What Is A Campervan Power Management System & Do You Really Need One?

Graham Bogie

A campervan power management system is a great way to keep an eye on your RV, motorhome, or campervan while you are away.

Not only does it give you peace of mind, but it can also help you catch minor problems before they turn into big ones.

If you are considering purchasing a power management system for your camper, here’s everything you need to know.

What Is A Campervan Power Management System?

An campervan power management system is a centralized control and monitoring solution. 

It allows you to manage and monitor the power consumption in your vehicle, so you can avoid overloading the electrical system and causing damage.

The control panel or mobile app displays real-time information about how much power is supplied and used by a device, so you can make adjustments as needed.

It also has safety features that will shut off power to certain appliances if they draw too much electricity.

This prevents damage to your electrical system and keeps you safe while on the road.

One of the main benefits is that it allows you to actively manage the demand on your battery bank based on the available supply and real-time load.

But it’s more than just a power management system. You can monitor all your onboard systems with suitable sensors, like liquid levels and multiple temperature settings.

How Does A Power Management System Compare To A Battery Monitor?

A battery monitor is a simple device that tells you how much charge is left in your batteries. If the battery is being charged, it will indicate the charging state.

It doesn’t allow you to control the power usage in your RV or campervan. However, they are a low-cost option for basic monitoring. 

A basic battery monitor doesn’t allow you to actively manage your entire electrical system, nor do most support remote monitoring.

A power management system (PMS) takes active management to a whole other level. 

In a regular electrical system, some components include basic monitoring. 

For example, many solar charge controllers display the real-time input from the solar panels, and a basic 12v battery monitor indicates the charging state of the battery bank.

But you need to monitor those readouts, recognize when adjustments are needed, and take appropriate action to ensure you don’t run out of power.

With a high-end monitoring system, it’s possible to monitor devices and appliances supplying and using power.

Major PMS suppliers have moved towards a centralized monitoring system and display. That means all the information you need is available in a single control panel.

What’s more, many of those control panels are now available via a mobile app. 

That means you can access all the necessary information without installing more electrical equipment. It may not be integrated or centralized, but it is available.

The best PMSs communicate via Bluetooth. So, when you’re in or near your camper, the PMS will send the information to your mobile device. 

So long as the PMS is connected to an internet connection, you can manage your camper’s systems remotely. Even from the other side of the world. 

Don’t forget this will use energy, so your batteries will flatten if no charging is connected! 

How Does A Campervan Power Management System Work?

Geek alert! This section is a teeny bit techie.

A camper’s power management system operates with three main components:

  • Sensors to monitor the services
  • Acceptable operating parameters 
  • Actions that trigger when acceptable operating parameters are breached

Sensors

A sensor is needed for each system parameter the PMS monitors and manages. Then, it feeds information back to the control panel in real-time.

In principle, there are two types of sensors: 

  • those that operate on a fixed resistor, and 
  • those that operate on a variable resistor.

Variable resistors are usually some form of voltmeter. They all use the fundamental principle of measuring a change in voltage between 2 points on a variable resistor. 

For example, they can measure:

  • voltage,
  • temperature,
  • liquid levels.

For liquid levels, a float moves up and down a resistor. The control panel translates the sensors’ voltage difference across that resistor into a scale on the control panel, so you understand how empty or full that tank is. 

For temperature readings, a heat-sensing pointer changes the value of the variable resistor as the temperature fluctuates. That voltage value is then translated into a temperature scale on the control panel.

These are ideal for monitoring your fridge or camper’s ambient temperature.

For current readings, for example, monitoring energy consumption, the sensors use a fixed resistor, sometimes called a shunt. 

The voltage driven by changes to current is translated on the control panel, so you understand how much energy you’re using at a given time.

Acceptable Operating Parameters

The sensors alone monitor the systems and relay the information back to the control panel.

To help you make necessary adjustments, the system needs to be configured to understand acceptable operating parameters.

For example:

  • What the temperature range is for charging a lithium battery,
  • Normal operating voltage of the battery,
  • Energy consumption from the battery bank,
  • Energy being harvested from the solar array.

Rules & Actions

So, now with the sensors monitoring your camper’s systems and the PMS configured with what “normal” looks like, the most intelligent feature of the power management system kicks in: the rules and actions.

The management system will take corrective action if these parameters reach pre-set levels. 

For example, it may open a power breaker to prevent energy from being used if the system voltage has dropped to a low level. 

Or auto-switching to a new power supply to charge the battery bank. 

To illustrate the art of the possible, you could configure a power management system to turn on your generator when your energy consumption is higher than your charging rate. If you continue at that level, you will have a flat battery in an hour.

A word of warning, though. Not all the power management systems available are that clever (yet). So you will need to look at the capabilities of each device to ascertain if it will meet your needs.

More on that below.

Why Do You Need One?

In its simplest form, you don’t need one. But there are some snazzy benefits to these devices.

Convenience

All the primary systems have simple meters and dials to give you the most basic information while you’re in your camper. 

However, these meters are not always conveniently located. 

For example, our water tank level is on the driver’s seat base. 

The battery indicator is in the main cabin, and the MPPT is on the passenger seat box at floor level, so I need to get on my aging knees to read the data. 

All doable, but not very convenient. 

With a power management system, I can install the centralized control panel conveniently or have access to it on my mobile device.

Troubleshooting Assistant

Secondly, we can access our historical data. So what?, you may ask. We did too!

Well, it’s interesting, isn’t it?

If you’re anything like us, the first thing you look at when you return to your camper after a day out is the battery levels. We don’t even think about it anymore. It’s like 2nd nature.

We don’t even notice we’ve looked unless there is something that may appear untoward.

Then we talk through what might have been going on:

  • Was there enough sunshine on our solar panels? 
  • Did we inadvertently leave a laptop charging through the inverter?
  • Are the batteries ok, or are they reaching the end of their usable life?

We don’t need to guess much with access to the historical data. 

The power management system may tell us how much power the solar panels provide during the day and how much energy is consumed.

That will give a clear indication if, or where, we have a problem.

For example: 

  • Suppose the system didn’t generate much from solar. In that case, you can check if that’s weather or shade related or an issue with your MPPT controller or solar panels.
  • If you had a lot more load running than normal (the historical data will tell you what “normal” is), then perhaps you left an appliance switched on or had a sudden parasitic drain.
  • If your supply and load are within the expected parameters based on your historical use, perhaps you have a problem with the battery.

The historical data provides you with enough information to start looking at the right part of the system for the problem.

Remote Monitoring

Victron VRM
Source: Victron

Finally, if and when we leave the van for a few days, we have no means of monitoring the health of the camper’s system.

We leave the solar connected to the battery bank but isolate the battery outputs. Without a remote battery management system, we have no idea if there are any problems. 

If we expect to be away for long periods, we switch all inputs and outputs off, and we’re entirely in the dark. 

If we had a battery management system installed, we would be forewarned of any problems. At best, we could take action to prevent or minimize further problems. 

Let’s say the battery was depleting faster than we would expect. We could remotely switch off appliances and reduce the load.

Then, armed with the data indicating a problem, we can bring a replacement component. Or delay visiting the grocery store to fill the fridge that can’t run on flat batteries.

Knowledge is power, as they say.

Pros & Cons Of A Remote Monitoring System

There’s a lot of hype about these types of products. However, you only need to spend a few minutes on the Facebook groups to hear about the “best in class Victron Cerbo.” 

We’ve done a lot of research and reflected on what these components currently do, and more importantly what they don’t. 

In another post, we’ve written a more detailed overview of the top three monitoring systems for motorhomes, van conversions, and RVs. 

So here, we’ve provided a high-level, generic overview of their advantages and disadvantages.

Pros

  • You can monitor and control your camper’s systems to confirm that everything is healthy.
  • Nearly all management systems now use remote management via a Smartphone App.
  • They display all system readings in one central location for convenience.
  • You get visual alerts for any system failings.
  • Battery, tank & temperature monitoring.
  • Butane & propane level monitoring.
  • Service data display.
  • Some systems allow you to control various functions remotely.
  • Some systems carry out preemptive and corrective actions to protect the power system.
  • They give the camper an upmarket feel.
  • Retains historical data.

Cons

  • They can be expensive to install.
  • Some systems only work with their own brand products.
  • Some systems do not have all the sensors to monitor the main camper components.
  • Retrofitting can be difficult. You need access to all critical components and route connections along existing cable runs. 
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Best Campervan Power Management System

There are four leading providers of power management systems for RV and campers:

  • Victron Cerbo
  • Renogy One
  • Simarine Pico & Caravan Control Panel
  • RV Whisper

However, these monitoring systems vary enormously in their functionality. Trying to figure out their capabilities from the manufacturers marketing materials is quite the task!

In Conclusion

Having a good understanding of your energy usage is critical to boondocking for long periods. It enables you to make the best use of your resources and avoid nasty surprises.

Using a campervan power management system, you can see what is going on in your camper’s systems. That will allow you to take the necessary actions to prevent any issues.

With a sound management system in place, you’ll be able to monitor your power usage, tank levels, and more from anywhere in the world.

So even if you’re away from your camper for an extended period, you can rest assured that everything is running smoothly.

Do you monitor your RV or campervan’s power usage? What method do you use? Let us know in the comments below.

Graham Bogie

Graham Bogie - Expert in RV & Campervan Electrics - Mowgli Adventures

Graham is a seasoned marine electrical engineer with two decades of experience designing customized electrical systems for plant machinery and converting campers and overland vehicles. His expertise has led him to author the reputable Campervan Electrics Handbook and become the chief designer of the RV Wiring Design Tool. As a knowledgeable figure in the field, his YouTube channel, blog, Facebook group, and newsletter, offering electrical advice and product reviews, reach more than a million users each year.

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