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RV Battery Monitor: Vital Tool For Battery Health & Longevity

RV Battery Monitor: Vital Tool For Battery Health & Longevity

RV batteries are a critical feature of the RV lifestyle, especially for those of us who need to be connected to technology on an ongoing basis. But RV batteries can also provide the power for lights, refrigeration, heat, water pumps, and other comforts that we’ve all grown accustomed to being integral to RV life. One component of an RV battery system that sometimes gets overlooked, but is critically important, is the RV battery monitor.

Today we’re taking a closer look at this important piece of electrical equipment. We’ll look at the most important features of an RV battery monitor, and what makes the monitor such a key part of the system.

What Is an RV Battery Monitor?

Most RVers and campers desire some level of power while camping. When you’re parked at a campsite where you’re connected to shore power, your access to power can be virtually unlimited, depending on the size and type of RV and the amperage available at the campsite. But when you’re boondocking as we love to do, you need to have a way to store power for later use, which is where RV batteries come into play.

Your battery bank will likely be charged as you drive, and of course when you’re connected to shore power. You may have also have a solar array, as we do, with which you can harness the awesome power of the sun to charge your batteries. Then you’ll use the power you’ve stored in that battery bank whenever you’re camping off the grid.

Any way you slice it, most RVers store power in a battery bank of some sort. This “bank” could be anything from a single battery to a bank of several batteries, to a large-capacity lithium house battery like we have from Xantrex.

Using our Xantrex lithium battery requires a RV battery monitor.

Our Xantrex Freedom eGEN Lithium Battery stores the sun’s power generated through the large solar array on the roof of our RV.

But, how do you gauge how much power you’ve consumed from your house battery bank and how much is left? How do you keep an eye on the condition of your battery bank so that you don’t drain them so low that your batteries are at risk of suffering damage?

That’s where the RV battery monitor comes in. Unfortunately, many RVs aren’t equipped with a good RV battery monitor, so may need to consider installing one yourself or having one installed.

Let’s take a look at why an RV battery monitor is so important.

Why Does My RV Need a Battery Monitor?

You’ve got a fuel gauge on your RV, and it gives you critical information about how much fuel is left in your fuel tank, and how far you can drive before you run out of gas, stranding yourself. As the gauge shows the fuel level getting low, that’s your signal to pull into a gas station to refuel.

An RV battery monitor gives you similar information about the condition of your battery bank. It tells you how much power is left before you’ll run out. More importantly, perhaps, it tells you when your batteries are approaching a level so low that it could damage them (lead-acid batteries in particular), shortening their lifespan.

So, you need to know the state of charge of your batteries at all times – not only because you don’t want to run out of power, but also because monitoring current and charge levels helps you to maintain and preserve the life of your batteries.

An RV battery monitor helps to preserve the health of your battery bank.

Knowing the state of charge of your batteries at all times not only prevents you from running out of power but also helps to preserve the health of your batteries.

What Features Should I Look For In An RV Battery Monitor?

There are a number of features that are important to a high-quality RV battery monitor. Let’s take a look at those features one by one, after which we’ll mention a few monitors that provide all of the features we’re highlighting here.

Does the Monitor Provide All the Information You Need?

One of the most important features of a good RV battery monitor is that it provides critical battery system information. This would include such metrics as the amount of energy going into your batteries to charge them and the amount of energy being consumed at any given point in time. This information should be provided in Watts (power) and in Amps (current).

You’ll also want the monitor to tell you the percentage of total battery capacity remaining, in real-time, as well as how much time remains before your battery will be depleted (and, conversely, how much time remains before your battery is fully charged).

Many RV “battery monitors” that come installed by the manufacturer are specifically inaccurate in this arena, displaying simple LED lights showing battery charge in 25% or 33% increments (E, ¼, ½, ¾, F or E, ⅓, ⅔, F for example).

Is the Display Easy to Read and Use?

As with any type of monitor, you want an RV battery monitor to be easy to read and easy to understand. Some LED displays are notoriously difficult to read. A good display will allow you to glance at your battery monitor and see exactly what’s happening with your battery bank. This means the screen is easy to read in daylight or at night, and the information is presented in an easily understandable way.

A good RV battery monitor display is easy to read.

A good display is easy to read in daylight or at night and offers critical information at a glance.

Does the Battery Monitor Come with a Shunt?

A shunt is a very important component of an RV battery monitor. A shunt, when connected to a negative battery cable, measures the energy flowing into and out of a battery and the information is sent back to the monitor where you’ll see the information on the screen in real-time.

All power going into and out of the battery bank needs to go through the shunt in order to provide accurate information about the state of your battery bank.

Essentially, what happens here is that measurements from the shunt are used by the monitor to determine how much power you’re consuming (power being removed from the battery bank) and how much the battery is charging (power going into the battery bank). This information allows the battery bank’s state of charge to be calculated, ultimately showing you the percentage of power remaining for your consumption.

Does the Monitor Offer Alerts and Event Triggers?

The reason we want the information provided by an RV battery monitor is so that we can take appropriate action when necessary. For this reason, it’s also good to have a battery monitor that sends alerts to notify you of certain critical battery status changes.

If you have a battery monitor that sends alerts to your phone, for example, you can be alerted to issues related to critical battery capacity levels approaching as well as voltage level, current draw, and even temperature values.

Event triggers are also a very important feature of a battery monitor because they can allow you to program your monitor to trigger a particular action if a certain event should occur. For example, you could program your RV battery monitor to turn on your generator if your battery level should hit 50%. You could also program it to turn the generator off once the batteries are charged sufficiently to a level you program into the battery monitor.

Clearly, alerts and triggers are important features of a good RV battery monitor, especially because you’re not always inside your rig to monitor the status of your RV battery bank.

A good RV battery monitor will trigger your generator to start if your battery bank falls to a critical level.

A good RV battery monitor will offer the ability to program alerts and triggers for certain events. For example, your battery monitor can trigger your generator to start up if your battery bank reaches a pre-programmed level.

Is the Firmware of the Monitor Upgradable for Longevity?

An RV battery monitor comes with software embedded into the system that essentially sends instructions to the system. Software that is embedded into hardware like this is called firmware.

From time to time, the manufacturer may need to update the firmware of your battery monitor system in accordance with changes in technology. When you’re shopping for a battery monitor, you’ll want to make sure the firmware is upgradable (via WiFi or Bluetooth) so that you can take advantage of technology upgrades without having to buy a new battery monitor.

What Are Some Popular RV Battery Monitors With These Features?

Following are five battery monitoring systems that check off all the criteria we’ve noted above. The ability for these systems to provide all of these features reliably is surely the reason they’re five of the most popular RV battery monitors on the market.

All five of these battery monitors will provide everything you need to gauge the status & health of your battery bank/electrical system and much more.

For even more detail on each of these options, check out or other article: 5 Best RV Battery Monitors

An RV Battery Monitor is an Important Component of an RV Electrical System

Regardless of the type of battery monitor you may be interested in using, a high-quality RV battery monitor is a very important part of your RV’s electrical system. Without it, you have no accurate gauge of the condition of your battery bank.

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Friday 8th of September 2023

Amazon doesn't give very good info on the features, i.e. the current used, current being charged with, etc. I'd like to see the "future post" give details on these monitors. Sorry being new to the solar setup. I need to be spoon fed.


Saturday 8th of October 2022

Try products from Battery Failsafe Devices, Low Battery Monitor Alarms. The products are great to monitor battery voltage. Can be used for +12 to +72 volts

Scott Floyd

Sunday 19th of December 2021

This is a very good article. I am looking to upgrade to AGM or LiFePO4 and the stock percentage light monitir in my 2001 Monaco Diplomat won't cut it as part of the configuration. Thanks and I will watch for future posts.

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