Now, ive had this non vw van for a while and decided to look inside this fitted wooden box.. I found among other things 2X 135AH gel batteries

They were pretty flat, but following some cables i found that there is a mains hook up hidden under the van! And also found a 20Amp charger under the seat

plugged into the mains and they are taking a charge. They are quite big..
H= 32cm
W= 34cm
D= 18cm
So they wont fit in the battery trays. I guess my question is, are they better as a leisure battery than a lead acid? I am quite happy with my current set up (2X80AH sealed lead acid) But these Gel ones would give me 270AH... My chargers have a gel setting, so no problem there. Do they have a value 2nd hand? as they are many hundreds of pounds new.

Time is a drug. Too much of it kills you