If the battery becomes hot when charging, it is often a sign that your battery charger is overcharging the battery. Charge the battery only for the length of time suggested by the manufacturer and only when the battery is low.
If the RV won't start, this may be the first indication that the battery or the charger has a problem. Most RVs use the same type of lead acid batteries used in your automobile. A lead acid battery with liquid electrolyte (flooded cell) should support normal vehicle operation with little to no maintenance. If your vehicle doesn't easily start, start troubleshooting your battery.
Open the battery caps and look inside, taking care to prevent any debris from falling into the holes. The plastic fill indicator is slitted to make checking this easier. The liquid should reach the plastic extending down from the top, but should not fill all the way to the top. Overfilling causes charging difficulties.
Only use distilled water to refill a battery cell. Other water types contain minerals and chemicals that contaminate the battery cell, causing charging problems. Fill the cell to the bottom of the fill indicator.
After you add water to the battery, run the battery through a charging cycle as recommended by the manufacturer. If the vehicle still has problems starting, have the battery charger checked by a service technician.
Any buildup around or near the battery terminal posts or on the wires connected to them is undesirable. Remove the wires and remove the corrosion with a wire brush or other cleaning system. Reattach the wires and start the vehicle. If the RV appliances still run slow, recharge the battery.
Monitor your battery for further corrosion buildup. If corrosion recurs, check for overfull cells and have the charging system checked by an authorized service technician.
Most RVs have one battery system that starts and runs the vehicle and a second system that provides power to the accessories in the coach. While you might believe that running the motor charges both systems, this may or may not be true. Check the owner's manual or a service technician if both systems are not charging adequately.
Running too high a load on the batteries may discharge the batteries too fast. Run your refrigerator and other high-load appliances on propane or with the rig plugged into a power source to reduce the strain on the battery and charger system.
