VRLA battery temperature concerns other than just thermal runway. I. Practical considerations

In this paper the effects of temperature on valve-regulated lead-acid (VRLA) battery performance are quantified for the following areas: (1) the capacity-temperature relationship (dC/dT) for discharge rates of 0.17 to 8.0 hours and a temperature range of 30 to 140°F (-1 to 60°C); (2) empirical equations are derived to allow the calculation of dC/dT for most discharge rates; (3) the external surface temperature which best tracks the cell internal temperature during discharge was found to be the container wall surface, parallel to the plates; (4) tests in which the -3 mV/°C coefficient is applied to prevent thermal runaway are shown to cause negative plate self-discharge at temperatures as low as 37°C (99°F); (5) a container wall surface temperature was found to be within 2°C of the internal cell in lift: tests at 50°C (122°F); and (6) experimental results indicated that cell failure due to negative plate self-discharge at 25°C may not be detected in elevated ambient or life test temperatures