RV Battery Maintenance

Ultrapower RV deep cycle batteries

There are two types of RV batteries: deep-cycle AGM or gel batteries and deep-cycle flooded or wet batteries.  The following are tips specifically for maintaining the deep-cycle flooded or wet batteries and have been taken from the Trojan Battery Company’s “User Guide”.    All deep-cycle flooded or wet batteries are maintained in the same manner.  Begin by periodically examining the outside appearance of each battery.  The tops of the batteries and terminal connections should be clean, free of dirt and corrosion, and dry.

Corrosion can build up on terminals if they are not kept clean and dry.  To prevent corrosion, apply a thin coat of terminal protector spray.  Terminal corrosion may adversely affect the performance of the battery, and it could present a safety hazard.  Check that all vent caps are secured properly on the battery.  Then clean the top of the battery, terminals and connections with a cloth or brush and a solution of baking soda and water  (1 c baking soda to 1 ga water).

If fluids are on the top battery this may mean that the battery is being over-watered or overcharged.   Deep-cycle flooded/wet batteries need to be watered periodically.  The frequency depends on battery usage and operating temperatures.  Check new batteries every few weeks to determine the watering frequency for your application.  It is normal for batteries to need more watering as they get older.

To water a deep-cycle flooded/wet battery first fully charge the battery prior to adding water.  Deep-cycle flooded/wet batteries release small amounts of gas during usage, especially during the charging process and need to be charged in a well ventilated area.  Only add water to discharged or partially discharged batteries if the plates are exposed.  In this case, add just enough water to cover the plates and then charge the batteries and continue with the watering procedure by removing the vent caps and place them so that dirt does not get on the underside of the cap.  Check the electrolyte level.  If the electrolyte level is well above the plates then it is not necessary to add more water.  If the electrolyte level is barely covering the plates, add distilled or de-ionized water to a level 1/8″ below the vent well (this is the plastic shield inside the vent hole).  After adding water, secure vent caps back on batteries.

Check battery cables and connections.  Use an insulated wrench to replace any damaged cables and to tighten any loose connections being careful not to over tighten the connection which can result in terminal breakage and loose connections, thus resulting in meltdown or fire.

Deep-cycle flooded/wet batteries must be placed upright at all times.  Fluid in the battery will spill if the battery is placed on its side or at an angle.

Charge batteries before placing in storage and place them in a cool, dry place protected from the elements.  Disconnect from equipment to eliminate potential power draws that may discharge the battery.  Batteries gradually self-discharge during storage.  Monitor the specific gravity or voltage every 4 to 6 weeks.  Stored batteries should be given a boost charge from a battery charger and maintainer,  like the MotoBatt Little Boy,  when they are at 70% state of charge or less.  Avoid freezing temperatures, if possible, during battery storage.  Batteries can freeze in  cold temperatures if they are not fully charged.  If batteries are store during cold, winter months, it is critical that they are kept fully charged and disconnected from any systems that would have a power draw.  When batteries are taken out of storage, recharge before use.

MotoBatt LIttle Boy battery charger and maintainer