How To Build A Backup Battery System

A coffee maker or a toaster will surprise you in that they have very high power consumption demands. They will consume anything from 800 watts up to 1500 watts or more. What you need to do when you are setting up your system is look at the devices that you are going to be powering. Then get the inverter that will be large enough to power your needs and wants.

Inverter charge
This Motomaster inverter shows the amount of charge that the battery has. You can monitor it and be aware of when it is going to run out. This unit has two outlets and a USB outlet. It also has a port to use a remote control to turn it on and off.
inverter remote
A wired remote control came with this unit. Ideal if you have the unit in an RV’s storage compartment and want to be able to turn it on/off from the comfort of your easy chair.
Inverter draw
The display flips between the battery capacity and the amount of draw on the system. With nothing plugged in it will be zero – it will, however, eventually drain your battery so do not leave it on. Here the device plugged in is pulling 20 watts.
open tote
I used a spare courier envelope to stick to the lid of the tote, reminding anyone using the unit to leave the lid open when using/charging the system.
Compact electricity
This is a relatively compact system that will power a wide range of electrical devices for 24 or more hours. Need more – add a second battery. Needless, well, then there are many other options from using a smaller battery and inverter to getting something from your favorite shopping outlet.

This is our DIY electrical power. Pick up the bin (carefully, it’s heavy) and put it in your trailer, pickup truck, van, or car and you can haul electricity along with you. If you have an RV, then adding an inverter to your existing battery array will provide you with AC power in addition to DC power. Will everyone want a system like this – probably not. Can you purchase an inexpensive generator for about the same amount? Yes. There are times that a system like this will be exactly what you want. Next, we need to get a solar panel so that we are truly off the grid.


Products Featured:

MotoMaster Eliminator



  1. Why didn’t you use a lithium ion Car battery for a light weight solution?
    Why not put everything on a movers dolly so you can wheel it around easier?

  2. Why not use an lithium ion car battery instead of the heavy deep cycle battery?
    Couldn’t you put the bin on top of a movers dolly to more easier roll the thing around instead of trying to carry it?

  3. Hi Davin x2,
    Great questions. The idea behind a deep cell battery is that it can handle the repeated draining and charging required in a setting like this. A Group 27 lithium ion battery, similar in capacity to the Group 27 battery used here, would cut the weight in half as they are just under 30 pounds. However, they cost in the neighbourhood of $1000 which is FIVE times the price of the battery used. Our choice was the best price to power ratio.

    A car battery is designed to provide a huge burst of power for a short time and then be recharged by the alternator. Drain it frequently and it’s life will be shortened. A deep cell battery is designed to provide steady current over a long period of time; drained right down without shortening their lifespan. It will not work well to start your engine as it doesn’t have the cranking power.

    The Group 27 is a large and obviously heavy battery and was specifically chosen for the lifespan and amount of ongoing power it would provide at the expense of weight. We knew it wouldn’t be portable. As mentioned in the article on page 3, we will be getting some castors for the case so that it can be rolled about more efficiently.

  4. Hi there,

    You mentioned solar panels. How would one go about hooking this up to solar? My son had SMA and we’d like to take him places next summer. This with solar would be perfect.

  5. Hi Mike, I don’t know a lot about solar power but it appears to me that many solar panels have the ability to charge batteries. I will be looking into this more eventually. Sorry I cannot give you more substantial answers but I just haven’t set this up myself.

  6. Quick crazy Question..
    could i adapt this as a in car solution to not use the existing car battery? how would i charge? i guess plug in the charger to either an alternator or in to a lighter socket? Is this possible?

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