To assess the cycling efficiency of the Li electrode in a positive‐limited secondary battery, Li has been plated and stripped from a Li substrate. This has been carried out in a specially designed cell containing a Li electrode of known volume: Li is plated and stripped from this electrode until the substrate is depleted. Individual efficiencies can also be determined from inflections in the stripping curves. Average efficiencies were best for PC, which had been preelectrolyzed and treated with activated neutral alumina. Here, for 10 C/cm2 cycles about 85% cycling efficiency was obtained, essentially without change until the substrate was depleted. In general, showed inferior behavior to .