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A Guide To Winter Lawn Mower Battery Care

Lawn mowers have smaller-sized batteries. These batteries are crucial for the proper function of your riding lawn mower and walk-behind mowers with an electric start. However, in the winter, when the lawn mower is most often stored for long periods of time, the cold temperatures can damage and even ruin batteries.

Taking care of a lawn mower battery for the winter months requires protecting the battery from cold or moisture. Great options for lawn mower battery care in the winter include:

  • Covering
  • Storing
  • Packaging
  • Removing the battery from its equipment

Lawn mower batteries are an expensive and vital performance component of any lawn mower. The last thing you want is a fairly new battery dying or becoming ruined in the winter months because you forgot or did not know how to take care of it. Read on to find out more about lawn mower battery care for the winter.

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.

Can Lawn Mower Batteries Freeze?

Batteries contain a large amount of liquid chemical material within their metal walls. This material helps with the conductivity of the electrical process that the battery creates.

This liquid chemical material is usually very resistant to freezing. However, in certain circumstances and at very low temperatures, a lawn mower battery can freeze.

Lawn mower batteries can freeze when they are not fully charged or are stored in extreme cold temperatures during the winter months. A half charged battery will freeze into a block of ice at -10 degrees Fahrenheit, which is incredibly cold and not very likely for most inhabited places on Earth.

However, batteries with less charge are much more susceptible to having their liquid chemical interior freezing into a block of ice. For example, a battery that is only charged halfway will turn into a block of ice overnight in conditions that are -10 degrees Fahrenheit.

The condition of the battery and how much charge it is currently holding are incredibly important deciding factors as to whether a battery will freeze or not and at which temperature the liquid within its walls becomes ice.

The following chart shows the common temperatures that freeze lawn mower batteries based on how much charge they have left in them if left overnight.

Battery charge12-volt batteries6-volt batteriesBattery Freezing Temperature
100%12.78 V6.39 V-80 degrees Fahrenheit
92%12.66 V6.33 V-71.3 degrees Fahrenheit
85%12.57 V6.28 V-62 degrees Fahrenheit
62%12.27 V6.13 V-16 degrees Fahrenheit
50%-10 degrees Fahrenheit
40%11.97 V5.98 V+5 degrees Fahrenheit
20%11.67 V5.84 V+19 degrees Fahrenheit
Zero charge+20 degrees Fahrenheit

How To Care for Lawn Mower Batteries in the Winter

Since the battery in your lawn mower is susceptible to damage and freezing during the winter, it is vital that you take care of it properly. A frozen battery is not likely to be charged again.

Batteries that have frozen are more likely to die and not charge fully and should get replaced. It is best not to let your lawn mower batteries get frozen in the first place.

The best way of taking care of a lawn mower battery during the cold and freezing winter months is by removing it. Removing a battery from your lawn mower may seem like overkill or too much preparation. However, removing and storing a lawn mower battery properly could save the battery from being ruined.

Disconnect the Lawn Mower Battery

Even if you have never done it before, disconnecting and removing the lawn mower battery is fairly simple. Make sure that you take the safety precautions seriously and follow the steps listed below to properly and carefully remove the lawn mower battery from its holding case in the body of your lawn mower.

Before starting, you will need the following tools and safety equipment:

  • A clean cloth
  • A metal brush
  • A phillips-head or flat-head screwdriver
  • A solution of water and vinegar
  • Needle nose head pliers
  • Rubber gloves
  • Safety glasses (in case battery is corroded or explodes)
  • Soft cotton Q-Tips

After you have assembled the safety equipment and tools needed, it is time to remove the lawn mower battery.

  • First, make sure that you put the rubber-coated work gloves on so that the battery will not accidentally shock your fingers. Also, put the safety glasses on to protect your eyes.
  • Next, open up the body cavity of the lawn mower. If you have a riding mower, the battery is most likely under the hood or seat. A walk/push mower probably has a battery with visible terminals.
  • Determine which screwdriver is needed for the job and use it to loosen the terminal clamps. There may be one or two screws on each of the terminal clamps.
  • Starting with the negative cable and clamp (it will have a negative sign on it), remove the clamp from the battery terminal.
  • Next, take off the other clamp from the battery terminal.
  • Using a baking soda and water solution (more on this a little later) and the Q-tips or metal brush, clean up the connection points of the battery. There will probably be some corrosion around the terminals.
  • Use the clean cloth to wipe away any debris and moisture from the battery.
  • Finally, gently lift the battery out of its casing from the lawn mower and place it in a cool, dry place.

Removing the battery is not the only way of protecting your lawn mower battery for the winter. You also need a good storage place.

Keep the Battery Clean

Keeping your battery clean is a crucial part of caring for the lawn mower battery in the winter. The most critical point for cleaning a lawn mower battery is any exposed parts and the battery terminals.

Over time, dirt builds up around the battery and should be cleaned off. Also, the terminals may get corroded. Corrosion is especially bad during cold and wet winter months and gets even worse when the lawn mower battery has a build-up of dirt and grime on the walls and terminals.

Terminals on a battery are the most sensitive part for weathering and dirt. The sensitive nature of battery terminals means that cleaning is one of the easiest and most effective ways of prolonging the battery’s:

  • Charge potential
  • Storing ability
  • Overall life

A dirty terminal causes moisture to corrode the metal much more quickly. A quick fix for a dirty battery terminal is cleaning it with a cleaning agent and a wire brush or toothbrush.

  • Create a cleaning agent liquid: The cleaning agent you use could be store-bought and specially formulated for cleaning battery terminals. However, a simple homemade solution of baking soda and water (one part each) is adequate for cleaning the battery terminals.
  • Choose the brush: A wire brush is best for rusted or severely corroded battery terminals. On the other hand, an ordinary toothbrush is capable of removing dirt, grime, and some minor corrosion from the battery terminal.
  • Scrub the terminal: If you’re using a wire brush for cleaning the battery terminal, coat the terminal with a fine mist of the cleaning agent and then scrub around the base and top of the battery terminal. If you are using a toothbrush, dip the bristles of the toothbrush into the cleaning agent and vigorously scrub the outside of the battery terminal.
  • Wipe away the dirt and grime: After successfully scrubbing away the corrosive material and the dirt and grime, use a damp and clean cloth for wiping the terminals clean. Then, use a dry and clean cloth for drying the terminals.

Keeping the walls and terminals of your battery clean not only helps it run better and transmit better energy to your lawn mower, but it also helps protect it while stored during the winter. Cleaning the lawn mower battery before storing it and before using it again in the spring is highly recommended for quality upkeep that gives the battery longevity.

How To Store Lawn Mower Batteries During the Winter

If you leave your battery connected to your lawn mower, a combination of energy drain and long periods of time will ruin your battery. The cold accelerates this process during the winter months. So, it is best if you detach your battery from your lawn mower and store it indoors during the winter when you are not using it.

A cool and dry place indoors is recommended for lawn mower battery storage. Some suitable places of storing a battery indoors where it is protected and out of the way include:

  • Storage closets
  • Crawl spaces
  • Spare bedrooms
  • Armoires

Avoid storing your batteries in places that might get wet and humid, such as:

  • Under sinks
  • In bathrooms
  • In the storage cabinets or shelves of laundry rooms

Humid and wet conditions accelerate corrosion on batteries and could end up harming the battery more than helping it during your winter storage.

You might even consider adding some product to the battery terminals during storage. Some battery terminal products keep them from getting corroded while open to the air and in storage.

Charging Lawn Mower Batteries During the Winter

If you still plan on using your lawn mower during the winter months but still want the battery protected from getting drained of all its power, you should charge the battery while it’s not in use.

Over time, lawn mower batteries lose energy. Since this is accelerated during the cold conditions of the winter months, charging is an excellent idea to ensure it remains fully charged for use.

Charging the lawn mower battery while it is not in use is generally only possible if you store it near an electrical outlet. The battery charger is an adapter that plugs into the electrical outlet in your home or garage and attaches to the battery terminals of your lawn mower battery.

Charging a lawn mower battery during the winter protects it from becoming completely depleted. A completely depleted battery is much more difficult to charge and will not usually have the same length of power or endurance as a battery that has been properly cared for.

When to Charge the Lawn Mower Battery

Charging your lawn mower battery is not always required. However, proper care of the battey on your lawn mower means that you keep it fairly well charged or promptly charge it back to full strength if it becomes dead for any reason, including exposure to cold weather or freezing.

Keep in mind that the higher a battery’s charge, the lower the freezing point is. Charging a lawn mower battery is critical for maintaining the energy levels and for protecting from winter conditions that could freeze the liquid battery components.

Some of the times when you might consider charging your lawn mower battery include:

  • Early spring: After your lawn mower sits during the winter months, it is always a good idea that you hook your lawn mower battery up to a charger and test it. Make sure that the battery is at full strength before starting the first mowing of the spring.
  • During winter: If you plan to use your lawn mower during the cold winter months, it is best to charge the lawn mower battery before each use. Storing your lawn mower in the cold while hooked up to the battery generally drains the battery very quickly.
  • If the battery dies: This seems obvious, but a crucial time for charging the battery is if you find it dead or it dies unexpectedly while mowing. Make sure you give the battery a full charge before starting up your mower again.

How to Charge a Lawn Mower Battery

No matter if you are charging or jumpstarting a completely dead lawn mower battery, the steps are simple and straightforward.

Charging a lawn mower battery requires that you have an energy source like a car battery or an AC electrical outlet. Then, you need a charging station and cables. Finally, you should always wear protective gear before attempting to charge your lawn mower battery.

Here are the steps for charging a lawn mower battery:

  • Put on your safety gear so that your eyes and skin are protected from acid or electrical shock.
  • Get access to the battery and its terminals. You may need the screwdriver to uncover the lawn mower’s body to get access to the battery or battery casing.
  • Leave the battery in its casing with the terminal cables attached.
  • Connect the charging cables starting with the positive cable first (The red one with the plus sign on it)
  • Connect the negative cable next (The black one with the negative sign on it). Remember: Positive cable (Red +) is the last one off and first one on.
  • Make sure that your skin only touches the rubber coating of the charging cables and clamps.
  • Set the charger’s voltage level and amp level to the desired level. The average volt level for lawn mowers is usually 12 volts. More amperage charges the battery faster (Start with two amps and work up to no more than 10 amps).
  • If your charger has a battery charging gauge, keep the charger connected until the battery is fully charged. A 10 amp charger usually takes about one hour for full charging of your lawn mower battery.

Once your lawn mower battery is fully charged with an AC adapter charger, you should be good to go out and use your lawn mower immediately for hours.

Remember that charging your battery occasionally is better than letting the battery drain completely and then charging it from a dead battery. Also, if it dies quickly after you charge your lawn mower battery, it may be time for a replacement.

For a detailed explanation of lawn mower battery charging times read our article, “Lawn Mower Battery Charging Times Explained“.

Best Lawn Mower Chargers

Just because you have a charger cable and charger, it doesn’t mean that it will work for your lawn mower. Lawn mower batteries are smaller than vehicle batteries for cars.

You don’t want to fry the battery, so finding a trickle charger is probably your best bet. Never charge a lawn mower battery with any more than a 10 amp charger.

There are many lawn mower battery chargers on the market. There are some genuinely great products for quick and efficient charging of your lawn mower battery during winter months and when not in use.

Some of the best products for charging the lawn mower battery include:

TOWER TOP 2/10/25a 12V Smart Battery Charger ***Our Top Pick***

This 2, 10, and 25 amp lawn mower battery charger is a great unit that allows you to charge your lawn mower battery at different amperages.

Pros:

  • Has safety protection feature including over voltage, over heat, overtime charging, short circuit, and reverse polarity protection to ensure safety.

LST Trickle Battery Charger

This five-stage automatic charger is capable of trickle charging most dead batteries back to a full charge. The LED indicator makes determining if the battery is charged fully very easy. Also, the cables are protected against reverse polarity, overheating, overcharging, and sparking, making them very safe charging cables.

Pros:

  • Great safety features
  • Trickle charge almost any battery type


Cons:

  • Smaller clamps are more difficult to use and clamp onto terminals
  • Reportedly does not last for much longer than two years of charging consistently

What to Do if Your Lawn Mower Battery is Dead

Leaving your lawn mower battery out in the winter cold will drain it of all energy and result in a dead battery. It is always best if you are proactive and remove, store, and charge your lawn mower battery all winter.

However, if you are left with a dead battery after the long and cold winter months, there are a few things you should do before replacing the battery.

Dead batteries are much more difficult to charge up completely. Because the battery has lost its electrical conductivity, it might never get charged again.

If you find that your lawn mower battery is dead, you should do several things to fix it. You should perform actions on your battery before replacing it include checking connections, charging the battery, and testing the overall battery voltage.

Read more in, “5 Things That Are Draining the Life of Your Lawn Mower Battery“.

Inspect Terminal Connections

The terminal connections are where the battery cables connect the lawn mower to the lawn mower battery. Since your lawn mower is constantly vibrating while running, it is possible that the connections are loose or disconnected from the battery terminals.

Terminal connections might also get exposed to winter weather and moisture that causes corrosion. Although this corrosion can get cleaned with a vinegar and water solution and a wire brush if the damage is too severe, the battery needs replacement.

Loosening connections and damage to the battery are one of the worst downsides to using electric propelled lawn mowers that are dependent on battery power.

Make sure you wear protective equipment and have the proper tools to tighten the terminal screws and clamps back onto the battery terminals. The battery is accessed from under the seat, inside the body of the lawn mower, or should be visible from the outside. There are two terminals that have cables running to them. Check for tightness and connection.

Charge the Battery

As we already detailed before, charging the lawn mower battery might get the power restored. Always make sure that you follow safety procedures and that you buy the correct charger with 10 or less amperage.

The average charging time for a 10-amp charger is about one hour. However, trickle charge units take eight hours or more and will sometimes take all day.

Check the Voltage

Using a multimeter will help you determine the voltage of the battery power on your lawn mower. If you are concerned that the mower’s electricity is too low, make sure that you use the multimeter and set it for DC current testing.

Use the multimeter’s red and black prongs and touch them to the corresponding colors of terminals on the lawn mower battery. The most common type of large tractor or riding lawn mower battery voltage is 12 volts. A fully charged battery will show a reading around 12.7 volts.

When to Replace a Lawn Mower Battery Damaged During Winter

The freezing temperatures of winter wreak havoc on a lawn mower battery. Unfortunately, charging or checking, and cleaning the connections of a battery damaged during the cold of winter will not always bring it back to life. There are certain indications that the lawn mower battery should get replaced, such as:

  • A cracked or leaking battery case: The case that holds the battery’s fluids can sometimes become cracked and leak due to cold winter temperatures. Always check the battery case for cracks or leaks after it has been frozen. The battery acid that leaks out could be harmful or dangerous.
  • A bulged case: Another indication of damage due to winter weather conditions or freezing is a bulged or deformed battery case.
  • Corroded or damaged terminals: Sometimes, the wet weather of winter will corrode the terminals of the battery beyond repair. Replace the lawn mower battery if the wet winter weather has damaged the terminals in any way.
  • Your battery doesn’t hold a charge: After the winter months, you should probably charge the battery for your lawn mower. However, it may be time for a new lawn mower battery if it won’t hold a charge even after a charging session.
  • Loose or broken cables: The cables connecting the battery terminals to the rest of the lawn mower need excellent conductivity and connection. If they are constantly loose or visibly broken, they need replacement and may have damaged the battery. If the battery is also damaged, replace both the battery and cables.

In Conclusion

Your lawn mower is a powerful machine that requires some constant care. The battery power is the main component that keeps your lawn mower working correctly.

One of the most vulnerable times for your lawn mower battery is during the cold, sometimes freezing, winter months.

If you follow the simple safety and precaution steps listed in this article, you will know how to take better care of your lawn mower battery in the winter.