Deep Cycle Battery

Deep cycle batteries for RV power

Batteries aboard our RV

The deep cycle batteries used on MsTioga are manufactured by Crown Battery Manufacturing Company and are their Model CR-225. We use six of these deep cycle batteries.

The batteries are connected in series pairs and and the three pairs are connected in parallel. These batteries are rated to deliver a Reserve Capacity [RC] of 115 minutes @ 75 amps.

Battery cost is $108/each installed in my RV.

Our Crown Deep Cycle battery bank purchased from American Battery Company located in Escondido, California.

Battery Maintenance
The deep cycle battery bank needs service once each month.
  • After re-charging, electrolyte water level checked. Distilled water added to raise the electrolyte level to the bottom of the filler vent. Avoid overfilling! The electrolyte may overflow.
  • The batteries are wiped clean.
  • Cable connections to each battery lug are checked for tightness. We are very careful not to tighten the battery lug nuts too much. The studs may pull out from the battery.
  • Specific Gravity for Crown Batteries is 1.280 for a 100% state of charge. If batteries are less than 1.280 Specific Gravity, the equalization time written about below is upped to 3-hours.

    Daily 30 minute equalizing charge.
    Current thinking for wet (flooded) batteries is that short daily equalization has a better long term effect on prolonging battery service life than less frequent, longer duration equalization cycles. Our battery bank is equalized once each day. First the bank is brought to 100% charged condition, then a 30 minute equalizing charge is given to the bank.

    A battery desulfator is used on this battery bank to reduce the buildup of sulfate crystals on the plates of the batteries. Sulfation occurs when batteries discharge. We try to make sure that our battery bank is 100% recharged everyday, and after every use. This recharging reduces the chance of early battery failure.

    It is a mystery if a desulfator actually works or not. There is no way to check. I am using a desulfator just in case these devices really do work.

    Annual maintenance cleaning.
    Each 6 volt deep cycle battery sits in its own plastic battery tray. These battery trays are very important. Batteries seem to exude electrolyte, no matter how clean they are maintained. At least once each year, we take apart the entire battery bank, clean each battery all over, along with the battery trays and the entire battery compartment. Each copper cable end is cleaned until the copper is shiny bright. Battery studs are cleaned. All nuts, washers, lock washers are cleaned or replaced as necessary.

    Battery Mat
    In April, 2009, The Battery Mat was installed in each battery tray. The Battery Mat absorbs and neutralizes battery acid. You may learn about our Battery Mat installation in our blog post [link].

    Making your own battery cables.
    We made up our own battery cables, in order to have each length of cable be the exact length required. The cable used to connect our deep cycle batteries was purchased from a welding supply dealer. It is necessary to use very large cables to connect batteries. We use 2/0 size cable. Matching cable lugs are attached to this cable which is also purchased from a welding supply dealer. Talk to your welding supply dealer about buying a crimper if you are going to fabricate your own battery cables. Buy the special "copper cutting" cable tool in order to cut the cable properly, and square. Spending the money to buy these special tools to make your cables is important. Spend the money to do it right, OK?

    Hydrocaps are a replacement for the vent caps that come with the batteries. Hydrocaps convert the hydrogen gases that are given off during the charging process into water, and return that water to the electrolyte of the battery. Hydrocaps should be replaced with original caps during the equalizing charge. Do a search for "hydrocaps" to find suppliers.

    Water Miser Battery Caps
    Water Misers are molded plastic "flip-top" vent caps designed to reduce and ease maintenance on flooded Lead-Acid batteries. There is no need to remove the caps when charging, filling, or equalizing the batteries. When charging, the plastic pellets capture up to 90% of the moisture and acid droplets. Do a search for "water miser battery caps" for more info.

    Water Miser yellow caps
    on our battery bank.

    Absorbed Glass Mat (AGM) batteries.
    AGM batteries are sealed, and require no additional water. AGM batteries are spill proof and may be used in a semi-enclosed area such as an RV's storage compartment. AGM batteries cost much more than golf cart batteries. If your deep cycle batteries are going to be stored in a semi-enclosed space, AGM batteries should be used.