About batteries: Since 1996 doing my [seasonal] RV living,
I've been using 16 golf cart batteries: 12 on the back bumper and 4
on the front bumper. They have been adequate for my RV requirements.
BTW, beyond the normal stuff, my RV utilizes two networked servers,
two workstations, two satellite uplinks as well as three satellite
downlinks and my ham radios, all on a 24/7 basis. The inverter is a
Trace SW-4024. Then in 1998, I bought the ranch and it, now, uses 16
of the venerable L-16 batteries, purchased from a dealer who wished
to rotate his stock. The ranch also utilizes a matching Trace SW-4024.
(For commonality of parts.) BTW, I also have a pair of Trace 12 VDC / 2400 watt inverters in case the big Traces fail. (Yep, I'm stupid on occasion. I didn't ground the one at the ranch well enough and lightning took it out. Now it's [replacement is] grounded to the well and four widely separated ground rods.) I went with the backup inverters as 12 Volt DC because they can be more readily utilized elsewhere if needed. Early in 2004, I installed a Trace SW-4024 at my [commercial] radio station with 24 L-16s and both stations operate continuously with the system interfaced with the city power feed. If the city power fails, the Trace picks up the load so fast neither the [audio] CD players nor the computers glitch. On the air, you can't tell that the switch occurred. Unfortunately the rest of the building, which isn't on the Trace, goes dark. This was very disconcerting to one disc jockey in particular. Ha!
As to longevity, we pull a continuous 24 Amps and so far, during a power failure, the system has gone almost 10 hours without running down. (Thank Goodness!)
As to those BIG telephone [Central Office stationary] batteries, they are HUGE and only one cell. It takes three of them [wired in series] to equal the voltage of one L-16. One battery must weigh 200 pounds. They are clear on the sides. I missed out on 42 of them when I ran across a telephone serviceman who had just finished dumping all of the liquid out of them and loading them on his truck for disposal. The EPA poses no problem as long as you affirm you are going to put them into service. EPA only has restrictions when you dispose of the battery. So far no battery failures and things are humming.
Best regards to you and the Memsahib, Oh ..... HAPPY NEW YEAR! - The Army Aviator