Battery failure

Hi.
Does anyone know of a charger or alternator problem that might cause repeated leisure  battery failures.  We have had 3 (115ah) batteries fail on us in as many years on our 2013 Broadway FB. (The starter battery is the original one and is in perfect nic.)  At the moment we are limping back to the UK from Norway and luckily the sun is shining brightly and we can cope on solar power.  We have been without hookup since May apart from 2 days. With 24 hours of hookup the battery fizzes , warms up drawing 18amps to start with going down to 5 .  Charging at no more than 14.1V . When disconnected stays about 13V for an hour then drops to 10.8 or les. Shorted cell perhaps.  Any ideas?

Yes looks like one of your cell's has shorted, don't know why but do you leave it hooked up and charging when it's being stored?

It is never stored. We have been travelling since November 2016.  By the way the current battery (6months old) and its predecesor are Banner top of the range. We have an 80w solar panel.

Well maybe you are reaching the max amount of cycle's the battery is rated for in only a year because your constantly using it. It's just a guess.

Google 'Banner battery failure' and get lots of similar stories. Here's a thread off outandaboutlive forum..

http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Banner-Batteries-Knackered-After-6-Months/40167/