Lithium based batteries have multiple significant benefits over alternative DC storage techniques for UPS applications:
- The technology has matured in heavy duty applications like electric vehicles and is considered ideal for critical power backup.
- Small size and light weight are the primary benefits, but additional features like built-in battery management (not just monitoring), make lithium-ion an attractive alternative to traditional batteries.
- In addition, their high cycle-count (charge-discharge cycles), and faster recharge times compared with lead batteries allows their use in non-traditional UPS applications, like grid sharing, peak shaving, and industrial or process control support.
The battery management system is deployed in each battery, as well as in a system level master controller. It manages charge current, voltage, and cell voltage balance, while adjusting as necessary to eliminate any chance of overtemperature. If temperatures rise above safe levels, the management system will independently disconnect the battery or string via multiple different disconnection means, and notify the user via the battery cabinet monitor, and an alarm on the UPS.
Overall, a lithium-ion battery system provides lower TCO through comparable Capex costs, and Opex savings via a longer replacement interval, and its ability to operate at higher ambient temperatures.