Battery display confusion

[MisterB]

I have noticed the battery reading on our motorhome dropping consistently over the last few days at Hereford. This morning it was showing 50%, below which I understand, can impact on life of the batteries, we have 2 X 130A batteries- we were planning to visit Ross on Wye, so nipped out for the morning. It's only about 20 mins or so from Hereford, but when we got there the battery display was showing 83% and when we got back it is now showing 100% - yet we only drive for about 45 mins maximum.
We don't have a B2B so I doubt the charger would replenish 50% of 260A that fast! Which leads me to think it's a faulty display.

Can anyone recommend any simple checks please to try to get a true/accurate reading of available battery capacity, base vehicle is Fiat Ducati 2018 130BHP and Adria manufacturer.

Thanks in anticipation

 

[Tombola]

Did you view the reading as soon as you stopped, as you'd want to let them settle to get a true reading.
You can always stick your meter across the terminals to check if they equate too after settling

 

[MisterB]

Did you view the reading as soon as you stopped, as you'd want to let them settle to get a true reading.
You can always stick your meter across the terminals to check if they equate too after settling

Yes, I read it when we had driven to Ross and then again before we set off to come back. Same reading both times. Similar as when we got back, 100% when we arrived, then 98% half an hour later ...

 

[nabsim]

If capacity has been lost they will also do as you explain above, also I think if a cell has gone in one of the battery’s. Only way I know of testing capacity is fully charge then put a known load on and see how many hours it takes run down. Do each battery individually.
I believe you can get a tester that does this for you now but don’t know where or what they are called, certain,y not a drop tester as used for car battery although that would tell you if you had a dead cell in one of them