Patent ID: 8340934

Claim:
A method of conducting performance analysis of a valve-regulated lead-acid (VRLA) battery in a battery set of two or more VRLA batteries, comprising the steps of: consecutively gathering float charge voltage variables of the VRLA battery through a measurement device, and conducting cluster and weighted analysis and obtaining results of the battery performance through a computer; wherein the mentioned float charge voltage variables are any one or the combination of those selected from the group consisting of: float charge voltage variables of a single battery relative to itself, a float charge voltage variable of a single battery relative to the battery set, variable of the float charge voltage dispersion ratio of a single battery relative to itself and variable of the float charge voltage dispersion ratio of a single battery relative to the battery set; wherein the float charge voltage variable of a single battery relative to itself is obtained through following steps: storing float charge voltage of each battery in a certain period; and calculating change of the float charge voltage of each battery relative to itself in this period; and wherein the float charge voltage variable of a single battery relative to itself is calculated by equation (1): μ i = 1 n ⁢ ∑ j = 0 n ⁢ U ij , Δ ⁢ ⁢ U ij =  U ij - μ i  ( 1 ) where: U ij : the voltage of the battery i at the moment j; μ i : average float charge voltage of the battery i in sample period n; n: sample period; and ΔU ij : float charge voltage variable of a single battery relative to itself.