I have and had a pair of T-125's on each TT. When I sold my TT last year they were 10 years old and going strong. Actually no difference as they acted the same way. So it was a no brainer to place two on our new to us TT. The key is never to go under 50% discharge and to add a charge wizard to the house charger convertor, keep water topped up. We are going to add solar in the next week and see how they do and may add two more. At the moment when dry camping, I charge them up with our Honda generator. We dry camp about 50% of our days of camping per year.