Question 1

Why does my battery last shorter than the calculated runtime?

Accepted Answer

Several factors reduce actual runtime: aging (reduced capacity), temperature effects (capacity drops in cold), inverter losses if using AC devices, Peukert effect at high discharge rates, and the cutoff voltage limit which prevents using the last 10-20% of charge for battery health.

Question 2

Does voltage affect runtime?

Accepted Answer

Higher voltage batteries can deliver the same power at lower current (P=V×I), which reduces I²R losses and the Peukert effect. This is why 48V systems are more efficient than 12V systems for the same load — less current means less wasted energy as heat.