Although the deep cycle house batteries in your RV are designed to withstand up to 80 percent depth of discharge, that’s only on paper. If you want your house battery to last longer and thus save money, try not to deplete your battery by over 50 percent.
To ensure this, you will need the best RV battery monitor to measure how much charge your battery has left at any given time, as well as other indications of battery performance and health.
To help you pick 12V battery monitors that suit your needs and budget without all the headache, here’s an in-depth review of the 10 RV battery monitoring systems for ensuring optimal battery life. Learn how to use them, as well as crucial buying criteria and answers to common questions.
- Best Overall Shunt Monitor: Victron BMV-712 Battery Monitor
- Best High Range Shunt Monitor: Renogy 500A Battery Monitor
- Best All-In-One Shunt Monitor: bayite DC 6.5-100V 0-100A Digital Power Meter
- Affordable All-In-One Shunt: MNJ MOTOR DC Battery Monitor
- Best Voltmeter for Dual Battery RVs: MICTUNING LED Digital Double Voltmeter
- Best App-Control Voltmeter: ANCEL BM300 Bluetooth Battery Tester
- Most Affordable Voltmeter: ProShopping DC Battery Meter
Why You Need The Best RV Battery Monitor
Perhaps one of the first things RV owners need to learn with regards to maintaining their home on wheels is the workings of their 12 volt house battery, and every related device and accessories designed to maximize battery’s lifespan and performance. A recap of Battery 101 lessons: you should try your best not to deplete your 12 volt battery bank down to less than 50 percent depth of discharge. Doing so once or twice would not kill the battery off, but the more this happens, the shorter the battery’s lifespan.
This is utterly important, since a dead or malfunctioning house battery can leave you stranded in the middle of nowhere. It will also cost you hundreds of dollars to replace the battery bank, not to mention the money and time spent to rescue yourself from being stranded.
For this reason, every camper must check the state of discharge of their house battery regularly to make sure the battery is never too depleted. But it’s not very practical and convenient having to manually use a voltmeter to test the amount of voltage a battery has in store every now and then.
This is where a battery monitor for RV comes in. When installed, the monitor will constantly measure the state of discharge of your battery and display it on the screen as a percentage. You only need to mount the monitor in a high traffic area and glance at it every now and then to keep an eye on your battery bank.
Types of RV Battery Monitor and How They Work
There are two types of RV battery monitor systems: voltage-based systems and shunt-based systems. In summary, battery monitors that rely on shunts are more accurate. They cost a bit more than the simple voltage-based type, but it’s totally worth it.
Voltage Based Battery Monitors
Voltage-based battery monitors, which are often called voltmeters, measure battery voltage in real time but can only estimate the state of charge based on voltage. This is not very accurate as voltage can fluctuate with changes in temperatures and humidity. This type of battery monitor can even produce slightly different results with two similar house battery banks.
While voltmeters are cheaper and simpler than the shunt based type, its voltage readings don’t tell you anything about the battery’s performance or your power consumption, other than the amount of voltage stored in the battery at a given time.
Voltmeters don’t tell you how much power is consumed by your RV system, or whether your battery is charging or not and how fast when you are using a solar system or the alternator to top off your battery. This information is all crucial in identifying overly power hungry or malfunctioning electrical devices or systems in your RV and shutting them off in critical times, or spotting any fault with the house battery itself before it’s too late. Not knowing this information can leave you in the middle of nowhere with a prematurely dead battery.
Shunt Based Battery Monitors
Meanwhile, shunt-based systems use a special device called a shunt, which is installed between the battery’s negative terminal and all the electrical systems or devices that connect to it and consume power from the battery. The shunt can measure battery voltage but more importantly, it measures in real time the amount of current coming in and out of the battery.
It then uses this information to calculate the amount of charge left in the battery, which allows for battery accuracy then calculations based on battery voltage.
The shunt also uses collected data to calculate the power unit’s average and running energy consumption and projected remaining battery runtime. More advanced monitors of the type can also rely on the data it receives to offer critical information on the battery’s performance and health.
Related Reviews: Best RV Lithium Batteries
10 Best RV Battery Monitor Systems: In-Depth Review
Without further ado, let’s dive right into this delicious list of RV battery monitor reviews. Here are 10 reasonably priced battery monitoring systems that are accurate, easy to install, easy to read and use, and will last you a long time down the open road.
There’s something for every camper and every wallet, whether you’re a boondocker, a seasoned camper, a first time RV owner or a budget traveler.
If you don’t know what you need to look for yet, skip to the next section to learn the most important specifications and buying criteria first. This will make comparing different models easier.
1. Best Overall Shunt Type: Victron BMV-712 Battery Monitor
- Useful readings: voltage, current, amp hours, state of charge, time to go, and power consumption in Watts
- Voltage range 6.5 to 70 volts
- Current range 0 to 500 amps
- Bluetooth connectivity
- Comes with a high quality 500A shunt
- Stores historical data
- Very low current draw
- 5 year warranty
- A bit pricier than other models
Why we love it:
If you are willing to spend a bit more money to get the absolute best RV battery monitor out there that allows you to closely keep an eye on how your house battery is doing, especially if you own a large, expensive battery bank, the Victron BMV-712 will be the best bet. It offers everything you would ever need for monitoring battery health and maximizing battery lifespan.
There are so many things to love about this well rounded battery monitor. Firstly, one thing I love about this unit is that in addition to battery voltage and current, it also shows the amp hours used, which are very crucial during off-grid trips since your RV will not be connected to any electrical hookups.
In addition to the above three basic display options, the Victron BMV-712 series also displays state of charge, how fast the battery is charging, remaining time at the current rate of discharge, and power consumption in Watts. This is useful information that will help you manage and adjust your power usage so that you can prevent over-depleting your battery bank, especially when coupled with the programmable relay function, which allows you to turn off non critical loads or to run a generator when needed.
This selection of information can also help you notice patterns and anything out of the ordinary with your battery as well as your electrical system, especially when coupled with this monitor’s capacity for storing historical data.
A handy feature for remote monitoring of your battery around the clock is Bluetooth connectivity, so that you can check how your battery is doing on Apple or Android smartphones, tablets, macbooks, and other devices.
Another feature that contributes to the Victron BMV-712’s reputation as the best RV power monitoring system for large battery setup is midpoint voltage monitoring. When batteries are connected in series, one bad cell or one bad battery can destroy a large, expensive battery bank. To prevent this, the monitor measures the midpoint voltage to timely detect a bad cell or bad battery and will flash you a timely warning on your smartphone.
In addition to its various readings and useful features, this battery monitor is also extremely easy to install and easy to use. Everything you need is included in the kit, including a high quality 500A shunt and all the necessary fuses and cables. Just connect the shunt to your battery bank, mount it nearby and run the included wire from there to the monitor. You can program visual and audible alarms to your liking. A quick install menu and a detailed setup menu with scrolling texts will help you easily go through the various settings.
Lastly, this battery monitor draws very little power from the battery, with a modest current consumption of only 0.7Ah per month at 12V and 0.6Ah per month at 24V. There’s really nothing you can complain about this literally perfect battery monitor. In case you’re discouraged by the price tag, note that Victron offers an unmatched 5 year warranty for the BMV-712. This battery monitor is often praised for its reliability over the years, so rest assured that you’re getting your money’s worth.
2. Best High Range Shunt Type: Renogy 500A Battery Monitor
- Current range 0 to 500 amps
- Voltage range 10 to 200 volts
- Readings: voltage, current, amp hours used, percentage of charge, power consumption in Watts
- Stores history data
- Includes 500A shunt
- Large display
- 3 year warranty
- Does not offer with Bluetooth connectivity like some competitors at the same price point
Why we love it:
Another excellent solution for monitoring a large and expensive battery bank is the Renogy 500A Battery Monitor. With a wide current range of 0 to 500 amps and wide voltage range of 10 to 200 volts, this model is one of best RV battery monitoring systems for large and versatile battery setups required by campers with more sophisticated energy needs.
Although it does not offer as many handy features as the best selling Victron BMV-712 above, it’s still perfectly sufficient for making sure you’re not over-discharging your precious battery bank as well as for detecting any faults with the battery or your electrical system.
This monitor comes with a larger than average LED backlit display that will tell you the real time battery voltage, current, percentage of charge, power consumption in Watts and also amp hours used, which is particularly useful for the boondockers.
The unit also stores historical data for battery health diagnosis. However, this handy function is undermined by the lack of Bluetooth connectivity, as being able to inspect past data on your smartphone or laptop allows you to more easily make sense of more information. The lack of Bluetooth connectivity is pretty rare for the best battery monitor systems at this price range, so it might be a deal breaker for some RV owners.
Other than this flaw, the Renogy 500A Battery Monitor is accurate, easy to read, easy to install and easy to use. The kit comes with a 500A shunt and all the required fuses and cables for installation and mounting. Another plus is the 3 year warranty, which is longer than the standard 1 year warranty by most competitors.
3. Best All-In-One Shunt Type: bayite DC 6.5-100V 0-100A Digital Power Meter
- Readings: voltage, current, power consumption in Watts and energy in kWh
- Current range 0 to 100 amps
- Voltage range 6.5 to 100 volts
- Stores history data even when turned off
- Reset button
- Overload alarm function
- Includes 100A shunt
- Larger screen
- Consumes little energy
- 1 year free replacement or full refund without return
- Inconvenient recessed pen button
Why we love it:
This unique battery monitor from bayite functions as an ammeter, multimeter, voltmeter and energy meter at the same time. This means you can save some money buying separate meters, and it helps you track the loads and how much power has been used by your electronic appliances. There’s an overload alarm function, where the monitor screen will flash when the draw on the battery exceeds a safe threshold. With this battery monitor, you can better manage and adjust your power consumption to avoid overtaxing your battery bank.
This battery monitor has a decent current range of 0 to 100 amps and a voltage range of 6.5 to 100 volts, which is not the widest range available but still sufficient for most average battery setup. If the previous two models from Victron and Renogy are a bit of an overkill for you, this power meter from bayite might be the best monitor for RV battery for your needs.
One function that I love about this monitor is that it stores history data even when turned off. Unfortunately, this unit does not offer Bluetooth connectivity, or else you would be able to get so much more out of past data for diagnostics.
Other upsides are that the large backlit LED screen is easy to read in all lighting conditions, the kit includes a 100A shunt and everything needed for installation, and this monitor draws very little power from your house battery. This bayite battery monitor comes with a 1 year warranty with free or full refund without you having to return the faulty unit.
Perhaps the only flaw is the recessed pen button, which can be hard to press. Other than that, you’re getting excellent value for money here.
4. Affordable All-In-One Shunt Type: MNJ MOTOR DC Battery Monitor
- Current range 0 to 100 amps
- Voltage range 0 to 200 volts
- 9 reading options: voltage, current, amp hours used, power consumption in Watts, energy in kWh, percentage of charge, running time, internal resistance, external resistance
- Comes with a 100A shunt
- 360° viewing display
- 2 year warranty
- One of the most affordable best sellers
- No Bluetooth connectivity
- No historical data storage (but for under $20, these are to be expected)
Why we love it:
If you’re a budget camper or a first time RV owner, you might not want to spend as much as a hundred dollars on a battery monitor. If so, this super affordable unit from MNJ Motor will be the best battery monitor for RV at its price.
For only about $20, you’re getting a decent current range of 0 to 100 amps and a voltage range of 0 to 200 volts, which offers enough versatility to work with different battery setup. Considering the price, you might expect to get a voltmeter only, but in fact, this little device functions as an all-in-one ammeter, multimeter, voltmeter and energy meter.
In addition to battery voltage, current and amp hours used, this battery monitor also shows power consumption in Watts, energy in kWh, percentage of charge, and running time at the current discharge rate. This will help you gain more insights into when your battery needs charging and keep an eye on your power consumption. All 9 readings are clearly displayed on the 360° viewing LED screen.
Given the price, I was pretty sure that the kit does not include the shunt, but this unit does come with a 100A shunt as well as the fuses and cables for installation. Talking about installation, a handy feature for the novice is the push-on terminal, which makes it easy and convenient to install and remove the wires without the screws.
This affordable battery monitor comes with a 2 year warranty, which is more than what you would expect from such a budget friendly option. As for the downsides, this product does not offer Bluetooth connectivity for remote monitoring and historical data for diagnosis, but that’s to be expected.
5. AiLi Voltage Tester For Caravan RV Motorhome
- Readings: current, voltage, remaining capacity in amp-hours, percentage of charge
- Voltage range 8V to 100V
- Current range 0 to 350A
- Comes with a high quality 100A shunt
- Stores historical data for diagnosis
- No Bluetooth connectivity
- Screen backlight flashes when charging, which might be annoying at night time
Why we love it:
If you have a solar charging system in place, you will love this battery monitor from AiLi. It has a voltage range of 8V to 100V and a current range of 0 to 350A, which is sufficient for most battery setups with a solar system. The kit comes with a high quality 100A shunt and all the fuses and cables required for installation.
This unit shows the number of battery current, voltage, remaining capacity in amp-hours, and percentage of your battery life, as well as showing how many amps are flowing in and out of your battery bank. This is very useful in pinpointing the culprit that is drawing too much power in the system. Another handy feature that contributes to the unit’s ability for diagnosis is that it can store historical data. Unfortunately, it doesn’t have Bluetooth connectivity to make the most of this.
While the models above are the best RV monitor systems in the shunt-based category, below are the more basic and straightforward voltmeters for campers with a smaller battery bank and minimal power consumption, or those who often have access to shore power for charging their house battery.
6. DROK 10-100V Digital Battery Voltmeter
- Readings: voltage, state of charge, battery temperature
- Voltage range 10 to 100V
- Low voltage alert
- Waterproof display
- Removable wiring terminals
- Basic, no current reading or amp hours used
Why we love it:
If you have a simple battery setup and often have access to electrical hookups at the campground, you might be able to monitor your house battery with a basic voltmeter. This DROK voltmeter will be the best battery monitor for RV in its category and overall, a super affordable option that’s easy to use and install.
This voltmeter will show you real time battery voltage and percentage of charge, and you can push the button to change the reading to battery temperature. The voltage range is 10V to 100V, which is sufficient for most average battery setup. The unit is super compact, but it’s no problem seeing the readings on the backlit screen.
Other handy features include the removable wiring terminals that make for fuss-free installation, the waterproof display and low voltage alert that tells you when your battery needs a charge.
For its price, this is a functional unit. It’s pretty basic, with no Bluetooth connectivity and historical data storage, which is expectable. That said, for the same price range, there are still a few, although very rare, other options that offer a bit more useful information on your battery, like the one above from MNJ Motor. For instance, boondockers might prefer a battery monitor that can show them amp hours used and remaining time at the current rate of discharge.
7. Innova 3721 Battery and Charging System Monitor
- Plugs into 12-volt cigarette lighter power point
- Colored LED indicator lights
- Adjustable head
- 1 year warranty
- No current reading, only voltage
Why we love it:
Here’s another excellent voltmeter in case you only need something simple, straightforward and affordable for battery monitoring. What sets the Innova 3721 Battery Monitor apart from competitors is its unique installation. Instead of connecting directly to your RV’s house batteries, it connects to the 12-volt power sockets present inside your RV. The head pivots for easy viewing and angle adjustment.
As a result, it has a fixed voltage reading value of 12 volts. The LCD screen displays the measured voltage with a bar graph to indicate battery charge level and the color-coded LEDs quickly identify the battery’s charge status.
As for the major downside, this monitor does not give you the current reading or any other information on your battery health or your electrical system. Therefore, this entry level battery monitor is more suitable for first time RV owners, those who travel in a small RV with minimal power consumption and those who typically have access to power outlets for charging their house battery.
8. Best Voltmeter for Dual Battery RVs: MICTUNING LED Digital Double Voltmeter
- Shows voltage of main battery pack and auxiliary battery pack at the same time
- Draws minimal power
- Over-current, over-volt and short circuit protection
- Panel flush mount, twist and lock fastener
- Tiny and lightweight but easy to read
Why we love it:
If your RV has a dual battery pack, this super affordable voltmeter will be the best RV power monitor for campers looking for a straightforward unit to monitor battery health. This voltmeter shows you in real time the voltage of the main battery pack and auxiliary battery pack at the same time on the small but easy to read blue LED display.
This MICTUNING battery voltmeter is pretty basic. An extra feature is over-current, over-volt and short circuit protection. Another thing I love about this model is that it draws very little power from the battery. As for installation, this super compact battery voltmeter can be mounted flush on your panel with a fuss free twist and lock mechanism. For less than $20, it does what it’s designed to do and is made to last.
9. Best App-Control Voltmeter: ANCEL BM300 Bluetooth Battery Tester
- Bluetooth connectivity
- Stores historical data
- Reverse-polarity protection, overload circuit breaker, short circuit protection
- No display screen
Why we love it:
If you only need a basic voltmeter but prefer to be able to make sense of more information on your smartphone, check out this awesome BM300 bluetooth RV battery monitor from ANCEL.
With Bluetooth, the free app ANCEL Battery Charge Monitor 12V RV can connect with the battery and do battery voltage test, charging test, cranking test and trip recording on your RV. In addition, the real-time notification will notify you when the battery is at a dangerous discharge rate.
Another useful feature is that this unit can store up to 31 days of data for battery health diagnosis. Other nice additions are reverse-polarity protection, overload circuit breaker, and short circuit protection.
The major flaw with this unit though is the lack of a display screen, so you will need to reach for your smartphone to check how your battery is doing.
10. Most Affordable Voltmeter: ProShopping DC 12V 24V 36V 48V 72V Battery Meter
- Readings: voltage, percentage of charge
- Voltage range: 12V – 84V
- Flash alarm
- Easy to read LCD screen with green backlight
- Screen is waterproof
- Reverse polarity protection
Why we love it:
If you’re on a tight budget or if you’re a first time RV owner, this battery voltmeter from ProShopping might be the best RV battery monitoring system that delivers what it’s made to do at the cheapest price possible.
The waterproof green light LED screen shows two readings: real time battery voltage and the state of charge in percentage. It has a pretty decent voltage range of 12V to 84V, which should be sufficient for basic battery setup. Additional features include flash alarms in case the battery drops to a certain threshold, and reverse polarity protection.
This unit draws very little power from the battery, and you can also turn it off at a push of a button. All in all, it’s budget friendly, functional and easy to use. Nothing special if compared to other models in this list, but absolutely excellent value for money.
How To Choose The Best RV Battery Monitor For Your Budget
An RV battery monitoring system is not an overly complicated piece of machine. Still, pay attention to the following buying criteria when you’re comparing different models, so that you’ll get your money’s worth with a reliable and long lasting product.
As explained above, a voltmeter is cheaper and simpler but not as accurate as shunt-based battery monitors, and doesn’t offer you any additional information as to any fault with the battery or your RV’s electrical system.
Therefore, a voltmeter might be sufficient for campers with a simple battery setup, minimal energy consumption and frequent access to power hookups at RV parks and campgrounds, that is, those who do not need to worry too much about not charging their house batteries in time.
Meanwhile, a shunt-based system would be the best battery monitoring system for RV owners who have a complicated electrical system, for instance one with solar panels and a generator in place to top off the battery on off-grid trips, as well as higher energy consumption using a multitude of electrical devices.
In this case, there is a lot of information you need to be aware of in addition to the percentage of charge your battery has at any given time. This includes whether your battery is charging when you use the generator or the solar system and whether it is charging effectively, whether anything is drawing too much power from the battery, and if the battery is behaving unusually, which might point to fault with the battery or somewhere else within your electrical system.
Display and Reading
As with any display screen really, the larger the better. The battery monitoring system for RV should come with a decent sized LCD screen that’s clear, bright and sharp, and easy to read even in low light conditions.
As for the readings, the screen can display a variety. As mentioned above, it’s best not to discharge the battery down to below 50 percent. As such, the most convenient and fuss-free reading with regards to a battery’s state of charge is as a percentage. For instance, if the display shows 65 percent, you know immediately that you need to charge the battery bank soon.
Another useful reading is the amp hour meter. It measures the current going to the battery and from the battery to everything else that uses its power. Therefore, it can help you become aware of how power consuming an appliance is, and if something is wasting energy. This is particularly handy when you’re boondocking and do not have access to a campground’s electrical hookups.
Some of the best RV battery monitor systems can also show you the battery’s temperature to prevent overheating, as well as notify you of any possible battery failure or if there’s something wrong with any connection. While a small LCD display might not be able to tell you everything at a time, the units with Bluetooth connectivity can tell you more.
Current Range and Voltage Range
As above, voltmeters only read battery voltage, while shunt based monitors can also give you current readings. You should also check the range of such readings when comparing different battery monitors. In general, the wider the range, the more versatility for different battery setup.
For current readings, most entry-level models only read 0 to 100 amps of current output, while the best monitors for RV battery can read up to 500 amps of current output. As for voltage readings, some of the common ranges include 6.5 to 70 volts, 6.5 to 100 volts, 10 to 120 volts, while the best battery monitor for RV can read 0 to 200 volts.
To offer convenient remote monitoring, the best 12 volt battery monitoring system these days often offers a handy feature, that is bluetooth connectivity.
You can use a bluetooth-enabled companion app on your smartphone to check the status of your battery. This also allows you to get much more details on your battery’s health than from the monitor’s display.
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Even when you forget to check the battery monitor’s screen regularly, the best battery monitor for RV would flash an alert on the display screen when the battery is discharged to a dangerously low level.
For instance, some models will tell you to turn on the generator when the battery gets below 50 percent.
If you use Bluetooth connectivity for remote monitoring, you will receive an alert on your smartphone telling you that your battery is running low on juice.
The best RV battery monitoring systems can even give you a summary of important past data, including the number of charging cycles, total discharges, and patterns that will point to the culprits having been wastefully exhausting the battery’s power.
This is extremely useful in diagnosing the battery’s state of health and helps you determine when your battery needs to be replaced.
If you’re dealing with a small and simple house battery setup, a battery monitor that plugs directly into a 12 volt charging outlet inside your rig might be sufficient. However, for larger and more complicated battery setup, your best option is to connect the battery monitor with the battery using shunts, wires, clamps, and other included accessories.
For ease of installation, remember to check if your RV battery monitor kit comes with the necessary fuses and cables used to connect the battery and the shunt to the monitor. The shunt’s role is to measure in real time the current that is going in and out the battery, which the monitor will use to calculate the battery’s current state of charge as a percentage of total battery capacity.
Lifespan and Warranty
The best way and perhaps the only sensible way to get an idea of how long a certain battery monitor might last is to take some time browsing through the reviews. In addition, the length of the manufacturer’s warranty does speak some for a product’s reliability.
While most RV battery monitors on the market these days come with a standard 1 year limited warranty, the best RV power monitoring systems of the bunch often offer a 3 year warranty, while a few rarer cases come with a 5 year warranty.
12V Battery Monitors: FAQs
What are the best RV battery monitor brands?
The market for the battery monitors is vast and diverse with many new entrants, but the best brands of RV battery monitor with tried and true best selling products include Victron, Renogy, Bayite, ANCEL, AiLi, MNJ, MICTUNING, Xantrex, Simarine Pico and DROK.
Their products are popular, so there will be more reviews for you to base your decision on. They also offer satisfactory warranty and responsive technical support.
How accurate are RV battery monitors?
There are two types of RV battery monitor systems: voltage-based systems and shunt-based systems. Battery monitors that rely on shunts are more accurate. They cost a bit more than the simple voltage-based type, but it’s totally worth it.
Voltage-based battery monitors measure battery voltage in real time but can only estimate the state of charge based on voltage. This is not very accurate as voltage can fluctuate with changes in temperatures and humidity. This type of battery monitor can even produce slightly different results with two similar house battery banks.
Meanwhile, shunt-based systems use a special device called a shunt, which is installed between the battery and all the electrical systems and devices that consume power from the battery. The shunt measures in real time the amount of current coming in and out of the battery.
It then uses this information to calculate the amount of charge left in the battery, which allows for battery accuracy then calculations based on battery voltage. The shunt also uses this data to calculate the power unit’s average and running energy consumption and projected remaining battery runtime.
How do I install an RV battery monitor?
You must absolutely follow your user’s manual religiously as this involves fuses and cables and many accessories, which can be complicated for the novice. But here’s the basic principle of connecting a battery monitor to your RV system:
The best RV battery monitor kits these days typically come with the shunt included, along with all the required fuses and cables for wiring it with the battery and your RV’s electrical system. First, connect the shunt to the negative terminal of your battery and keep it securely on that side of the battery.
Then, connect every negative connection of your RV’s electrical system to the shunt. In case they can’t all fit, use a bus bar. Always remember that the shunt is the only thing that should be connected to the negative side of your house battery. Now you only need to connect the control cable and the monitor LED display.