RV Battery Maintenance and Charging Guidelines

Trailers and motorhomes have unique power requirements, so choosing the right battery and caring for it properly is an important task.


WARNING: Batteries produce explosive gases. Keep sparks, flames, and cigarettes away from batteries at all times. Protect your eyes at all times. Never lean over battery when jumping or performing other maintenance. Remember, always wear safety glasses when working around batteries!


WARNING: Always wear safety glasses when working around batteries. Batteries can explode! Protect your eyes.

  1. Perform a visual inspection. Inspect for defective or cracked case and cover, and loose or damaged terminal posts or cables. Replace battery and/or cables immediately if any damage is found.
  2. Look for loose connections or hold-downs. Tighten snugly if appropriate. TO AVOID BATTERY DAMAGE, DO NOT OVER-TIGHTEN!
  3. Keep the batteries and battery compartment clean and corrosion free. Dirty, corroded batteries can self-discharge, which will affect performance and life. Clean corrosion with a paste made from baking soda and water. Apply liberally. Any corrosion is neutralized when the solution stops bubbling. Wash off with large quantities of water to avoid environmental damage.
  4. Shine lead posts and terminal ends with a wire brush or steel wool to clean corrosion and assure a low resistance connection. Reassemble and coat lead parts with petroleum jelly or a terminal protection spray. Repaint hold-down, tray and surrounding parts if necessary.


Batteries that are not in use during the off-season must be cared for as follows to extend battery life and reliability:

  1. Disconnect the batteries to avoid self-discharge due to parasitic loads such as clocks, ground faults, etc.
  2. Put batteries into storage fully charged and keep them above 75% state-of-charge. Check state-of-charge every 90 days and recharge if necessary.
  3. Ideally, store batteries in a cool, dry place with temperatures not below 0ºC (32°F) or above 27°C (80°F). Typically, batteries will self-discharge at faster rates at higher temperatures.



    RV Care deep cycle batteries are designed to provide excellent service life in deep cycle applications. The life of an RV Care deep cycle battery will be determined not only by the number of cycles (one discharge + one recharge) it receives, but also by the depth of each cycle. The deeper the discharge, the more damage to the battery plates and consequently the shorter the battery life.

    To obtain maximum service life, your RV Care deep cycle battery should be fully charged every day it is used, even if it is only discharged 25%. Do not completely discharge any deep cycle battery if it can be avoided as the deeper the discharge the less life you will obtain from your battery.

    To fully recharge a battery, you must replace the ampere hours removed from it, plus a 20% charge. This is because a lead acid battery is not 100% efficient on recharging. Do not charge your battery beyond the fully charged state as this also shortens service life.

    The chart below gives you the state of charge at various specific gravities (determined with a hydrometer), corrected to 26.7°C (80°F). Never allow the fluid level in your battery to drop below the tops of the plates because the exposed portion of the plate will become permanently inactive due to sulfation. Check your fluid levels before charging and add distilled water to just above the level of the plates. After the battery is near full charge, recheck the levels and top up to just below the bottom of the filler tube. Overfilling before charging will result in an overflow of electrolyte (due to expansion).


    Always leave filler caps in place, tight and secure to reduce the risk of battery explosion and serious injury! Always wear safety glasses when working around batteries. Batteries can explode! Protect your eyes. Do not charge batteries without proper instruction.

    1. Batteries should be charged if hydrometer reading is below 1.225 specific gravity, or open circuit voltage is below 12.4 volts, or if a load test is below 9.6 volts.
    2. Carefully read and follow the instructions that came with the charger to avoid serious injury, property damage and/or battery damage.
    3. Unplug the charger before connecting or disconnecting a battery to avoid dangerous sparks which can cause a battery to explode.
    4. Do not leave a battery on charge for more than 48 hours to avoid damaging the battery by over-charging. If gassing or spewing of electrolyte occurs, or the battery case feels hot, reduce or temporarily halt charging to avoid damaging the battery.
    5. Stop the charge when two hydrometer or voltage readings recorded two hours apart indicate no increase. Further charging would be useless and may damage the battery and shorten its life. If the battery won’t come up to full charge, replace it.
    6. NEVER attempt to charge a frozen battery. To avoid explosion and serious injury, allow it to warm to 16°C (60°F) before charging.
    7. NEVER leave a battery on a trickle charger longer than 48 hours. Serious damage to the battery WILL occur.



    While our VRLA batteries accept a charge extremely well due to their low internal resistance, any battery will be damaged by continual under- or overcharging. Capacity is reduced and life is shortened.

    Overcharging is especially harmful to any VRLA battery because of the sealed design. Overcharging dries out the electrolyte by driving the oxygen and hydrogen out of the battery through the pressure relief valves. Performance and life are reduced.

    If a battery is continually undercharged, a power-robbing layer of sulfate will build up on the positive plate, which acts as a barrier to recharging. Premature plate shedding can also occur. Performance is reduced and life is shortened.

    Therefore, it is critical that a charger be used that limits voltage. The charger must be temperature-compensated to prevent under or overcharging due to ambient temperature changes.

    IMPORTANT CHARGING INSTRUCTIONS: The warranty is void if improperly charged. Use a good constant potential, temperature-compensated, voltage-regulated charger. Constant current chargers should never be used on VRLA batteries.


    VRLA batteries can be substituted in virtually any flooded lead-acid battery application (in conjunction with well-regulated charging), as well as applications where traditional flooded battery can’t be used. Gel batteries excel in super-deep discharge applications. AGM batteries excel in high current, high power applications and in extremely cold environments.

    Because of their unique features, GEL & AGM batteries are particularly well suited for:


    Download the pdf version of our Maintenance and Charging Guidelines