MisterSandals
Participation Medalist
Its not a theory. You "can" discharge your batteries the entire "rated" Ah all the way to 0V, but doing so pretty much destroys them. By discharging lead acid only 50% (to ~12V) gives a few hundred charge cycles.I am aware about the 50% discharge theory [altho I think it's just good marketing,
Its like saying you "can" jump out of an airplane without a parachute. Once.