Recreational vehicles, whether motorized or towed, consist of two primary operational house systems, these being electrical and propane. Both systems must be properly maintained for maximum reliability and safety. Since some newer RVs utilize no propane system at all, it can be said that the most important house system in all RV’s is the electrical system. The central figure in the electrical system is, of course, the batteries.
Just like your brick and mortar home, it is important to keep your home on wheels maintained and healthy. RV owners should understand the importance of proper battery maintenance in the primary areas of winter storage, charging, and regular inspection.
- If the RV is to be stored for more than a few months, the batteries should be removed and stored in a cool, dry location.
- Top off the cells with distilled water, fully charge the batteries and clean the surface and terminals prior to storage. Stored batteries should be recharged every two months.
- Do not place the batteries directly on a concrete floor. Place them on wooden planks to prevent direct contact with concrete.
- Store batteries where they will not be subjected to spark, flame, heat sources, or freezing.
Always be extremely careful and wear gloves and eye protection when working with batteries and electrolyte. Leaving batteries in the RV during storage subjects them to possible fluctuations in humidity, temperature, and parasitic loads, all of which can cause premature battery failure. Battery theft is also a risk in stored RVs. Before removing the batteries, be sure to create a wiring diagram for easier re-installation.
There are four fundamental stages of battery charge for wet cells:
- Bulk – The main part of the charging cycle, which quickly brings batteries to 80- 90% charge using the maximum current of the charger.
- Absorption – Tapers the charge current down and slowly charges the last 10-20% before entering float mode.
- Float – Keeps the batteries “topped up”, maintaining a lower voltage (around 13.7 V) to prevent electrolyte loss caused by overheating the water in the battery.
- Equalize – A high-voltage charge applied periodically to remove any sulfur buildup (sulfation) that accumulates on the battery plates (applies only to wet cell batteries).
Most entry level and many mid-level recreational vehicles utilize inexpensive single-stage chargers that only provide the “float” stage. This ultimately results in sulfation and the batteries never reaching full charge, which reduces the life of the batteries.
An upgrade to a multi-stage “smart” charger is recommended. These units monitor battery condition and apply the stages listed above based on battery charge state. Any single-stage charger can be upgraded, and it is well worth the price to increase battery life. Your RV manual should provide information as to what type of converter/charger you have.
It is important to perform regular inspection and maintenance of RV house batteries. Regularly wipe the battery cases clean, check the electrolyte level, and inspect the terminals and wiring. Also, look for sweating or bulging of the case, which normally indicates a failed battery. Clean the battery posts and tighten the wiring terminals as required. Corrosion may tend to build up on the house batteries, especially in the case of a motorhome. It is a good idea to keep steel wool, fine sandpaper, baking soda, and a toothbrush in your toolbox. Use the steel wool and sandpaper to keep the terminals and posts clean and mix the baking soda with water to create an effective battery post cleaner.
Following these simple steps will help keep your house batteries, the lifeline of your RV, working efficiently for longer.
About the Author:
Coach-Net is pleased to welcome Steve Froese to our team of writers. Steve, an avid RV owner, traveler, and Coach-Net member since 2013, is the principal of “A Word to the Wise Technical Communications”, a published RV author, certified RV technician, and licensed Professional Engineer. He frequently collaborates with the “RV Doctor”, Gary Bunzer, and has worked with the RVIA/RVDA as a technical and training writer and consultant. Professionally, he works as a quality engineer and musician. Watch for more of Steve’s work in upcoming Coach-Net publications.
*Images within the body content were provided by and used with permission from the author.