I mostly worked on building more fast fences today. I realized it would be better to upgrade my previous prototypes to the final version because there are a lot of parts that didn’t change, but that means taking apart the prototypes.
In other news, I looked into making a battery pack to run AC tools. There are commercial versions of these that are lithium-ion batteries in a box with an inverter that work like a little genset. But they are pricey. I want to run AC power tools, that usually run on universal motors. So I shouldn’t need an inverter, I can run directly from the battery at say 80 volts DC instead of 120 AC. It all sounds good, but I can’t find much info about doing it and the batteries are still kind of expensive. If I do it, it will probably use 12 volt LiFePO4 batteries that have a built-in BMS to prevent damage, then use 7 in series to get 100-80 volts DC.
The impetus here is I had an inherited scythe for cutting hay and brush but the blade broke, and the replacement was 110 CAD! That seems like a lot compared to a carbide brush-cutting disk for 20 CAD. I want to be able to use a corded electric brush cutter wherever. I could just buy a cordless version but the batteries are still expensive and you’re locked into one brand for those batteries. With a DC battery pack of my design I could run a brush saw, chain saw, lawn mower, other home-built equipment, etc that’s designed for AC power anywhere.
The gas versions of all these are something I’m trying to avoid because:
a) I don’t know much about working on small engines
b) I don’t want to pay for gas
c) I don’t want to spend time on maintenance, electric is much simpler mechanically
Sun Aquasystems 