As others have said, the capacity (Ah rating) is about how long the battery will last before needing recharging.
My Powrtouch MM has been used to move my (1310Kg single axle) van nearly 100yds plus the shunting out of one storage bay into another really rather snug one with lots of toing and froing to line up, and the depletion on my 100Ah battery was unmeasurable (state of charge was no different between before and after) with my battery state of charge/health meter (not just a voltmeter, but a analyser type device as used by industry to check battery condition).
Just looked at Powrtouch web site and for their twin axle 4 motor mover kit that will move 2.8 Tonnes up a 25% (1 in 4) slope, they still only recommend a 100Ah battery!
Think you are likely being fed BS, unless your particular brand of MMs are horribly inefficient and kill batteries on sight!
I've never depleted my battery to any measurable degree by use of the MM in 2 years of ownership. A 85Ah battery would still be fine if you only used EHU sites and maybe had a solar/trickle charger in storage, but 100Ah just gives you a bit more wiggle room for a less than fully charged battery, and the negligible difference between 100Ah and 110Ah claims is absolutely nothing to be getting worried about.
Don't think I'd contemplate the expense and aggravation of upgrading the locker to fit an over specified/oversize battery for no good reason! Be guided by what the MM manufacturer says in their sales blurb/handbook, rather than your fitter.
Message posted by Mrs. Bonce via mobile 16/10/2020 at 7:06pm Outfit: Shogun and Coachman VIP 575 Location: Luton (no jokes please)
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