We have written several articles about deep cycle batteries commonly called house batteries and produced numerous videos over the years so you might be saying, “Ok, we get it already!” However, in the last couple of years, there have been several new battery companies that came into the market, new technology with not only the standard lead-acid and AGM but also Lithium-Ion models as well.
Buying a Good Battery
When I first started in the industry in 1983 at Winnebago we used Goodyear Die Hard batteries and the warranty was through Sears stores across the nation. Back then there were thousands of stores, today I think the last one finally closed somewhere in the Midwest. The battery was good, the issue was for a warranty on the battery you had to take it out of your rig and bring it into a store! A lot has changed since then and there have been dozens of battery manufacturers that have come and gone and the old saying; “You get what you pay for” is still true today.
Batteries simply store energy that is used by the RV and replaced by a refilling or charging system. An acid solution reacts with the lead plates They all have lead plates in cells with acid covering them. The difference comes in the materials used inside the cells. Materials such as thicker positive plates, superior paste, better and fewer welds, and superior plate holders. Less expensive batteries that are offered by discount stores just do not last.
Typically Marine batteries are a hybrid with thinner cells and if they are rated with Cold Cranking Amp (CCA) or Marine Cranking Amps (MCA) they are designed for starting and may not be a true deep cycle design.
Lead Acid Gets A Bad Wrap
Even the good lead acid batteries can go bad prematurely if they are not properly maintained. As the energy is drained and recharged, sulfur coats the plates and needs to be removed during the first stage of recharging. A typical RV converter simply comes on at 13.6 volts until the battery is charged to 12.6 volts and then stays at 13.2 volts at which rate a fully charged battery will not accept a charge. To break up sulphation in a lead-acid battery, the initial charge commonly referred to as “bulk” charge needs to be approximately 14.6 volts. This would require a multi-stage charger such as the Progressive Dynamics “Charge Wizard” technology, a solar panel system with a charge controller, or an aftermarket product such as Battery Minder. Improper charging causes the sulfur level to get thicker and reduces storage capacity. Batteries look like they are fully charged at 12.6 volts but deplete fast due to sulphation.
Another issue with lead-acid is gassing and liquid depletion. As the battery is being recharged it create gassing which is hydrogen and oxygen and the liquid depletes. Therefore it is important to inspect the fluid level periodically and add distilled or deionized water to cover the plates. Low fluid levels expose the plates and cause them to deteriorate prematurely.
Absorbed Glass Mat-AGM
At my seminars, I’ve talked with many RVers that got fed up with their lead-acid batteries and went to AGM batteries because they provide more power and are less maintenance. This is half right, there is less maintenance as they are sealed and do not have gas, and are less prone to sulfation. They do not provide more power initially however, as they are less prone to sulfation, they provide the rated power over the years as the sulfated lead acids will start to underperform as discussed earlier.
All batteries will lose a charge during long periods of inactivity such as storage. Batteries should be recharged when they show under 70% capacity. And they need to be kept from freezing. If you do not have access to 120-volt power to charge or a solar panel, it is recommended to remove the batteries and maintain them store them properly.
Another option is using a solar panel with charge controller or Battery Minder which not only keeps the battery from freezing and properly maintained. This is good for lead acid, gel, and AGM. Not for use with Lithium Ion. Lithium-Ion batteries should be stored at 50 degree temperature and at 40-50% capacity.
In the past, Lithium Ion batteries were very expensive and did not perform well in cold weather. Technology has changed and more companies have developed Lithium Ion batteries that are getting closer to AGM batteries. Granted they are still about twice as much initially, however they can be drained down to almost 0% capacity vs 50% of other batteries so you can get by with fewer overall batteries. Also, they last longer so if you plan to keep your rig for a long time and do a lot of dry camping, the pay for themselves. Plus with proper charging, they are not affected by cold weather as older versions.
About the author: Dave Solberg: Managing Editor, RV Repair Club
For the last 25 years, Dave has conducted RV maintenance and safety seminars, developed dealer and owner training programs, written RV safety and handyman articles, authored an RV handbook reference guide and logged over 100,000 miles on the road in an RV.
RV Repair Club is your go-to online resource for enthusiasts who want quality RV maintenance, repair and upgrade information – a community where passionate RVers can come together to gather knowledge and share their experiences.
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