Ask Dave: What RV batteries do you recommend for both chassis and house?

Dear Dave,
What RV batteries do you recommend for the chassis and house? My rig has sat in dry storage for two years and after a jump it doesn’t seem to be recharging. Do “any” Group 24 batteries work for the chassis and “any” Group 31 work for the house? There are two of each. —Kevin, 1999 Fleetwood Discovery

Dear Kevin,
You will want to get automotive batteries that are rated in Cold Cranking Amps (CCA) for the engine or chassis batteries. Since your Fleetwood Discovery is a diesel pusher, the higher the better. Winnebago uses NAPA batteries and typically 950-1000 CCA. According to their chassis “guru,” they researched the quality of materials used and service availability. Your chassis most likely is a Freightliner and came with Freightliner labeled 1000 CCA batteries. However, they are not made by Freightliner but rather a third party, most of which are not available. Freightliner states that the Exide 1000 CCA are equivalent.

I do see several owners putting Interstate in as they are affordable and are at service centers all over the country. We have used a 1996 Monaco Dynasty for video content at The RV Repair Club and the owner put in a set of Interstate batteries. Six years later they are still cranking the engine over just fine.

The house batteries need to be deep cycle batteries that are designed to be drained and recharged, known as a cycle. They are rated in amp hours (aH), which is how long they will provide power.

The number of volts and batteries matter

Your Fleetwood originally came with four 6-volt batteries connected in series, which is positive to negative on two, which gives you a 12-volt bank. The two “banks” are connected parallel, which is positive to positive and negative to negative, which doubles your amp hours. If you only have two batteries, as indicated, I would assume the originals went dead within 2-3 years and they were either replaced with only two 6-volt batteries or two 12-volt ones.

Lead acid batteries can only be drained approximately 50 percent and are rated in Groups such as Group 24, 27, and 31. Some owners choose the 6-volt batteries as they typically have more cycle capacity and therefore a longer lifespan. You do need two batteries to create a 12-volt bank, so if you want to expand the amp hours you will need to add two more each time.

Amp hours needed

The amount of amp hours you need depends on how often you camp without being connected to an electrical source, which means you will need to depend on the house battery capacity to run 12-volt components such as lights, roof vents, water pump, and any appliance that runs on LP. Then you need to factor in how long you plan to dry camp and the number of people that will be using the components. It’s not an exact science since it is hard to calculate how much time you will be using components and other factors like temperature and weather conditions. Go Power! has a good worksheet that at least helps identify the components and gets you thinking about the variables.

You can download a pdf copy here.

Factors to consider when asking, “What RV batteries are best?”

Once you determine the approximate amp hours you need, you have several choices of RV batteries. The best battery for your rig depends on how much dry camping you plan to do and what appliances you need to run. Lead acid batteries are the most inexpensive but do need more maintenance. The plates are “flooded” with acid and as the power is drained, sulfur coats the plates and needs a multi-staged charger to break up the sulfation.

The average converter/charger does a 13.6-volt charge until the batteries reach 12.6 volts and then drops to a 13.2-volt maintenance charge. This does not break up the sulfation and they lose storage capacity. Because of this, many RVers choose to go a different route. You need a multi-stage charger that does a high-voltage bulk charge (+/- 16-volts) and then goes into a float and equalizing charge. Some larger inverter/chargers will do this, as well as larger solar charging systems with a charge controller.

AGM batteries

Absorbed Glass Mat (AGM) batteries are sealed and typically are less prone to sulfation but are more expensive. Lithium batteries are the ultimate in amp hours as they can be drained to almost 100%. However, they are much more expensive. If you are doing a lot of dry camping and considering lithium, it would be wise to read this article about the compatibility of lithium and your rig.

To simplify all this: You want a good automotive battery with 1000 CCA for the engine batteries and then need to determine how much dry camping you will be doing to figure out the amp hours required. Then you can decide what type of battery best fits your camping needs and your budget.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here. 

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