# Energy budget; usable fraction and load are assumed constants
voltage = 24 V in 12..48
capacity = 10 Ah in 2..20
usable = 0.8 "Assumed usable capacity fraction"
load = 60 W in 20..150
energy := voltage * capacity * usable [Wh]
runtime := energy / load [h]
check runtime requirement: runtime >= 2 h
scenario high load: load = 100 W