enter battery capacity and charger power，by SoC range、charging efficiency and trickle curve，estimate theoretical / actual replenishment time。applicable to EVs and low-voltage storage systems。
formula：energy to replenish = capacity × (targetSoC−startingSoC)/100；grid power draw = energy to replenish ÷ efficiency；
theoretical duration = grid power draw ÷ power；actual duration ≈ theoretical × 1.15（trickle charging slows as charge level rises）。