We have 2 Varta LDF 90’s. one habitation and one for the engine, both 2 1/2 years old.they have a 5yr warranty. I bought them on advice from (think he is called Alan) at Atlantic MH.
I prefer to be off grid , so I fitted an 80W solar panel in 2012, and that seems to be sufficient in the summer; but we are not big energy users, no TV .microwaves etc. and try to charge phones and laptops when the sun is up. or when we’re on the move.
I always hookup for a day before we go and as soon as we get back to keep the battery in good health.
These are the 3rd pair of batteries the van has had from new , so they do seem to last about 5 yrs on average.
The longest stay without driving or hookup is 2 weeks at the TT and it managed fine. but that’s max daylight hours and minimum drain and maybe 3l of LPG.