Will a Bad Battery in a Lawn Mower Cause it to Not Run?

Corroded Terminals

• The battery used in lawnmowers operates with a positive and a negative terminal. These opposing terminals allow the current to flow from the battery to the electrical systems on the mower. However, these terminals directly connect the battery to the engine and tend to sustain the most damage. Old or bad batteries may start leaking a small amount of the corrosive acid. When this acid builds up on the terminals, it will eventually short out the electrical connection.

Loose Connections

• Similarly the metal bands that wrap around the terminal can also get corroded, bent or damaged. If the connection with wires and the battery doesn’t stay firm, the electrical current will stop flowing, and the mower won’t run. Whenever lifting off these wires and the bands, take them off slowly, wiggling them back and forth if necessary. Don’t bend the metal bands or use any tools to get them off as this may damage the connectors.

Bad Battery

• Every battery has a set amount of acid that will generate a certain number of hours of electrical conductivity. However, once this acid is depleted, it can’t be refilled and the battery will need to be replaced. In some circumstances, a crack, leak or other problems associated with a bad battery can cause this acid to leak, prematurely ending the battey's life. When inspecting the battery, look for corrosion around the terminals, on top of the battery or near the metal parts of the engine block.

Replacing the Battery

• Any bad battery or leaking battery will need to be replaced before the mower can operate again. Since batteries can last several years, this maintenance won’t need to be done frequently. When replacing the battery, it is crucial to replace it with the right type, as other batteries may damage the engine or electrical systems. Always take care when lifting off the connecting bands and install them firmly after setting the new battery in. Dispose of old batteries according to local environmental regulations.