replacing UB4D battery with smaller one
I have a five year old Ford e-350 sportsmobile. I removed the fridge (now use ice box on back rack) and microwave oven to make additional storage space, and replaced all lights with LED's, and thus do not have much current demands. The very large house battery, the UB4D (114 pound, 20.75 L, 8.5 W 10 H) is now dead and not holding charge. I need to replace it, but it is both very large and very expensive and I do not think I need as much battery.
Here is my question for the forum.
1) Advice on what battery could fit securely in the battery carrier (under the van by the rear axel).
2) Advice on what brand and model which would still have good ratings, high amp hours, but not as much amp hours, etc. as the very large UB4D
Much thanks in advance.