Are you managing the expected lifespan of UPS batteries, or do you not have to worry about their lifespan just because the devices are under warranty? UPS is like an unreliable friend – you may think you can trust them, but they may disappoint you when you least expect them or even need them the most. The backup power system in data centers may have several drawbacks: damaged circuit breakers, poor power management or phase balance that can lead to overload, and even design and safety issues. Even if everything else is correct, the uninterruptible power supply (UPS) battery may still be a weak link.
Before the problem occurred, the battery seemed to be functioning normally. When a malfunction occurs and suddenly switches to relying on UPS battery power, the load becomes heavy. This will put a lot of pressure on the batteries and may lead to their failure, as well as potentially devastating consequences for data centers.
UPS battery options
The UPS battery options have not changed much in recent decades: either wet lead-acid batteries or sealed lead-acid batteries (VRLA). Wet batteries are still standard equipment in large data centers due to their long reliability. These types of batteries are immersed in large and expensive sulfuric acid tanks, requiring regular monitoring and maintenance, as well as sealing measures to strengthen safety precautions and separate rooms that may contain sulfuric acid from UPS.
VRLA is currently the UPS standard for data centers. These batteries are sealed in containers with a paste like electrolyte and also use a different charging system, making them safer and avoiding special facilities that hold them. VRLA requires longer charging time than wet batteries, and another reason is the lifespan of UPS batteries. Wet lead-acid batteries can have an expected lifespan of up to 25 years with proper maintenance, while VRLA batteries need to be replaced after 3 to 5 years.
Extend UPS battery life
Data center managers must take measures to maximize UPS battery life and prevent catastrophic failures.
Each UPS should be equipped with at least two sets of battery strings. If one of the groups fails, the second group should be able to maintain power – although this duration may be reduced to less than half of before. The lifespan of UPS batteries is a nonlinear function. Two sets of battery strings will have a lifespan more than twice that of a single set. At least you won’t encounter sudden accidents.
All UPS systems require two sets of battery strings to prevent catastrophic failures in the event of one set malfunctioning.
VRLA batteries typically cause overall failure: a single fault can lead to the failure of the entire battery string, with no indication of which specific battery is at fault. Wet battery failure or short circuit can cause a decrease in the total voltage of the battery string, but UPS can still continue to transmit electrical energy.