As winter approaches and your lawn mower goes into hibernation, it’s important to think beyond simply stowing the machine in the shed. One of the most critical aspects of winterizing modern lawn mowers is ensuring that the battery is stored properly. Cold weather for a prolonged period of time can be especially harsh on lawn mower batteries, causing issues like chemical degradation and power drain. This can lead to premature wear, reduced capacity, or even complete battery failure by the time spring rolls around.
Importance of Proper Battery Storage
Winter can affect all sorts of power tool batteries. Extended periods of low temperatures can slow down chemical reactions inside the batteries which reduces their charge capacity. In extreme cases, a frozen battery's electrolytes can expand, leading to permanent damage if corrosive materials leak. So proper battery winterization is not just about disappointing dead batteries in the spring, but about mitigating the risks that come with a bad lawn mower battery.
Types of Lawn Mower Batteries
There are primarily two types of batteries used in lawn mowers, each with its own storage requirements:
Lithium-Ion Batteries
Lithium batteries are popular for their lightweight design, fast charging times, and longer life. However, they can be sensitive to extreme temperatures, especially cold. If stored improperly, their performance may degrade over time.
Not all residential electric mowers take weatherization into account, but we'd be remiss to note that the John Deere Z370R Electric ZTrak and new Z380R are two exceptions; the company employs the same technology in its residential mowers as it does agricultural-grade and construction products. (The batteries come with a 5-year/200-hour warranty, which consumers can extend to 10 years/400 hours.)
Lead-Acid Batteries
Lead-acid batteries are typically heavier and more robust but are also more susceptible to cold weather damage. Without proper maintenance and storage, these batteries can lose charge faster, and freezing temperatures can cause the electrolyte to freeze and expand.
Best Tips for Storing Your Lawn Mower Battery for Winter
- Clean the Battery: Before storing, clean the battery terminals and case with a mixture of baking soda and water to remove any corrosion or dirt.
- Charge the Battery: In colder temperatures, lithium-ion batteries should be stored at around 40-60% charge, while lead-acid batteries should be fully charged. A battery maintainer (a type of smart charger) will set the ideal charge level for winterization.
- Remove the Battery: If battery removal is possible, disconnect it from the lawn mower or any other battery-powered equipment to prevent any residual power drain during the winter season.
- Store in a Dry, Cool Place: Choose a dry location with moderate temperatures, ideally between 40°F to 70°F (4°C to 21°C). Avoid areas prone to freezing or extreme humidity, as these can damage the battery.
- Use a Battery Tender: For lead-acid batteries, consider using a battery tender or trickle charger to keep the percent charge topped up without overcharging, preventing sulfation (a condition that damages the battery).
- Avoid Storing on Concrete: Store the battery on a wooden shelf or bench as leaving a battery on concrete leaves it exposed to temperature fluctuations which can deplete the battery over time.
- Inspect Regularly: Over the winter months, check the battery for any signs of corrosion, leaks, or significant loss of charge. Address problems quickly because damage can lead to a battery explosion or fire hazard.
