I took a look at the DC/DC converter last night.
It appears to be some sort of electronics power supply that can run directly from either DC or AC power, and provide up to 180 watts.
I rigged it to run from 115 volts AC from the wall with a cord. I tested the output from it, and sure enough, I get 12+ Volts. I tested it with a 12V bulb and a couple other small items.
Next, I played with the adjustment potentiometer on it. I was excited to see that it has a wide range of output. At the highest, it put out 14.25VDC. At the lowest, it output 9.25VDC
I should be able to use this in the truck, running off the main battery pack to output 14.1V (or whatever charging voltage I want) to the 12V truck battery. The only downside is that it's obviously NOT weatherproof. I'll have to make sure it is properly protected from the elements, but still gets plenty of cooling. It doesn't have a fan on it either. I could add a small 12V DC fan real easy. It didn't get hot at all in use, but I wasn't loading it down to hard or for too long either.
I ran it through a Kill-a-Watt energy meter on the AC side. By knowing how much energy was going in, and the wattage of the loads I was connecting, I can calculate the efficiency. Looks like the power supply is over 90% efficient. (I was just doing quick math in my head. Hard to hold electrical contacts and write down numbers at the same time.)
At the same time, I also dug out a box of misc. winter EV-related parts. In there, I found that I had a battery heater blanket that's pretty big. I think it's designed to wrap around 6 Group 24 batteries at once. Thats about 150 watts of heat.
I also found that I had a 30 foot, 60 watt, electric pipe-warmer tape. That's a material that you wrap around pipes to prevent them from freezing and bursting. It runs on AC power and has a built-in bi-metal switch. When temperatures are low, it turns itself on. When things are warm enough, it turns itself off.
I thought the pipe-wrap might work well for heating the fuel tank on the truck. Diesel is never especially warm, but if I ever want to use veggie oil, I know that has to be nice and warm to run. I know I'll need additional heating for a veggie tank, but the pipe wrap might work well for the diesel/bio-diesel tank.
Another fun item I realized I had was a 1-ohm resistor. Recently, I read on another thread on Ecomodder of somebody using a one-ohm resistor for something or another and mentioning how nice the math works out on it. I can never remember all those electrical laws, so I just looked it up on a calculator. Sure enough, at 12V, one ohm draws 12amps. And 12V x 12Amps is 144 watts. That's pretty hot for a 6-inch cylinder.
It may actually be enough power for a decent, basic electric defroster. I think if I had it mounted on a bracket with a small DC fan, pointed towards the windshield, and a 15-amp fuse, it might work well. Look a little funny, but work well.
