The replacement banner battery tested 5A load for 5.5 hours not a problem. So 2 would be 11 hrs to be tested Scotland 500 trip in May. Fitted a second battery today ready for a small inverter.
It would seem I have wired the battery incorrectly. I need to charge across the corners of the battery as well as take an inverter feed across the corners.
As there will be a small volt drop on the 170A cables that join the battery together. Added 170A cables to a 60A fuse and a 600W inverter pure sine. Then onto an auto switch so 6 sockets switch from main power to inverter power but only 2.5A at 240V. See blog about inverter.
Useful info from Caravan Chronicles website