Lawn Mower Battery Guide: Types, Troubleshooting & Maintenance
- by Joe Weber - updated on 6/20/2025
Is your lawn mower ready for the mowing season? One crucial component to check is your lawn mower battery. Riding lawn mower batteries typically last about 3 to 5 years, but a lack of maintenance can shorten their lifespan. If your mower is slow to start (or won't start at all), chances are the battery is to blame.
This guide will walk you through everything you need to know about lawn mower batteries, including:
- The different types available
- How to choose the right replacement
- Troubleshooting tips
- Essential battery maintenance advice
Let's get your mower powered up and ready to go.
What Types of Riding Lawn Mower Batteries Are There?
Lead-Acid Batteries
- Most gas-powered riding mowers use lead-acid batteries
- Available in flooded (wet cell) and AGM (sealed) types
- Affordable, reliable, but heavier and require more maintenance
Lithium-Ion Batteries
- Common in newer electric and cordless mowers
- Lightweight, maintenance-free, and long-lasting
- More expensive and require a compatible charger
Pro Tip: Stick with the type your mower was designed for to avoid compatibility issues. Lithium batteries for lawn mowers are designed to work with specific models.
How Do I Choose the Right Lawn Mower Battery?
Not all mower batteries are created equal. Selecting the right battery for your lawn mower means understanding your mower's specifications and how different battery types, sizes, and features can impact performance.
Voltage (6V vs. 12V)
- Most riding mowers use 12V batteries
- Some older or smaller models may use 6V
Battery Chemistry
- Match the chemistry: lead-acid with lead-acid, lithium with lithium
Size & Terminal Position
- Check BCI Group Size, usually U1, U1L, or U1R
- U1L = Positive terminal left, U1R = Positive terminal right
Cold Cranking Amps (CCA)
- CCA range for mowers: 150–300 CCA
- Higher CCA = Better starts, especially in cooler temps
Quality & Warranty
- Stick with trusted brands like Duracell Ultra
- Look for warranties of at least 6 months
Pro Tip: Not sure which one you need? Bring your battery to a Batteries Plus store and get expert help.
How Do I Troubleshoot A Dead Lawn Mower Battery?
When your mower won't start, it doesn't always mean the battery is completely dead. Sometimes, a quick fix is all it takes. Here are the most common steps to troubleshoot and resolve battery-related starting issues.
1. Try Charging the Battery
- Use a compatible charger (12V for most mowers)
- The X2Power 1.5 Amp charger is a great pick
2. Check Fuel and Oil
- Make sure the mower has gas and proper oil levels
3. Clean the Terminals
- Notice any corrosion? Clean with baking soda or a terminal cleaner and a wire brush
- Always disconnect the negative (-) terminal first
4. Listen for Clicks When Starting
- Rapid clicking = Weak battery
5. Test Battery Voltage
- Healthy battery = Around 12.6V
- Less than 12.2V = Likely needs replacement
6. Rule Out Other Issues
- Starter motor, solenoid, or fuse could also be the problem
Free Battery Testing: Stop by your local Batteries Plus and let us test your battery at no charge.
What Are Lawn Mower Battery Maintenance Tips?
A well-maintained battery is the key to dependable performance and long life. These simple upkeep habits can help you avoid early battery failure and ensure your mower is always ready when you need it.
Keep It Charged
- Charge every 4-6 weeks during storage
- Use a trickle charger or maintainer
Clean Terminals Regularly
- Prevent corrosion with terminal cleaner and protective spray
Pro Tip: The Deka Top and Side Post Battery Terminal Protection Kit comes with everything you need to keep your battery terminals clean: Terminal Cleaner Spray, Terminal Protection Spray, Battery Terminal Protectors, and a Terminal Brush.
Inspect for Damage
- Look for bulges, cracks, or leaks
- Tighten loose connections
Check Electrolyte Levels (if applicable)
- Only for flooded lead-acid batteries
- Add distilled water to cover the plates
Store Smart Over Winter
- Remove and store the battery in a cool, dry location
- Use a maintainer or recharge every 30-60 days
Battery maintainer tip: Keep your battery topped off and healthy during the offseason with a battery maintainer for longer life.
What Are the Signs You Need a New Lawn Mower Battery?
Eventually, even the best-maintained batteries reach the end of their life. Knowing the warning signs can help you replace your battery before it fails when you need it most.
- Hard to start or won't crank: The engine struggles to turn over or won't respond at all when you turn the key. This is often the first and most obvious sign that your battery is failing.
- Loses charge quickly after charging: If your battery won't hold a charge for more than a day or two, even after a full recharge, it's likely losing capacity due to internal wear or sulfation.
- Visible damage or heavy corrosion: Cracked casing, bulging sides, or significant terminal corrosion can all signal that your battery is compromised and may not be safe to use.
- The battery is older than 3–5 years: Even if it seems to work fine, a battery that's reached this age is much more likely to fail unexpectedly. Replacing it proactively can save you trouble later.
Pro Tip: Don't get stuck mid-mow. A new lawn mower battery from Batteries Plus is often a fast, affordable fix.
Why Shop Batteries Plus?
When it's time to replace your lawn mower battery, you want a reliable solution that fits your mower and your schedule. Your local Batteries Plus makes the process simple, fast, and hassle-free.
If you run a lawn care or landscaping business, we've got you covered, too. Our business account services offer volume discounts, flexible billing options, and access to the batteries and chargers your crew needs to stay on schedule.
- Wide selection of lawn mower batteries for all models
- Trusted brands like Duracell Ultra
- Buy Online, Pick Up In-Store available
- Free battery testing and expert help
- Free battery recycling for your old battery
FAQs About Riding Lawn Mower Batteries
How do I know which lawn mower battery I need?
Check your mower's manual or the label on your current battery for details like voltage, group size, and terminal position. You can also bring your old battery into any Batteries Plus store for a free consultation to help you find the perfect match.
How long do lawn mower batteries last?
Most lawn mower batteries will last 3 to 5 years with proper care.
Can I use a car battery in my lawn mower?
No. Car batteries are larger and may damage your mower's electrical system if the voltage doesn't match. They are also much larger and, if not secured correctly, could cause significant damage to your lawn tractor.
Should I disconnect my battery in the winter?
Yes, remove and store it indoors with a maintainer for best results. For more winterization tips, check out or helpful article "How Do I Winterize My Lawn Mower?".
Can I replace a lead-acid battery with lithium?
Only if your mower supports it. Otherwise, stick with the original type. Keep in mind that most conventional riding lawn mowers are designed and built for lead-acid batteries.
What size is a lawn mower battery?
Most use a BCI Group U1 battery, but always double-check your current battery and the lawn mower manual for the recommended battery.
How do I revive a dead lawn mower battery?
Start by using a compatible 12V charger to fully recharge the battery—this can often bring it back to life if it's simply been discharged. Clean the terminals and ensure tight connections. If the battery still won't hold a charge or voltage stays low after charging, it may be sulfated or permanently damaged and should be replaced.