Batteries & Energy Storage
What is round-trip efficiency and why does it matter?
Reviewed by SolvSolar · Last reviewed:
Round-trip efficiency is the share of energy put into a battery that comes back out again. LFP systems achieve 90–95%; lead-acid manages only 75–85%. It matters because every lost percentage point must be replaced by a larger array or a bigger bank, so low efficiency quietly inflates both system cost and roof area.