Deep cycle RV batteries are one of the three commonly-available types of RV batteries, but they’re the ones that are most often misunderstood. With this post, we hope to change that, at least to some degree.

An RVer’s access to power is no minor consideration. We all appreciate traveling with the ability to run a number of appliances and electronic devices. While some RVers accomplish this by being tethered to campground power pedestals, other travelers (like us!) prefer to boondock in the forest, in the desert, on the beach, or even in a parking lot on our way to another great destination! To do that, however, we need battery power.

Starting batteries are easily damaged by being drained too low. So, while they can provide high currents, they can’t handle deep discharges without suffering permanent damage and/or dramatically decreased lifespan.

Deep Cycle Batteries
Deep cycle batteries are designed to provide a long, steady supply of power rather than short power surges. (This is the key difference!)

These batteries are constructed using a smaller number of thicker lead plates, giving them greater resistance to damage from many cycles of being drained (reasonably) and recharged.

rv batteries deep cycle can be drained and recharged many times over. However, it’s best not to deplete a deep cycle battery below a 50% state of charge. For example, if you have a deep cycle battery rated to provide 100 amp-hours of energy, you don’t want to use more than 50% of that energy or 50 amp-hours.

The big difference between deep cycle batteries and other common batteries is the ability of the deep cycle battery to handle multiple cycles of deep discharge. This is important to the process of providing DC power for RV use.

Marine Batteries
Marine batteries can be starting, deep cycle, or dual-purpose batteries.

A dual-purpose battery is kind of a hybrid between a starting battery and a deep cycle battery. It can provide the strong burst of power needed to start an engine as well as provide more long-term power for onboard accessories due to having slightly thicker lead plates.

But, it’s important to know that not all “marine” batteries are necessarily “deep cycle”.

So, unless you confirm that you’re getting a deep-cycle marine battery, you could end up with one that doesn’t meet your needs for providing off-grid power for any length of time. It would also likely become damaged by continuous cycles of deep discharge.

Most RVs come with deep cycle batteries for powering the house portion of the RV. But if you’ve got a motorhome your RV will have two types of batteries.

6V batteries (commonly referred to as “golf cart batteries”) are a type of deep cycle battery that always come in pairs, wired in series (positive terminal to negative terminal), to make one larger 12V deep cycle battery.

This increases their amp hour (ah) capacity, which is the amount of energy they can supply before needing to be recharged.

6V deep cycle batteries usually come in the same form factor as 12V, so within that same size/footprint they can have even thicker lead plates and improved resistance to damage from repeated (deep) charge/discharge cycles.

The thick plates also contribute to the increased amp-hour capacity.