If you are on the hunt for a new UPS battery, you may be wondering exactly what is out there to choose from. There are three main types of batteries used for UPS, or uninterruptible power supplies: Lead-Acid, Nickel-Cadmium, and Lithium Ion. There is not a single “best” type of UPS battery. The choice of which one to use should be made on a case-by-case basis. In this blog post, we will explore the three types of UPS batteries so you can determine which one is best for you.
Lead-Acid UPS Batteries
Lead-Acid batteries are known for their reliability when used in a UPS, and that alone has made them a popular choice of UPS battery for quite a while. They are also the most economical choice when weight is not a concern, like in large power applications. Their cost-effectiveness combines with high tolerance and low internal impedance for a smart battery choice.
Within the Lead-Acid battery family, there are two subtypes:
Valve Regulated (VRLA): This is the most common type of battery found in modern UPS systems. Also known as Sealed Lead-Acid (SLA), these batteries typically come with a 5 to 10 year design life. They are best suited to a dry and climate-controlled room that is kept at a temperature of 20-25°C. They can be mounted either vertically or horizontally, which means they can be used in battery compartments, rackmount trays, or cabinets.
Open Vented (VLA): These batteries contain plates that are flooded with electrolyte acid, so they are commonly referred to as Flooded. Their design life is up to 20 years, and they are usually used in places which need a high ampere-hour (Ah) rating. This type of battery must be placed in a dedicated room equipped with wash-down facilities in case of an acid leak, and they must be kept upright.
Nickel-Cadmium UPS Batteries
Formerly a popular choice of telecoms installations, Nickel-Cadmium (NiCd) batteries are still used in locations with very high ambient temperatures. Additionally, they are able to handle a wide ambient temperature range of -20°C to +40°C. They offer the advantage of a 20 year design life, a long life cycle, and tolerance of deep discharges.
But they are more expensive than VRLAs, and the toxic materials with which they are made makes them hard to dispose of. Many countries have outlawed or severely restricted the manufacture and usage of Nickel-Cadmium batteries for this reason.
Lithium-Ion UPS Batteries
Lithium-Ion (Li-Ion) batteries have been the standard for laptops and smartphones for a long time. Now they are being used to propel electric vehicles into the future. Because of this rich history, they are becoming an increasingly viable option for UPS.
They have higher reliability than both types of Lead-Acid batteries thanks to built in monitoring and management systems. They are also smaller, lighter, and have faster charge times than Lead-Acid and Nickel-Cadmium batteries. And finally, their longer service life balances out the increased upfront capital cost to purchase Lithium-Ion batteries.