Power meters: know what you are using!

Most RV come with standards displays that tell you how much battery left there is using a fairly rigid scale of three led lights. 

These primitive control panel may seem enough for most, but I wanted to have a more precise way of knowing the state of my battery, especially that I knew I would be moving to solar eventually.

Adding a DC battery meter is quite simple in that it hooks directly onto any DC circuit you may have close by.

I went online and found a nice meter on Ebay for not much money. While I was at it, I realized I also wanted to know how much AC voltage I was getting while hooked to shore power, as well as the load in amps, so I found a similar meter on Ebay as well.

An AC voltage and amp meter is not only a good idea but is also a necessary one if you want to protect from low voltages that can sometimes be found in some campgrounds or parks where either the infrastructures are sub-par or have too many people hooked up at the same time. While a lower voltage may be fine for your coffee machine, it may not agree as much with your beloved AC unit, which is risking internal damages should the supplied voltage be under 103-105 volts.

Installing such a meter would then allow me to turn off the AC in such situations, or at least know what risks I was exposing myself to should I decide to keep it on.

I did not necessarily want to put the panel in the same area as the above control panel, and wanted my setup to be closer to the AC/DC distribution panel, which happens to be at the back of my trailer.

I used some plywood to build a frame where I could insert the three meters I ended buying, as I decided, late in the project, to include an amp meter for the DC side as well, allowing me to know the draw on the battery side of my system.

Early in the project, I realized that I may not need these meters on at all time, especially that they can be quite bright in a dark setting, so I added a switch for everyone of them, allowing to turn each of them on or off as I needed.

As you can see in the picture, the left hand side meter for a reading of my battery voltage, indicating a 13.46v that suggests that the converter is keeping the battery properly charged up. The middle meter was the DC amp draw, which was at zero at that time, and the right hand meter was the AC one, showing the voltage at the top and the draw (in amps) at the bottom.

Seeing how many amps you are pulling in can be a handy reminder to turn off the AC electric water heater before using the AC and vice-versa.