Update: after working out what we ‘need’ and taking into account what we ‘want’ my current solution is as follows. I bought an eco-worthy 280ah lifepo4 battery and a 20a mains powered lifepo4 charger, total was £475 delivered, this is in the rear near side cupboard, it fits diagonally on the floor, almost perfect fit. I’ve replaced the 12v isolator switch in the cupboard next to it, this is now a 1, 2, 1+2, off switch, this leaves the original GC wiring intact, no mods other than the switch change. The battery was fully charged before we went off on our 4 night off grid adventure over the bank holiday weekend. I don’t have solar, so, this was purely on battery, the the eco worthy battery that is, so not using the AGM has battery at all.
We ran everything we ‘needed’ and everything we ‘wanted’’. Fridge was on all the time, heating overnight when it dropped cool, TV, lighting, awning light etc, charged all our devices of which there are a few, exactly as if we were on hook up. The hot water / heating was done on gas of course but the fans are 12v.
So, conclusion is, we used 30% of our battery capacity which I can see on the batteries Bluetooth app, it was at 70% (soc) when I switched back to the AGM before we left. So, let’s say around 95ah in total.
I’m now happy that we could comfortably have enough 12v off grid power for over a week. Happy days. Oh, I simply ignore the GC onboard battery gauge, which shows 100% charged all of the time, simply look at the app on the phone to check the eco worthy battery level.
I have to say also that the app, albeit a little basic, is very good, and the battery BMS is excellent, perfectly balanced cells we were achieved using the mains charger.
I use an ECOFLOW for the 240v, this is wired in to the GC mains via a Wago connection to the original input via a machine rotary switch, this has 1 output (to the input side of the ac fuse panel) and 2 inputs, 1 from the external mains socket and one from the ac output on the ECOFLOW, as it a fully connected / disconnected rotary machine switch, the pins on the input socket(external) are never live.
I simply unplug the mains charger under the passenger seat so as not to charge the AGM battery.
The ECOFLOW lives in the front of the utility cupboard next to the rear cupboard on the left hand side, again, it just fits (ECOFLOW delta 2), this give us around 45-60 minutes of mains power to run any high power mains items (air fryer) for example. This is enough for us, a few air fryer sessions over the weekend were done and 40% (soc) on the ECOFLOW at the end of the weekend.
This is purely for information on my experiences and requirements. I understand people may need more AC power and inverters and such-like can be used to accommodate this, but for us, it’s more than enough whilst not plugged in to the mains.
I’ve concluded from this that a 150ah battery would have been enough, however, there’s no doubt that a week or more 12v power would be available from the eco worthy battery and at the price it’s really good value.
Hope this is helpful,
