Maybe your lawn mower is brand new and already giving you battery trouble, or maybe you’ve used the same mower battery for years without a problem until now. Either way, few things are more frustrating than finally having time to mow the lawn only to find that your mower will not start.
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?”
A lawn mower battery can keep dying for several reasons. In some cases, the battery is simply at the end of its lifespan. In others, the real problem may be corroded terminals, loose connections, vibration damage, poor off-season storage, or a charging issue somewhere else in the mower’s electrical system.
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!
A full voltage reading does not always mean a healthy battery. A weak battery may still show charge on a voltmeter but fail under load, especially when the starter draws power. Dirty terminals, loose cables, a failing solenoid, or a problem in the mower’s charging system can also keep the mower from starting even when the battery seems charged.
Before replacing the battery, it helps to check for corrosion on the terminals, loose connections, and signs of damage around the cables. These issues are easy to miss and can mimic battery failure.
Replacing the battery is one of the most common fixes when a mower battery keeps dying, especially if the battery is older or repeatedly loses charge after being fully charged.
When shopping for a replacement, look for the correct size, terminal layout, and a warranty that offers reasonable coverage. Bringing your old battery with you can make it easier to match the replacement correctly.
If your store offers battery recycling or core exchange, bring the old battery in when you buy a new one so it can be handled properly.
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.
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.
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.
A lawn mower battery that will not hold a charge does not always mean the battery is the only problem. Checking the condition of the battery, the connections, and your storage habits can make it easier to find the right fix and avoid the same issue next season.
