation of the acid, the lead plates in the battery cells, and even cracks that reduce a lead acid battery’s ability to generate cold cranking amps and starting power. It can also result in a battery that can’t hold its charge.

If you have a maintenance free battery, and it’s over two years old, you probably won’t have any luck trying to revive it. You’ll need to replace it, which isn’t a bad thing at all!

Replacement lawn mower batteries

This is the most common fix for a lawn mower battery that keeps dying. Lawn mower batteries are designed to be recyclable and maintenance free these days, so bring your old battery in with you when you buy your replacement so you can exchange it.

Blain’s Farm & Fleet proudly offers a lawn mower battery core exchange service that recycles the lead and plastic components of batteries, while safely disposing of remaining acid.

When you’re looking for a new lawn mower battery, you want to make sure you’re getting a reliable battery with a good warranty. If the battery doesn’t offer at least 1 year of free replacement warranty coverage, then it’s not worth your time.

Different types of lawn mower batteries

Most lawn mower batteries are a group u1 12-volt battery with a CCA rating of 150 – 350 cold cranking amps. Cold cranking amps (CCA) is essentially represents the starting power of the battery. The higher the CCA, the more starting power the battery can deliver.

You can never have too much starting power, so the higher-CCA option is always a good choice.

If you have a lawn tractor or riding lawn mower, you’ll definitely want to get a battery with the most cold cranking amps possible to start the larger engine in your machine.

If the property you’re mowing is bumpy, or if you like to mow at full speed, or just want longer life from your battery, an absorbed glass mat battery may be right for you. AGM batteries are more durable and more efficient because they have a fiberglass material packed in between the lead plates that make up the guts of the battery.

This material helps keep the acid in full contact with the plates at all times for more efficient power, as well as absorbed some of the engine and terrain vibrations, which prolongs battery life.

In rare cases, some mowers and lawn tractors will require a deep cycle battery.

The final thing to consider when replacing your lawn mower battery is the configuration of the positive and negative posts.

If you want to replace your own lawn mower battery, note that the process is incredibly similar to replacing a car battery. It’s often very straightforward to replace a lawn mower battery, and it only requires a few simple tools.

Some lawn mower batteries have the positive terminal on the right side, some have it on the left. This is another way that bringing your old battery into the store can help you. Simply pick the new battery that matches up with your old battery in terms of the post placement before exchanging the old battery to be recycled.

Preventing Your Lawn Mower Battery from Dying in The Future

As a regular part of your winterizing routine, make sure you remove your battery and hook it up to a battery maintainer during the winter months. This will keep the battery charged and fresh for next season.

Winterizing your lawn mower and other power equipment is crucial for achieving a quick and reliable start up after the offseason ends.

Small Engine Service & Repair

If you don’t have the technical know-how, or just don’t have the time to troubleshoot and repair your lawn mower yourself, give Blain’s Farm & Fleet a call. We employ factory-trained professional small engine mechanics at our stores to provide you with excellent and speedy service on your lawn and garden equipment.

Sometimes, trying to get your mower running can feel like you’re beating your head against a wall, so let our small engine repair & parts department take care of it. Any maintenance and repairs will be done faster and done right the first time, so you can spend more time getting things done.