Efficiency formula
Efficiency (%) = (energy out ÷ energy in) × 100. Charging 1,000 Wh and getting 950 Wh back is 95% efficiency.
What affects efficiency
Heat, BMS losses, and Peukert effect reduce real-world efficiency. Lithium is often 95%+; lead-acid can be 80–85%.
Frequently asked questions
Q: Can efficiency exceed 100%? A: No—output cannot exceed input in a passive battery system.