^ We just need people to use the units correctly AND consistently.
The ARB can draw 5A and in an hour of typical use (where it runs 5 minute on and 15 minutes off) 5A x 15/60 = 1.25AH
cheers,
george.
My point is that whatever charger comes with a panel is more than likely not what it seems. There's a reason it's thrown in for essentially $0. A real MPPT charger has quite a bit of electronics, well beyond 'free'.
And yes, I've been to Shenzhen multiple times for products that we manufacture...
Cheap "MPPT" that came with the panel.... Well, if it's the typical cheap from China and came with the panel, then it's quite likely not an MPPT, regardless of what they quote. Most are PWM and they put an inductor in there to pretend it's MPPT.
So, I'd be looking carefully at that charge...
^ What brand/model MPPT controller do you have. I use a Victron unit and have my fridge on the load side. No issue, voltage drop is minimal (more drop in the wiring). I like it on the load side since the Victron shows how energy usage by the load and of course energy coming from the solar. Let's...
Put it on a real charger (wall plugged) and monitor the voltage across the battery as it charges fully. Then load test the battery. Though it does sound like a dropped cell.
cheers,
george.