The RV coach battery(s) are one of the most important and neglected components in the RV. The converter in an RV also has a battery charger. Whenever you are plugged in to electricity, or the generator is running, the coach battery(s) is being charged. It is also being charged by the automotive alternator when you are driving the RV or in the case of a towable RV if you had a charge line wired into the light plug. This constant charging depletes the electrolyte level in the battery(s) cells. If the battery is not maintained properly it will fail much sooner than it should. Depending on how often the battery(s) is being charged will determine how often it needs to be checked.
You should check the battery(s) at least monthly and if you use the RV on a regular basis and / or you leave it plugged in when you’re not using it you may need to check the battery(s) more often. If you are not familiar with batteries and battery maintenance have them checked by an authorized service center. Batteries can be extremely dangerous. They emit gases that are explosive and they contain a very corrosive acid. If you do perform your own maintenance certain precautions must be taken.
Do not use an open flame or smoke around batteries. Avoid any electrical arcing or sparks around the battery(s). Wear protective clothing and safety glasses and avoid getting any battery acid on your skin or clothes. If the electrolyte levels are low in the cells use only distilled water to fill them to the proper level. If you do come in contact with battery acid flush the exposed area immediately with a lot of cold water.
Check out my Deep Cycle Battery Care and Maintenance for RV's and Boats DVD