A 48-amp setting is 50% more power than a 32-amp setting at the same voltage (11.52 kW vs 7.68 kW at 240 V). Overnight, that can matter for a long commute or a large battery, and it may not matter at all if the car cannot draw 48 amps or if you only need 30–40 miles back each night. The 48-amp circuit also typically needs a 60-amp breaker, two adjacent spaces, and a harder load calculation.
Time scales with energy, not with folklore. If a depleted 60 kWh battery were charging at a constant 7.68 kW, the energy math is 60 / 7.68 ≈ 7.8 hours; at 11.52 kW it is about 5.2 hours. Real sessions are not constant — they taper, and they start from a partially full pack — so treat those hours as illustration only.
On the all-gas 1,800 ft² educational example, the optional-method load is about 71.0 A at 32 A charging and 77.4 A at 48 A. The step up is modest in that light house and much more painful once a range or heat strips are in the general load. Use the calculator and read the car’s onboard-charger rating before you pay for a 60-amp circuit.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.