I put it together today. Added a nice isolator switch (thanks Gunner). So now the UPS can be fed with 12 volts either from a battery, or from the truck. I have tested it. The internal battery seems to be in poor condition, which now explains why they threw the UPS away. But I do not care much as I can get 12VDC from external sources. I bought too few cable lugs and therefore could not properly connect it to a running engine. I connected it to a deep cycle battery lying in my garage. Then I powered up the UPS without being connected to the power grid. It started up and gave current on its outlets.
Tomorrow or soon I will buy two more cable lugs, will make nice disconnects for the pickup, and will try to put some sort of a load on it, maybe my space heater or my 500 watt worklight something or that sort.
It was not without trouble. When it was powered by AC and I connected the cables to the deep cycle battery, something blew inside the UPS. I suspect that what blew was some electronic piece responsible for battery charging. So now the UPS does not charge its battery. I do not care much about it however, as I can always use a trickle charger. Everything else works.
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