Properly Monitoring Your RV Batteries for Off-Grid Camping

Many RV campsites in state parks and national parks don’t have electrical hookups, so knowing if your batteries will get you through a 2 or 3-day weekend camping trip is pretty important to help keep it a fun and safe trip for you and your family.

For many people, off-grid RV camping for a week or more is an enjoyable way for them to use their RV. Camping in a secluded area is more peaceful than a campsite with closer neighbors.

But, an off-grid camping trip in your RV can quickly turn into a bad experience if you are not prepared and run out of propane and/or battery power. For example, imagine going on a week-long RV camping trip into the middle of nowhere and waking up to freezing cold temperatures inside your RV at 3:00 in the morning on the second night. This is one reason why you should monitor your propane levels. Many RV owners have had this happen to them (usually only once) – and that event is never forgotten.

As important as it is to monitor your propane levels, even more critical is monitoring your RV house battery’s state of charge (SOC) – not just the battery’s voltage, but the actual state of charge as in 50%, 75%, or 100% SOC. You will need to make sure that your batteries get sufficiently recharged every day or two on your off-grid camping trip for pretty much everything to keep working in your RV including your lights, refrigerator, and propane furnace. If your RV has a built-in generator, it even uses your RV house batteries to start it.

If your RV house batteries run out of charge (0% SOC) during one of your off-grid RV trips, then it is more than just “lights out”. You will have no heat from your propane furnace, no refrigerator so possibly spoiled food, no water pump so no running water if you don’t have a water hookup site. And if this were to happen when you still have a few days left on your trip, then your vacation plans probably just got changed.

If you are not able to accurately monitor the SOC of your RV house batteries, then you don’t really know if your solar and/or generator are adequately charging your batteries. And you don’t know if (and how much) you need to conserve your battery power. If you use a generator to charge your batteries, you won’t know if you are running your generator too much or too little to get through your trip.

Monitoring the SOC of your RV house batteries helps you more confidently enjoy your off-grid camping trips.

RV Battery Monitoring When You are Off the Grid

Being able to monitor the state of charge (SOC) of your RV house batteries while you are camping off the grid will help you to know how much energy you need to get through your trip. But unfortunately, accurately monitoring battery SOC is a little more complicated than monitoring something like a propane tank.

Propane is easy to measure. Accurately measuring how much energy is left in a propane tank can be done in several ways. For example, propane sensors from Mopeka can be placed on the bottom of the tank to measure the height of the propane level and show the percentage of propane that is remaining. The Mopeka propane sensors also integrate with the RV Whisper Monitor Station to provide easy graphing of historical data so you can see how much propane your RV uses on a cold night.

You can also get a rough idea of how much propane you have left by how heavy the tank is. If you have a scale, you can weigh the tank and get a more accurate measurement of how much propane is in the tank. Basically, there are several ways to accurately measure how much propane is left in a propane tank or cylinder.

Unfortunately, measuring the amount of energy (SOC) the battery has left is not so easy. You cannot weigh a battery to find out its SOC. Measuring just the battery voltage is not an accurate way of getting the SOC. There are numerous variables that make a simple battery voltage reading an inaccurate way to measure SOC. The variables include the temperature of the batteries, the type of batteries, whether the battery is being charged or is in use, and many others.

The best way to obtain an accurate measurement of your battery’s state of charge is by using a “shunt-based battery sensor”. A shunt is a precision resistor that gets wired into your battery cables and measures how much electricity flows into and out of the battery.  A “shunt-based battery sensor” is an electronic device that connects to the shunt to measure how much current is flowing in and out of the batteries, allowing it to calculate an accurate SOC.

A shunt connects to one of the battery cables that is connected to one of the battery terminals. The shunt essentially becomes a part of the battery cable or a short “extension cord” of the battery cable. Every amp of electrical current that goes into and out of the battery bank flows through the shunt.

The battery sensor uses the shunt-based current measurements (Amps) along with battery voltage (Volts) to calculate an accurate battery SOC. Shunt-based solutions are the gold standard for monitoring an RV battery’s state of charge.

Some modern Lithium Iron Phosphate (LiFePO4) batteries even come with an internal built-in shunt-based battery sensor that communicates with a bluetooth phone app to measure and display an accurate SOC – for that single battery. If you want to monitor the SOC of a battery bank made of multiple Lithium batteries, you can still use a single external shunt to measure the SOC of the entire battery bank.

Shunt-Based Battery Sensors Plus RV Whisper Monitoring: The Protection You Need to Get the Most Out of Your Off-Grid Camping Trip

With a shunt-based battery sensor attached to your battery cable, you will be able to obtain the most accurate reading of your battery’s state of charge. And if you use a shunt-based battery sensor that you can add to your RV Whisper Monitor Station your RV batteries SOC, volts, and amps will be logged every few minutes so you are able to easily see both current data and graphs of historical data that to help ensure that you will have enough battery energy to get through your entire camping trip.

The RV Whisper Monitor Station currently works with two of the top shunt-based bluetooth battery sensors on the market: the Victron SmartShunt and the Thornwave Powermon / DC Power Meter. Both of these shunt-based battery sensors come with a bluetooth phone app so you can see your batteries SOC on your phone when you are in your RV.

They can both also be easily added as a bluetooth battery sensor to your RV Whisper Monitoring Station to provide you with detailed SOC information about your batteries including being able to see the data over the internet. When added to your RV Whisper Monitor Station you can see on your phone or computer:

  • How full the battery is, expressed in a percentage from 0% to 100% SOC
  • How many amps are going into and out of the battery at various times of the day.
  • All battery monitoring data (volts, amps, SOC) is logged every five minutes, and easily displays graphs and trends that allow you to accurately track battery usage over a trip whether it is a 3-day event or a weeks-long vacation.
  • The ability to receive email and text alerts when the battery is getting low (based on pre-set thresholds that are set by the user).

You also have the ability to add other bluetooth wireless sensors to your RV Whisper Monitor Station including:

With adding one of the shunt-based battery sensors to your RV Whisper Monitor Station, you will be able to see critical data, such as how fast electricity goes into and out of the battery (amps) when it is on a charger, how much batteries discharge overnight before the sun comes up (very useful if you are relying heavily on solar power to keep the battery charged), and many others.

The data you obtain from the RV Whisper Monitor Station allows you to adjust your activities during the course of your trip and do what you need to do to preserve your battery power. This gives you the peace of mind you need to fully enjoy your trip knowing that your battery is not going to run out of charge at an inopportune time.

Bluetooth Radio Signal Optimization in RVs

The RV Whisper Monitor Station (RVM1 or RVM2) collects data from sensors in the RV using Bluetooth radio signals. The RV Whisper Monitor Station must be able to see the Bluetooth radio signal of the sensors that are placed in different areas of the RV in order to work properly. In most RVs, the Bluetooth communications work just fine and there are no problems collecting data from the sensors.

However, after initial setup, some RVs have trouble with the Bluetooth signal between one or two sensors and the RV Whisper Monitor Station. This tends to happen most often in larger and heavier RVs like some Super-C RVs and 40+ foot Class A diesel pushers. Problems have also been known to occur in fifth-wheel trailers, particularly with the battery sensors.

The good news is that issues with these “problem sensors” can usually be resolved by moving the RV Whisper Monitor Station and/or some sensors to get all of the sensors to work reliably in the RV.  This document provides information on how you can “tune the location” of your RV Whisper components to achieve reliable sensor readings.

How Does Bluetooth Work?

Bluetooth is a wireless technology that uses low-power, short-range radio signals to allow two devices to communicate with each other. When there is adequate radio signal strength (between the two devices) the devices can see each other’s radio signal. This lets the devices communicate with each other in a reliable way.


What Causes a Poor Bluetooth Signal in RVs?

As we touched on earlier, on the rare occasion that Bluetooth radio signal strength problems prevent a sensor from “working” in an RV, they tend to happen more often in larger and heavier RVs. Bluetooth radio signals have the longest range (up to 400 feet) when there is a direct line of sight with no objects between the two devices. When objects like RV walls, doors, floors, countertops, and cabinets are between any one sensor and the RV Whisper monitor station they all degrade the radio signal strength to some extent. In most RVs, this is not a problem.

Walls, floors, and doors in larger and heavier RVs are usually more solid which impacts the Bluetooth radio signal strength more. These heavier RVs might also have marble or granite countertops, ceramic floor tiles, stainless steel appliances, and solid wood cabinets. Sensor troubles due to low Bluetooth radio signal strength usually occur because multiple objects are between the “problem sensor” and the RV Whisper Monitor Station. Each of the objects between the devices reduces the radio signal strength some amount. When there are more objects in the “line of sight” between a sensor and the RV Whisper Monitor Station, the radio signal strength can be reduced enough to prevent the sensor from connecting with the RV Whisper monitoring station.


Battery Sensor Quick Tip

If you are having trouble with a battery sensor (like the BV2 or BMRV1 sensors), make sure the battery sensor is placed so that the batteries themselves are not in the “line of sight” between the sensor and the Monitor Station. Moving the sensor just a few inches so it is on top of the batteries can have a dramatic effect on improving the Radio Signal Strength for that sensor.


How to Optimize the Bluetooth Radio Signal in Your RV

If you are having trouble with the Bluetooth connections between the RV Whisper monitoring station and one of your sensors, it is usually a very easy fix. Most often, all that is needed to optimize the Bluetooth radio signal is to move the sensor and/or the Monitor Station. In many cases, just moving the sensor or Monitor Station a few inches can eliminate an obstructing object or two and establish a strong Bluetooth connection.

To start with, visualize what’s between the RV Whisper monitoring station and the sensor. Picture the “line of sight” between the two devices and identify all obstructing objects. Then move the sensor in whatever direction needed to establish a clearer line of sight.

Often, you might need to move the Monitor Station to a better location, depending on what is blocking the signal. For example, in larger RVs, the Monitor Station might need to be relocated towards the middle of the vehicle in order to send a strong enough signal to all of the sensors. Or, you may need to move the Monitor Station to be closer to (perhaps directly above) the battery compartment if your battery sensors are having Radio Signal Strength problems.


How Do I Know if I Have an Adequate Bluetooth Connection?

There is excellent data available to you in the RV Whisper application to help you resolve sensor location issues. The RV Whisper Monitor Station looks for Bluetooth sensor data every five minutes and logs the data along with a timestamp. One of the data points that is logged is the Bluetooth Radio Signal Strength Indicator (RSSI).  You can see the RSSI values displayed in one of the data graphs for each sensor. The RSSI graphs let you see the impact of moving a sensor or the Monitor Station helping you “fine-tune” the ideal locations to get all sensors working reliably in your RV.


When the RSSI value is at -75 dB or better (e.g., -70 or -65) then you have a very strong Bluetooth radio signal. When the RSSI value is at -95 dB or worse (e.g., -100 dB or as bad as -105 dB), then you have a weak Bluetooth signal and probably have missing data from that sensor. Another possible indicator that the Bluetooth signal is weak is when the monitoring system goes longer than five minutes between logging data points. After changing locations, it is best to wait up to an hour before looking at the RSSI graphs for each sensor. Comparing “before” and “after” RSSI values should help you quickly find the sweet spot for your sensors and Monitor Station.

If you cannot see any data at all from a sensor, then there is a possibility that the sensor might not be working at all. If you believe this might be the case, temporarily move the sensor to a countertop or someplace close to the monitoring station, or temporarily move the Monitor Station to be very close to the sensor. Wait 20 minutes or so to make sure it works and that the monitoring station is picking up sensor data. Then slowly move the sensor to where you want it and monitor the RSSI graphs for that sensor after each placement.

If you are still unable to optimize the Bluetooth radio signal between your RV Whisper monitoring station and one of the sensors even after moving the sensor and/or station to different locations, contact our technical support (support at for further assistance.

RV Monitoring When Your RV is in Storage

As we get into the winter months, more RVers will be storing their vehicles off-site. If you are planning to put your RV in storage for the winter, you will want to be sure that it is secure, and that it is ready to go if you decide to take it out during the cold season.

If you store your RV off-site year round, you will want to monitor it for security in the storage lot and to know if it is ready to go before you start your next trip.

If you are one of those who works full-time and you are on a busy schedule, you no doubt look forward to that precious time that you are able to take to get away from the rest of the world and enjoy your RV. Maybe you are planning to take it out for an extended weekend, or maybe you are going to take it out for a week or two and spend some quality family time over the holidays.

However you plan to use your RV, it is important that you are able to closely monitor everything that is going on with it, so you will know if it is properly prepared to take out for your next trip. As any seasoned RVer can tell you, there are plenty of things to check in your RV before starting a trip; and if these checks can’t be made ahead of time, they can result in surprise delays and headaches that can ruin your schedule and cause you to start your trip on the wrong foot. 

A comprehensive monitoring system like RV Whisper can give you peace of mind knowing that your RV is ready to go when you are.  Our wireless monitoring system is always on, and it provides remote visibility into the status of your RV so you can Know Before You Go.

Taking your RV Out of Storage

Here are some of the important things that you may want to monitor when your RV is in storage – so you can ensure that you will not encounter delays from these items when you take your vehicle out:

Is Your Propane Full?

You may or may not be using your propane while your RV is in storage. This depends largely on whether or not the storage facility has shore power and other specific factors. For example, you may be using your propane to keep your refrigerator cold when it is not plugged into shore power. Even if your facility does have shore power, power outages are all too common, and in the event that this happens, your propane may be used as a backup to keep the fridge and freezer cold.

The key question when you are storing your RV off-site and plan to take it out is – do you have enough propane to get you through your trip? Because when you are camping out in the middle of nowhere on a cold winter night, the last thing you want is to run out of propane at 2 o’clock in the morning. You will need to closely monitor your propane levels while your RV is in storage so this does not happen to you.

Are Any of Your Tires Low on Air?

When you are on a tight schedule, your whole schedule can be thrown out of whack if you discover a flat tire. Worse yet, a low tire can cause a tire blowout after you hit the road, which jeopardizes the safety of those you are traveling with and others on the roadways..

Stay on schedule and prevent serious tire-related RV accidents by continuously monitoring the pressure on each of the vehicle tires, even when in storage. It is very important to have real-time data that tells you (while driving) if your tire pressure and temperature change from the safe range. It is also very helpful to know if you have a slow leak in one of your tires while in storage.

This level of detailed information helps you better determine how to deal with issues that you may have with your tires. For example, a very slow drop in tire pressure might only require that you fill it up with air before you leave on your trip. However, a faster leak might indicate a more serious problem, which could require that the leak be patched or that the tire be replaced.

Are Your Batteries Fully Charged?

Another frustrating scenario is when you are taking your RV out on a trip and you discover a dead battery. When batteries get drained below a certain point, it can shorten their lifespan, and winter weather can also cause a partially charged battery to freeze faster. Trailer brakes require a charged battery for them to operate safely. Finding out you have to charge and/or replace a battery at the very beginning of a trip is one way to get your trip started on the wrong foot.

If your storage facility has shore power or you have solar panels to keep your RV batteries charged, you will want to know in advance if they are working properly. Did your RV have reliable shore power the whole time that it was in storage? Did your solar system keep your batteries charged up? If so, then your battery will probably be fully charged. But this might not be the case if your shore power was out for a while, or if snow covered your solar panels for a few days. You will want to know before you start your trip so you can deal with any resulting problems with the battery in advance.

Do You Need to Fill Your Fresh Water Tank? Or Empty your Gray and Black Tanks?

When you are getting ready to take your RV out, you need to make sure you have enough water for activities like cooking, bathing and washing dishes. And perhaps you may need to dump your Gray and Black tanks because you weren’t able to do that after your last trip. Some RVers keep their Fresh water tank filled while the vehicle is in storage, while others drain them. However you deal with your water tanks, knowing their status before you start your trip can eliminate unwanted surprises.

Are Your Refrigerator and Freezer Cold?

Do you leave food and/or condiments in the refrigerator and/or freezer when you put your RV in storage? If so, you will want to know if that food is still safe to eat before you start your next trip. In many cases, this will depend on whether the food has remained refrigerated or frozen during the time that has been in storage. In this scenario, it is especially important to have an RV monitoring system that gives you historical data with timestamps that tell you when and for how long your refrigerator/freezer was not working.

Receiving email and text alerts if the RV fridge or freezer temperature operates in the food safety danger zone can keep your family healthy during your RV trip.

Has There Been Any Water Leakage?

When you have an RV that has running water, leaks are always a possibility. This can happen because of pipes freezing, poorly connected pipes, leaky toilets, and similar issues. Water leakage can lead to even bigger problems such as mold and mildew, which is unhealthy and very expensive to clean up.

Keep close tabs on the areas that are prone to leakage (such as under bathroom and kitchen sinks, and under the water heater) and receive alerts as soon as any leaks are detected. A quality monitoring system like RV Whisper can tell you when the leak started and how long it has been going on, so you can act accordingly.

Cold Weather RV Storage & RV Use

When you are storing your RV in cold weather, you will need to decide whether or not it makes sense for you to winterize it. If you are storing your vehicle for the entire winter and not planning to take it out at all, then winterizing probably makes sense – especially if you live in a very cold climate. If, on the other hand, you are planning to take your RV out every other weekend, then winterizing may not be your best option.

Here are some tips for those who are planning to winterize RVs:

  • Make sure your water system is completely drained and/or has non-toxic RV antifreeze everywhere. Any water that is left in the plumbing system can freeze and cause cracks in the pipes.
  • Monitor your tire pressures. As we talked about earlier, tires may lose pressure during winter storage, so keep a close eye on your tire pressure and inflate them to the proper level before taking the RV out again.
  • Protect your battery. Again as discussed earlier, one of the greatest frustrations RVers can face is finding out that their battery died while their vehicle was in storage. Be sure to closely monitor your battery voltage, and if for any reason the charge is getting low, take steps to get the battery fully charged again.

If you are not winterizing your RV and it will be stored or used in weather that can get below freezing, they you need to:

  • Monitor Temperature in RV Wet Bay area. Many RVs have a “wet bay” area where the fresh water hose is connected and water valves are located. These are often the first places to freeze because they are likely not heated.
  • Monitor Temperature near Water Heater. If the water heater is not working for any reason (turned off, no shore power, no propane) then it can freeze and become an expensive repair problem.
  • Monitor Temperature near Water pump. The RV water pump and especially the small filter attached to most pumps is susceptible to freezing and creating a slow leak that can be very damaging if undetected for a long time.
  • Monitor Temperature in living area. The indoor plumbing (sinks, shower, toilet) are all subject to freezing damage if they get too cold for too long.
  • Monitor shore power, batteries, propane. Your RV may depend on shore power, propane and/or your batteries to keep your water lines from freezing.  Knowing if any of these critical items are working properly can prevent expensive water damage and the frustration of plumbing repairs at the beginning of your RV Trip.

RV Security in Storage

Of course, security is extremely important when you put your RV into storage. If you are storing your recreational vehicle away from home, the first thing you want to do is to choose your storage location wisely. Look for a facility that is highly reputable and has good security. For example, your storage location should have a number of different cameras throughout the facility that are monitored regularly, and the facility should restrict entry to other users who have a code.

Finding a secure location in which to store your RV is only half the battle, however. We all know that those who monitor the facility can only do so much to stop a vandal or a thief. To ensure that your RV is fully secure, you will need to have your own monitoring system as well.

RV whisper provides the ideal solution for securing your recreational vehicle while in storage. Our monitoring system has motion sensors and door open/close sensors that can alert you by text or email whenever there is a breach. The alerts come in within just a few seconds of the monitored activity, allowing you to take immediate steps to secure your RV whenever there is any concerning activity occurring.

Know Before You Go

Monitoring your RV while it is in storage brings peace of mind. Knowing the status of your tires, propane tanks, water tanks, batteries, shore power, plumbing temperatures, fridge temperatures and more, helps you start more of your RV trips “on the right foot”.  Of course many surprises are fun, but a surprise that delays the start of your next RV trip is not one of them.