When I bought Tortuga it had what appeared to be the original batteries. They were monsters and I very nearly fell off the ladder carrying the 90lb Surette (far right in the photo).
After failed attempts to resurrect the old batteries I replaced them with three used Group 27s for the house bank and an isolated automotive starter battery. The house bank are showing their age. With the fridge on overnight they draw down to 12v by early morning. Time for new batteries.