Know Your UPS Batteries III: Lithium Ion Batteries
The third battery on our “get to know you” list is the Lithium Ion battery (LIB). Lithium Ion batteries have seen significant growth and adoption in the last few years. They provide high-density power/energy for a number of devices, including the automotive, electronics and telecommunications field.
A Lithium Ion UPS battery is a dry cell battery, versus a Wet Cell battery-which requires periodically replenishing the electrolyte liquid. Lithium Ion batteries can typically see significantly higher number of discharge cycles than their VRLA counterpart.
The Lithium Ion battery (LIB) has three primary advantages when compared to others. They are:
- Long Life – Lithium Ion batteries have a life cycle 80 times greater than VRLA batteries, according to the Power Electronics Division at Toshiba International Corp.
- Lighter – Toshiba states that Lithium Ion batteries weigh 40 to 60% less than a VRLA battery solution, and can be up to 70% less weight than Wet Cell batteries.
- More Compact Footprint – These batteries take up less space overall in a typical UPS battery arrangement.
The operating environmental temperature requirements for LIBs are highly based on the specific chemistry of the LIB. These batteries do well in environments up to 95 degrees Fahrenheit. Toshiba’s Lithium Titanate battery can be housed (stored) in an environment with an ambient temperature up to 122 degrees Fahrenheit. This battery also comes with a 12-year, full warranty.
Lithium Ion batteries are unique in that they can be monitored at the cell level. In most UPS battery configurations, monitoring is available as an option for individual batteries, or the entire battery string(s), and can provide information about temperature and performance. In a Lithium Ion battery set-up, a monitoring management system looks at historical data at the cell level. Monitoring each cell can help with early warnings for potential hazards, such as thermal runway. Lithium batteries are not still vulnerable to thermal runway, but that is the main reason all lithium ion batteries are required to measure their individual cell temperature. The monitoring has the ability to turn the cell/power module off once the internal temp reaches a certain set point, depending on chemistry and can help avoid or eliminate overcharging or overheating.
Maintenance on Lithium Ion UPS batteries is fairly non-intrusive. This type of UPS monitoring typically involves a visual inspection and testing of battery connections by a trained technician.
Though the frequency of UPS battery maintenance is chemistry-dependent (be it lithium titanate, lithium phosphate, lithium manganese, or another chemistry), maintenance schedules for LiOn batteries are often reduced. You can usually obtain a warranty from the factory, dependent on the battery chemistry. Each manufacturer may be different, in fact, Toshiba provides a 12 year warranty with their Lithium Titanate batteries, which is all inclusive and requires minimal maintenance-included with the warranty.
There are new ULs out currently to comply with Lithium Ion safety and precautions. Some of these ULs are:
- UL94, V0 for a flame retardant jar
- UL1778 for UPS applications
- UL1973 for light electric rail applications
- UL1642 reduce risk of fire or explosion
These ULs require monitoring at cell level to minimize fire hazards. If the ambient temperature around the battery is too high, this can cause dangerous fires and ruin equipment. Toshiba’s Lithium Titanate UPS Battery eliminates carbon in the anode, virtually eliminating the overall risk of fire.
Safety is KEY with the Lithium Ion battery technology. Some designs maximize their energy density, others their power density, and still others their safety.
The Data Center market is a new application for this technology and some have adopted the technology willingly, but some are still hesitant due to the fire risk and media coverage of that risk in prominent news stories.
There are many technical considerations that go into decision making about any UPS battery. The popularity of Lithium Ion batteries is growing in the UPS field; however, it is still important to weigh the advantages of battery life and maintenance against those of other UPS batteries. QPS is happy to help you figure out if lithium ion batteries can work for your environment. Contact us for an onsite evaluation today.
Published on Jan 30 2018
Last Updated on Oct 17 2023