Estimate mobility scooter range.
Scooter range is runtime multiplied by speed, and runtime is usable energy divided by the average load. Usable energy is amp-hours times voltage with a 20% deduction, because taking a sealed lead-acid battery below about 80% depth of discharge shortens its life sharply. The load side is where manufacturer range claims diverge from reality: quoted figures assume a light rider on flat pavement at steady speed, while gentle slopes raise the average draw by around 25% and hilly ground by 60%. Rider weight adds a smaller but real penalty. Batteries also lose capacity with age, so a two-year-old scooter should be planned at perhaps 70% of this figure.
Mobility Scooter Range
Usable Wh = Ah x V x 0.8; load = motor watts x terrain factor x weight factor; runtime = usable Wh / load; range = runtime x cruise speed
Quoted ranges assume flat ground, a light rider, steady speed and a new battery. Slopes, stop-start use, cold weather and battery age each take a share, and together they commonly halve the figure.
Sealed lead-acid packs typically last 12-24 months of daily use. If your usable range has dropped by a third from new, the batteries are near the end regardless of age.