This article discusses both Lithium-Ion and deep cycle Lead Acid battery break-in and maintenance tips for electric riding mowers. This information can also be used for all the Lithium-Ion and Lead Acid batteries you have around your home. (If the information in your operator’s manual is different than what I show here – follow the operator’s manual during the warranty period)
Lithium-Ion Battery
Lithium-Ion battery packs for residential mowers are currently custom-built for the mower manufacturer. They range from 48-100 volts and 1000-6000 Watt-Hours. The packs are generally replaced as a complete unit.
Lithium-Ion Battery Break-in Tips:
- Upon delivery of your mower, charge the battery to 100%.
- Run the mower from full charge to 2-3% battery charge, and recharge to 100%.
- Repeat this 4 times, recharging fully to 100% each time.
- Once completed the battery will now perform at its peak level.
Lithium-Ion Battery Maintenance Tips
To get the longest life the battery should regularly be discharged to no less than 20%, don’t use quick/superchargers, charge only when necessary, store the battery at 60%, and don’t charge to 100% when storing the battery for more than a week. Reference: Are you killing your lithium batteries?
- Store Lithium-Ion batteries above freezing and below 104 degrees F.
- To get max life store batteries long-term with 60-80% charge.
- Li-ion batteries like the ones currently used in residential mowers can handle only 1000 to 1,500 charges. Don’t recharge a battery if you’ve used it for just a few minutes. (Any time you charge the battery it counts as a charge whether the battery is at 20% or 95%)
- Don’t leave them in the car—either in the passenger area or the trunk. Heat (above 140 degrees F) and subzero cold can reduce battery life by 15 percent.
- Storing a battery in direct sunlight can really heat it up, so shield it from the sun.
- Don’t store a discharged battery that has less than one-quarter charge. Give it a full charge and then store it.
In the commercial lawn & garden industry companies like Gravely, Mean Green and Briggs & Stratton are quickly developing battery and charging systems that will give you the longest battery life but we don’t have the latest tech in the residential lawn & garden industry yet. You will eventually see Lithium-Ion batteries that automatically discharge to the proper storage percentage and chargers that tell you the condition of the battery and how many charges the battery has had. Companies like DJI (drones), Milwaukee (Tools), Spektrum (radio control) and Tesla are leading the way and hopefully, the tech will get to residential L&G soon.
Lead Acid Battery
Lead-acid batteries for residential mowers are currently off the shelf 12 Volt 75-100AH AGM or FLA batteries externally wired to give 36, 48 or 60 volts to the equipment. The batteries are generally replaced as a set.
Lead Acid Deep Cycle AGM/FLA Battery Break-in Tips:
- Upon delivery of your mower, charge the battery to 100%.
- Run the mower from full charge to 50% battery charge, and recharge to 100%. Leave on the charger for 24 hours.
- Repeat this 4 times, recharging fully to 100% each time. Leave on the charger for at least 24 hours each time.
- Once completed the battery will now perform at its peak level.
Lead Acid Deep Cycle AGM/FLA Battery Maintenance Tips:
Battery life fluctuates a lot based on temperature, depth of discharge and maintenance.
- To get the longest life the battery should regularly be discharged at no more than 50%. (A typical deep cycle battery has a life span of 250-500 cycles but if you regularly discharge it below 50% that life span will be reduced to 100-200 cycles. Your battery life span can be even less if you regularly run your battery to 20% or less)
- Store Lead Acid Deep Cycle AGM/FLA Batteries above freezing and less than 80 degrees F.
- Lead Acid batteries can be stored in any charge condition above 20%. To get the longest life the batteries during long term storage the batteries should be checked and float charged monthly.
- The ideal storage temperature is 50°F (10°C). In general terms the higher the temperature, the more chemical activity there is and the faster a sealed lead acid battery will discharge when in storage. Tests, for example, a typical SLA battery would need recharging within two months when stored at 104°F (40°C) compared to 18 months when stored at 41°F
- When it comes to the cold electrolyte in a fully charged battery can withstand temperatures down to -33°F (-36°C) before freezing. When fully discharged the electrolyte is basically water so it will freeze at 32°F (0°C).
- Sealed lead-acid batteries need to be kept above 70% State of Charge (SoC). If you are storing your batteries at the ideal temperature and humidity levels then a general rule of thumb would be to recharge the batteries every six months.
Jean-Pierre White
The advice regrading lithium ion battery cycles seems off. Lithium Ion Batteries are rated for full cycles. Fractional charges do not count the same as a full cycle. That’s how electric cars work and mowers will not be any different. Topping off above 80% is bad for the battery, but charging from 30% to 80% will only count as half a cycle.
I do agree with 60-80% charge level, 100% charge will reduce life of the battery.
ElectricLandscaper
Hey Paul, great article on lithium-ion and lead acid batteries used in electric riding mowers. I love the maintenance tips. Some people tend to underestimate the importance of the maintenance of their batteries. The better you keep up on the maintenance and care, the longer the batteries will last. (Obviously haha). For people who didn’t know, if you are trying to dispose of an old electric lawn mower battery, you can take them to home Depot, Lowe’s, etc and they will safely dispose of these batteries free of charge.