RV Battery Monitor Upgrade

A good Battery Monitor is an amazing device that can provide vital information and function. The BMV-712  from Victron was my favorite until the Victron Smart Shunt came out. It’s very similar to the BMV -712 but without the hardwire display. I never used the display and the Smart Shunt is a little cheaper. Our original stock battery monitor was a voltage based monitor and it felt like I was always guessing what the state of charge actually was. The reason the state of charge method was inaccurate  was that only works if your battery can rest to give an accurate reading. For example, if you are charging the battery the voltage will rise and give a false sense that your battery is charged more than it is as well as when you are using your battery, some kind of a draw on it the voltage will drop giving you the impression the battery is more depleted than it is. As you let the battery rest the voltage will give an accurate reading but when you are using your RV that is the most critical time to find out the state of your battery. 

The BMV-712 is a shunt based system to measure everything that goes into your battery and everything that goes out. When installing the shunt it’s important to remember the shunt is the only thing connected to the negative side of the battery. If any thing else is connected to the battery it will not be measured by the Battery Monitor.  The thing I also like about it is the ability to have it grow with your system as upgrades are made. It will work with any battery type, so if you start off with it on your current lead acid battery and choose to later upgrade to AGM or Lithium it can handle all of that. Also it has a 500 amp shunt so it can handle the bigger inverters that RVers love. 3000 watts is usually on the larger side for inverters and it is more than capable of handling that. I also appreciate a good app and the app they have developed for this works well and makes changing the settings just about as easy as you could imagine.  

Option 2

If you need something that is more budget-friendly I have a few options for you and a little bit of help on how to setup the most budget friendly one. The first one is a simple battery monitor  with a 100 amp shunt. There are different ways you can set this one up, I will show you how to set it up with a switch so you can see how much is coming in and switch it to how much is going out. If you want to wire the switch you can get the switch from amazon here and wire it up like I did here. Some prefer to install two on one shunt to have one showing the in and one showing the out. By the time you install two monitors like that you might as well look at the next option for close to $30

Option 3

The third has a completely different type of sensor that now has the ability to calculate the difference between amps coming in and going out which is a big step up doing the math for you so you don’t have to babysit the system. The sensor is also a step up to 200 amps so it is better as your system grows. This option might be the most simple of setups also as the sensor goes around the wire rather than having to install a shunt with an additional connection.

Option 4

The 4th option has up to a 350 amp shunt for the larger systems with a good size inverter but it’s not as customizable as the BMV-712.  It is the AiLi Battery Monitor and has a few different price point options for you depending on the size of shunt you might want. Many complain about the difficulty of setting it up and getting it to learn the capacity of the system. It’s worth a look if you are trying to keep cost down and don’t care about the customization or the bluetooth functions. 

Any of these monitor options will be an upgrade if you currently have a voltage based monitor, just pick the one that fits your needs and budget!