Lithium-ion batteries find their way into datacentres

Lithium-ion batteries are finding their way into uninterruptible power supply (UPS) systems as more datacentre operators look to reduce their footprint and energy consumption as part of their sustainability efforts.

Compared to valve-regulated lead-acid (VRLA) batteries that the datacentre industry has been using for decades, lithium-ion batteries are smaller and can reduce datacentre real estate by up to 40%, according to Carlo Quiriconi, industrial applications manager at Vertiv in Australia and New Zealand.

Also, lithium-ion batteries tend to have a longer lifespan of up to 10 years or more, compared to three to five years for VRLA batteries. Along with their ability to operate at higher temperatures, thereby reducing cooling costs, they could lower the total cost of ownership (TCO) for datacentre operators.

Quiriconi said the biggest users of lithium-ion batteries in UPS systems have been the largest colocation datacentre operators, followed by enterprise datacentres where about 10-20% are already using lithium-ion batteries. He expects lithium-ion to become mainstream in datacentres in the next five years.

“Those in the colocation and hyperscale space are looking for much longer returns and they don’t want the trouble of having to replace batteries,” Quiriconi told Computer Weekly. “Even installations that currently have VRLA batteries are switching to lithium-ion, so this idea of long-term cost of ownership is something they’re very much looking into.”

On concerns about lithium-ion batteries catching fire, Quiriconi singled out the differences between lithium-ion batteries fitted in consumer electronics and those used in UPS systems.

“In consumer electronics, you’re often trying to have maximum runtime in a very confined space – and cooling becomes an issue when you’re trying to work with constrained space,” he said. “For applications in the IT space, we don’t have to package things small. In fact, we package them in a very open space to give the batteries plenty of air.”

Furthermore, lithium-ion batteries are well-managed by sophisticated control systems that monitor temperatures and have multiple layers of internal safety construction based on strict industry guidelines, Quiriconi added.

But as lithium-ion batteries cost more than their VRLA counterparts, they tend to be better suited for shorter battery autonomy times – a measure of how long a battery will last for a given load during a power outage.

“If you have an eight-hour or four-hour autonomy requirement, VRLA is still going to be a much more cost-effective solution over lithium-ion,” Quiriconi said.

Still, in underground facilities where ventilation might be an issue, Quiriconi said lithium-ion would be a safer choice than VRLA.

That is because VRLA batteries produce hydrogen when they are being charged, and the hydrogen gas must be expelled to prevent explosions which could be disastrous in an underground environment.

Quiriconi said existing UPS systems can be fitted with lithium-ion batteries in most cases. “We just have to make sure that the charger and batteries are well accommodated. On a few occasions, we have been asked to employ lithium-ion in lieu of VRLA after the customer had the UPS running with VRLA for seven or eight years.”