My Cub Cadet 129 Hydro Will Not Charge the Battery

Battery Life

• Because the Cub Cadet 129 was manufactured so long ago, the chances are that the battery o it is not the original one. If the replacement battery is out of warranty, it may contain dead battery cells that won’t accept a charge. If your battery is within warranty or the normal expected lifespan, have it tested at an automotive store for charge capacity. If it isn’t reaching the 12-volt charge capacity in an acceptable time frame, you may need to replace the battery.

Connections

• Every battery has positive and negative poles. The positive terminal, which has a red wire, is the power supply line to and from the engine. The negative terminal, indicated by a black wire, provides the ground so that traveling voltage doesn’t leave your Cub Cadet’s engine. Both wires have terminals that may become corroded over time, leaving a dusty coating on the poles. If such a substance is on your Cub Cadet’s battery, clean it off with a stiff wire brush and baking soda.

Voltage Regulator

• The electrical system on engines can generate a lot of voltage to operate various controls, such as the PTO blade and dashboard. The Kohler K 301 A engine has a voltage regulator that determines how much voltage will be expended to charge the battery. If the engine has been replaced with a newer one, the regulator-rectifier performs the same function. If this part gets out of proper resistance or fails, voltage to your battery may be limited, reducing its charge capacity.

Low RPMs

• The Cub Cadet 129 is designed to operate best at full speed. Excessive idling does not generate enough electricity to keep the battery charged. If your mower has trouble reaching high RPMs, check the fuel system for clogs or malfunctioning parts, such as the fuel pump or carburetor. Otherwise, do not let your engine idle for too long. If you don’t plan to operate your 129 for a period of time, disconnect the battery to prevent it from discharging during storage.