Lithium Batteries replacing VRLA for UPS applications

Yigal Schneider - May 22, 2017

Lithium batteries are replacing VRLA batteries in Static UPS applications. I predict that in 5 years, almost all critical facilities such as datacenters will switch to Lithium batteries. Here is why;

UPS applications traditionally use Valve Regulated Lead Acid (VRLA) batteries to provide back up power when the power goes down. VRLA batteries are a known and tested technology. It is relatively low cost (initially) and allows flexibility in specifying the autonomy time (discharge run time).

However, VRLA batteries have significant drawbacks.

  1. Due to Lead acid chemistry’s low energy density, VRLA batteries consume a lot of space which is very expensive in critical facilities. They weigh a lot too.
  2. VRLA batteries decay very quickly. Critical facilities replace their batteries every 6-7 years so the total cost of ownership due to replacement costs is quite expensive.
  3. VRLA batteries require regular maintenance or, better yet, a good battery monitoring system. That costs money too.
  4. VRLA batteries’ life is very sensitive to temperature. So, you need to cool them down through-out their life. That costs a lot too.
  5. For safety reasons, VRLA battery rooms need to be ventilated by a separate ventilation system. That costs money to build and operate.


How do lithium battery fare in comparison?

Lithium batteries consume, on average, 70% less space (and weight) than VRLA batteries and free up a lot of expensive datacenter space to IT systems.

Lithium batteries need replacement every 12-14 years, they have a built in monitoring system, require no ventilation and are far less sensitive to ambient temperatures.

With Lithium batteries in UPS applications, datacenters are more resilient and their total Cost of Ownership (TCO) is way more attractive. That is why, I believe the days of VRLA batteries in critical facilities are numbered.