Did you have a power outage and come in to the office to find that your crucial computer was dead to the world even though it was hooked to a UPS?When you buy an Uninterruptable Power Supply (UPS), make sure that when you install it, you write on the outside with a magic marker the date you installed it so that you can establish a routine for either changing it to a new one or changing the battery in it.
A typical UPS battery has a lifesoan of 3 to 5 years depending on its host operating conditions. On the other hand instead of replacing the battery, you may want to replace the whole unit on crucial systems because the metal oxide varistor in the surge protector wears out over time.