This timeless expression applies to so many situations, situations — ever rushed. Ever rushed to the doctor’s office just to wait forever before they call you back? Most batteries live their entire life in this perpetual purgatory just waiting for their moment to shine. Usually they are in a flashlight, remote control, or garage door opener, but batteries also backup mission critical systems, telecom equipment, and other critical appliances we need when the grid goes down. Too often, though, many of these batteries don’t work when they are needed the most. These batteries fail, and there are many reasons why. Most importantly, there are a few things we can do to prevent these failures and make sure the lights stay on.
Batteries provide power to utility control systems, industrial plants, and critical communications systems when the power fails. Traditionally, lead-acid batteries have been used for backup. The two most common lead-acid chemistries are flooded lead-acid (FLA) and valve-regulated lead-acid (VRLA). These are both simple combinations of sulfuric acid and lead plates in plastic containers. During the charge process, the positive plates change to lead peroxide, and the negative plates turn to pure lead. During the discharge process, the acidity of the electrolyte solution increases, and the specific gravity of the solution decreases. Both lead plates now begin to change to lead sulfate. That continues until there is no potential difference between the plates, though this should be avoided.