Rebuilt my Mobile Knife Sharpener's Solar Power Storage Box

For those of you who are paying attention, I have had to change my solar power system's storage box.  My first storage system used a tool box or cart made by Stanley. Below is a picture of it in use:

Solar Storage System Using Stanley Tool Box

I really liked this Stanley tool box. The bottom compartment held the AGM battery, I had a shelf built to hold the power inverter just above the battery, and the top box held extension cords and other tools and parts related to storing and distributing the DC and AC juice.

The other nice aspect of the Stanley tool box was the flush mounted wheels, and the folding handle. 

Since my business is mobile — mobile knife sharpening — I need everything that I use to work in this mobile environment. I drive to where I will set up, pull everything out of my truck and set up my sharpening booth.

The Stanley tool box, with the wheels made it easier to set up. The AGM battery that I use is made of lead, and lead is heavy. The wheels on the  tool box made it a lot easier. The wheels being flush mounted (and the folding handle) made it a lot easier to pack away.

The tool box — unfortunately — was not robust enough to hold up to day to day business, especially with an obscenely heavy 56amp hour lead acid AGM battery. In the photo above I can see the half circle of air where the right wheel of the box used to be. The wheels were the first to fail. The metal axle was held in place with plastic tabs, and they let loose after some time. Once that happened I started to drag the tool box around. Dragging the tool box on asphalt did not help matters!

My Poor Battery Storage Cart Abandoned in a Recycling Cart

My Stanley Tool cart spent its life helping me sharpen knives by holding the battery and the power inverter that I needed for my solar power system. This is how I reward my loyal tool — abandoned in a recycling bin. So sad...

Plywood Battery Storage Box

I could not find an off the shelf tool box that seemed to fit my needs, so I decided to go the custom built route. 

The picture above shows the beginning of the box. Visible in the bottom are the cleats that will hold the battery secure. After this picture was taken the wood was sealed, and a couple of wood pieces that are placed above the battery were cut.

Solar Battery and Power Inverter Storage Box

Here is a picture of the completed box. This view shows the entire box, the power inverter, and the Anderson connectors that runs to the solar panels.

The AGM battery is visible at the bottom, the power inverter is the large black chassis mounted up on top, the power inverter sits on the rails that hold the battery down. The box is as open as it can be so that all the parts and pieces can be easily accessed for inspection and maintenance.

Solar Powered Knife Sharpening

Here is a picture of the whole setup. The box is in back, the folding solar panels are in front. The box — with the heavy lead acid battery and other gear — makes a great anchor for my popup canopy. In this picture you can see a bungie cord running from the metal handle of the box up to the popup.

Everybody asks if the this solar setup can operate my knife sharpening system. I say 'yes.' I explain 'duty cycle,' in that the machines are off when I am awaiting customers, and also mostly off when I am actually doing knife sharpening. Other that the actual sharpening when the machine is running — other work steps include inspecting the knife, adjusting the machine, cleaning the knife, wrapping the knife and such. All of these steps are done with the machine off, and during all this time the solar system is charging the battery.

With most any sunny summer day the battery sits full, and the charge controller has the voltage to the battery turned off.