SOS I have to "flip the switch" on my 48 volt Lifepo4 Off-Grid HELP! PLEASE!

Sep 20, 2021
Timmins Ontario Canada
I am SO sorry this is such a long question but I am about to "flip the switch" on my 48-volt lithium off-grid system, and I want to check that I am not doing something terribly wrong which will cause my early termination :).

I am very confused. Situation: I moved to off-grid cabin. There is an existing square D panel that is powered by a generator. There are two extension cords leading from the generator shed into the cabin (I can't find their entry point-maybe under the cabin). As long as I plug both extension cables into the generator, the panel and electricity in the cabin works. BUT...if I only plug in one of the cables, NOTHING works. The panel looks like it has two hots coming in the top (a black and red on the left and a black and a red on the right side of the panel). This seems wrong. Why would one cord produce no power? There do not seem to be any 240 plugs or loads. There were a couple of panels attached to an 'eliminator' and lead-acid. I removed them.

I have mounted my 48 volt PowMr. All-in-one 5k 120 volt only (with no parallelling allowed) on my cement board and underneath that I have a 16 cell LIFEPO4 16S Thundersky 260 amp hour battery (without BMS, but with 2 X 8s Cell Meters to monitor the cells until I can supply-chain a BMS).

I don't know how to get this AC-OUT to work my loads. Can I use the existing panel? Would this be the 'main' panel and I'd have to get another panel? I saw the youtube showing attaching a 1500 watt extension cord as my AC out. Of course, I want to use more than 1500 watts. So can I forget the breaker box for now and just hook up 3 x 1500 watt (one 12 gauge and two 14 gauge extension cord female ends) - which would offer 4500 watts directly beside the inverter, simply ignoring the existing panel?

What if I only attached ONE extension cord female end? Would 5000 watts try to go through it and burn something up?

The extension cord female end solution is obviously not ideal, but I don't know how to get AC power any other way, except getting another panel and wiring it (no idea how) and then making another AC-In from the generator (I was going to use a "shore" cable from my old RV that presumably would be 30 amps as there is a special plug on the generator (a 7800 or so) for an RV cord (and I've never had 50 amps). So I was going to cut off the end of the shore power cable and wire it directly to the AC-in of the PowMr. So far that seems okay to me.
BUT for the AC-OUT- instead of 3 extension cord ends or buying and wiring a brand new distribution panel, can I just somehow connect my AC-OUT from the PowMr directly to the existing square D panel (by taking out the two top red and black presumably 'hot' inputs and replace them with just ONE 120 input from the PowMr? But in this case, will NONE of the existing lights and outlets work (because none of anything works unless two 120 v cords are coming from the generator).?

I desperately need electricity to work today to work and stay warm. I am out of wood. No propane can be delivered because the road ends 1/4 mile up and I don't have a 4-wheel drive. I've been 'moving off-grid for 6 months and was homeless and cold in my RV until I found this cabin. I think I have everything I absolutely MUST have to get the electricity working with my lithium system and my 9 x 230w panels - it is just this last little bit I don't understand (I'm sure I don't understand much of anything but I've read and watched enough not to be scared to deal with the other parts of the system...

Oh! Actually, I am still not sure exactly what order to put components, OR what order to connect them so as to avoid an in-rush that will destroy my PowMr. Capacitors. The manual DOES NOT SAY. I asked the company-they say there are not any further technical hook-up manuals and wouldn't help because I got the all-in-one on

I had to attach my whole post because it is longer than 10,000 characters!


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Photon Vampire
May 1, 2021
I think this one is beyond a simple forum reply but if someone is willing to tackle it they are going to need lots of photos. I can see that you realize that you are trying something that requires a fair bit of knowledge or a good electrician.