My LX186 John Deere Lawn Mower Battery Will Not Stay Charged

Battery Cells

• The John Deere troubleshooting guide for lawn tractors suggests that a dead battery cell can keep the battery from charging. Dead battery cells can occur if engines stay in extreme weather conditions -- hot or cold -- for lengthy periods of time without charging. The cells discharge outside of the case and start to coat it. This will prevent the cell from taking a charge.

  If you suspect your battery has a dead cell, test it to see its current charge capacity. Run your engine at idle for 30 minutes, and then test it again. If the charge load is significantly below 12 volts, the battery may need to be replaced.

Unused Battery

• An unused battery can also lose its charge capacity. If a battery is not used for three to four weeks and is still connected to the LX 186, your battery can die. For off-season storage, disconnect the battery from its Kawasaki engine and put it in a clean, dry place to reduce the possibility of corrosion. Before using it again, put the battery on a charger for six to eight hours.

Terminals

• The battery in your LX 186 has two terminals that transmit the voltage into and out of the cells. Over time, these terminals and their posts can become corroded and interfere with transmission. The terminals and posts should be checked and cleaned regularly. Clean them by using baking soda and a stiff wire brush. Ensure that terminals are completely torqued onto the posts to prevent any arcing or gaps that can reduce the charge.

Engine Speed

• Running the 17-HP Kawasaki consistently at low speeds reduces the charge capacity. Running at low RPMs reduces the charging output lower than the battery is using it, while running at idle puts almost no charge output. It’s best to operate the LX 186 at full throttle to maximize charge capability. If possible, turn off the tractor instead of sitting at idle for lengthy periods of time.