Maintaining `maintenance-free´ batteries

The maintenance of valve-regulated sealed lead-acid stationary batteries is described, and comparisons are made with traditional vented lead-acid battery maintenance practices. The operation of the valve-regulated sealed lead-acid battery is also discussed. Two designs are currently available, both of which operate on the oxygen recombinant cycle. This cycle effectively eliminates evolution of free hydrogen gas under normal operating conditions. Maintenance considerations for valve-regulated sealed lead-acid cells are similar to those for flooded cells. It is noted that the terms `sealed´ and `maintenance-free´ commonly associated with these cells are misnomers, and it is urged that the use of such terms should be discontinued