Caravan OnBoard Charger

Grammarian47

3 months ago I bought a new battery (110ah) and have had it charging via electric hookup at home when not out on site. Initially the voltmeter showed it to be charging at 13.5amps but recently this has dropped to just 12amps.

I have used the van for several trips and use a solar panel when not on hookup. This tends to show the charge at 12.5amps.

I am now unsure whether the onboard charger is working. Is there a way I can check this?