The Electronics 

As I do with every project, research comes first. I spent a long time researching different methods of energy storage (ie: different types of batteries) and decided on using SLA (sealed-lead-acid) due to their large energy density and high-rated safety factor.

I knew that I wanted the whole system inside of a cooler because a) I had already done so with the Bass Booster and b) it was an excellent way of housing a project for easy access to repair and high portability.

As for researching the electronics, I spent a lot of time browsing the internet and trawling through ideas that were too expensive for me. Keep in mind that I was 15 and unemployed, so I wanted to keep things as cheap as possible. For me, that meant finding a middle ground between cheap but sketchy, and expensive but reliable. Eventually, I settled on a mix between eBay.com and Amazon.com, buying the less crucial parts like the Arduino from eBay (slightly sketchy and very cheap) while purchasing the most important things like the SLA battery from Amazon.

I ordered all the parts and everything arrived within a few weeks time. I was now slightly more experienced with soldering and created a wiring diagram for all of my components and verified it numerous times to make sure nothing would blow up on me.

Through a lot of hot glue and simple soldering, I connected everything together and decided on the name "Power Hog." I wrote its name on the white lid in black sharpie and drew a little cartoonish pig above it.