A Craftsman lawn mower battery typically mounts under the driver’s seat. The battery is primarily responsible for starting the lawn mower engine. Later model mowers require the additional power source for instruments, lighting and other accessories. Little preventative maintenance is needed to keep a Craftsman battery in an operable condition. But when problems do occur, they can be quite frustrating--especially when long grass is waiting in your yard.
Battery overcharging can occur in a couple of different ways. Using an automotive battery to re-charge the Craftsman’s battery after it has been deeply discharged, has a tendency to overcharge the batteries cells. Also, jumping the Craftsman lawn mower battery with a larger car battery may result in an overcharge condition. The result is a damaged battery that will no longer hold much of a charge at all. A visible sign of overcharging is a swollen battery.
With the lawn mower operating under normal conditions, a magneto--much like a car’s alternator--sends current to the battery to maintain a charge. If the magneto malfunctions, the battery will eventually drain from starting the engine or operating the lights. When the mower is running at idle, a voltage of 13 to 14 volts DC are present across the battery terminals is the charging circuit is operating properly.
A Craftsman mower stored for six months or more can easily have its battery drain. Extended storage requires the battery be periodically charged with a low-voltage setting on the charger. Doing so ensures the battery is ready for service in the spring.
Probably the most common battery issue with a Craftsman mower is corrosion build-up on the battery terminals. Visible white or light blue scale on and around the battery posts and terminals indicate a corrosion problem. Removing the battery leads once per season and cleaning them with a wire brush is the best prevention against connection problems. If left undetected, battery terminal corrosion will eventually result in the inability to start the lawn mower's engine, or prevent the battery from accepting a charge.