EG4 F80 Fault Code fixed


Just passing through this old world.
Oct 12, 2022
So I want to start by saying I'm a noob and am only posting this because after searching for a fix and not finding it, I believe I resolved it and want it out there for others to discover. For you veterans, yea I know this will be obvious to you. This is my first solar setup so don't roast me too bad.

So I have 2 EG4 6500ex inverters 180* phased with 3 eg4 Lifepower4 batteries and 12 460 watt panels ground mounted about 135 feet from the inverters. This setup is just meant as a backup generator and isn't connected to the grid at all. My intention was to be able to plug my 50A extention cord into where my gas generator was connected and use the solar in the event I cannot get gas or the generator is down for service.

After installing everything and starting it up, everything worked pretty well. It was later in the day and the panels were outputting about 1kw each string. There are 2 strings on this array and I had both going into 2p1. I figured I would leave 2p2 pv inputs open for a later array I have planned. So the setup worked for the times I turned it on and on battery alone, I was able to pump 10KW into the house no problem. I wanted to test them charging and on a load so I turned on my heat pump and lights. When I was next to the inverters after they had been running for 3 hours or so, the fan started to go much faster, then slow, then fast again untin 2p2 faulted F80 and eventually shutdown. It did this again after restarting. It even did it after disconnecting all my loads as long as the inverters were on. I tried several things including twisting the phasing cables and even putting ferrite cores around each leg to help with noise. I also updated all the firmware on the inverters and the batteries. ( This was a good idea anyway ) Nothing fixed it.

I clamped my DC meter on the 4/0 cable to the battery and noticed at 61 amps is when it faulted. I knew the batteries could charge at 120Amps potentially and the light bulb went on in my head. Looking in the instruction on the very last page in the section and the very last line in this itsy bitsy book, it said each inverter needed a seperate PV module. Yea, weird way to word it but I proceeded to take one of my PV inputs from 2p1 and put it on 2p2. Now when I powered it up, the clamp on meter went to 60Amps then to 0, but then went to 65 amps and climbed to 80Amps and held without fault. My panels were bringing in 2.28kw per string from 135 feet away and charging the batteries. I decided to put a load on the inversters so I started my 2 ton heat pump (soft started) and my 600 watt shop lights. The inverters worked great and the only thing I noticed was the battery amps dropped to 35A charging. Makes since because of the load and no more solar to supply the added load.

So all seems fine now. I'm going to fully charge the batteries and try loading the system at high noon and see if it faults, if not it's golden.
I'll report back what I find.

Hope this helps someone out there.