Help with diy vortech battery back up

[gar732]

Ok with impending storm my power is almost sure to go out, so I'm throwing together a diy battery back up for my vortech. I got all the stuff I need I just have a questions as to how it's wired. As you can see from the pics you can change the polarity of the dc plug depending on which way its plugged in. Can anyone tell me which way I should have it?

 

[skinz78]

Hmm, not sure if you figured it out yet but I'll see if I can't answer your question here. It is pretty easy to determine the negative or neutral wire in most cases, the negative wire should have a ridge or a series of ridges on it and the positive wire should be smooth. I hope this helps and if you need further info on how to on one of these check out this thread: https://www.reef2reef.com/forums/do-yourself-diy/59473-battery-back-up-your-vortech.html

 

[skinz78]

also if you don't have a line on the negative wire you'll need to get an electrical tester that you can test continuity with, touch one lead to the outside of the big round part on the plug in your first pic, then figure out which of the two smaller prongs it is connected to, that will be your negative prong.