A modest proposal.
I have four different lead-acid starting batteries that hard experience had shown me with winter-time idle down time I need to removed and top-up charge at least once every four weeks. Do not do this and is replaces at least one of these set-aside ignored, every, next use season.
The John Deere/Yammar three cylinder diesel tractor has had it group 30H go time/age bad last year. NLA on group 30's anymore. I replaced with a slightly larger Group 31. A post version versus the more common stud terminal type's.
Measuring up it will be easy for me on the Miller/Kohler welder-generator to replace out the small Group 28 for a Group 31P.
Group 31P will fit easily in any one of the three Ford pickups. Group 31P can be squeezed into the Hyundai versus it's rare group 121R. Easy to fit a Group 31P into the wife's current Ford Edge replacing it's group 58 come the time. Group 31P can even be grafted into the Club Cadet riding lawn mower when it's becoming 3 year old U1 fails.
My needs are Grid-backup, Grid's Failed Us (four timed now since late Nov.)
2,3,4 of these Group 31's in parallel put my two 500 watt, two 1600 watt Rediline motor-generators into play.
Puts my Trace 2512 big'ol herky inverter into play.
Group 31's are available from low capacity/amps cheap, to high maps flooded plates, to high-amps vibration resistant AGM's, to pure lead stationary storage types.
THE most common, over-the-road diesel truck battery group size are 31's. Lots of backup there.
A practical, today use, suggestion.
J-I-C Steve Unruh