They look the same, but are they the same? Batteries, especially lead acid batteries, can be pretty perplexing. A motorhome typically has one under the hood and one or more that hooks into the rest of the RV. Why is there a need for separate batteries for each area of your rig? Well, each one serves a different function in your motorhome. This post will explain the difference between a motorhome’s chassis battery and the house battery, and why they’re not interchangeable. As you shop your Grand Rapids, MI, RV dealer looking for a new battery for your rig, use the information in this post to help direct you to the correct one.
The Basics Of Lead Acid Batteries
Invented in the 1900s, the lead acid battery is one of the oldest battery designs. But they work so well that they just keep sticking around through the years. Aptly named, it’s comprised of lead plates and a sulfuric acid solution. The negative and positive plates exchange ions and the acid carries the current created by this exchange through the battery. The chassis battery and the house batteries are made of the same components, but small variations in their designs make a huge difference in how they work.
The Chassis Battery
Inside your chassis battery you’ll find six cells, each of which produces two volts, giving you a 12-volt battery. As the ion transfer happens, the sulfate collects on the plates, and over time the transfer can no longer happen due to this build up. This is called a “dead battery.” When you send a charge into the battery, it removes that sulfate from the plates, putting it back into the water, and then restores the battery’s ability to make that transfer. If the layer of this sulfate gets too thick, or is left for too long, it won’t release even when you charge it. In your chassis battery, the plates are relatively close together and have thin electrodes. This allows it to give that strong punch of power needed to start the motorhome's engine. Because such a strong jolt of power is needed, a lot of the sulfate collects from just one use and needs to be removed quickly to avoid the hardening, which is where your alternator comes in. If you run your chassis battery until it's dead, it can really cause damage and shorten the life of your battery immensely.
The House Battery
The house battery is put together in the same way the chassis battery is but with a few minor differences. The electrodes are thicker which increases the density of the energy created, there’s more space between them, and there’s area at the bottom for the sulfate to fall instead of sticking to the plates. These changes give off a lower current that will power your TV, smoke detectors, and other items that don’t need the punch that the engine requires. It also lasts a lot longer since the build up isn’t as thick and won’t prohibit the movement of energy as much as the chassis battery can. You don’t have to charge them as often, and when they die, it’s not as crucial as when the chassis battery dies. Now, don’t get us wrong, you still need to keep this battery charged as that build up can still stick to the plates, or even become solid in the bottom of the battery and unable to redistribute, but it’s just not going to happen as fast as it does with the chassis battery.
Now that you know the difference between the batteries in your rig, you can see why it's necessary to have the different types and that they're not interchangeable. Let the experienced salespeople at Motorhomes 2 Go in West Michigan answer any of your RV-related questions and help you find the perfect motorhome RV for you! We offer special no-money-down financing on all of our RVs and feature the largest inventory of new and used motorhomes! Visit us in Grand Rapids or go online and take virtual tours of our models.