Neglected RV Batteries
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 can deplete 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 the electrolyte level needs to be checked.
Checking the electrolyte level on a regular basis can save your flooded lead acid batteries. Check the water level monthly and if you leave your RV plugged in with the batteries being charged by the converter battery charger check it bi-monthly. If your converter doesn’t have a three stage charger the battery is getting a constant charge of 13.5 volts. When the batteries are topped off this voltage is too high for a float charge and it can boil off the electrolyte over time. 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 you do come in contact with battery acid flush the exposed area immediately with a lot of cold water.
When you add water only use mineral free water. Distilled water is best, and only fill the cell to 1/8 inch below the fill well. Overfilling cells will cause battery acid to overflow. When this happens the battery will lose some of its capacity and corrosion will build up on and around the battery. Water should only be added after fully charging the battery unless the water level is already below the plates.
Follow these steps for watering the battery. Remove the vent caps and look inside the fill wells. Check the electrolyte levels. The minimum level required for charging the battery is at the top of the plates. If it’s below the plates add enough distilled water to cover the plates before you charge the battery. Fully charge the battery before adding more water. When the battery is charged remove the vent caps and check the electrolyte levels. Add distilled water until electrolyte level is 1/8 inch below the fill well. Replace and tighten all vent caps.
Mark J Polk
RV Education 101