Has your UPS weathered the storm?

Power Control
12 Feb 2021

The UK is experiencing its lowest ever temperatures in over 25 years, with many counties plummeting below zero Celsius. With yellow and amber weather warnings still being issued, the country needs to brace itself for even colder temperatures and more rain, wind, ice and snow. On the 11th February, the UK recorded the coldest February night across the UK since 23rd February 1955. Things brings with it the obvious travel chaos and people scrambling to apply for cold weather payments as they find their heating bills skyrocket.

Beyond this though, businesses need to be aware of the impact this can have on them. Adverse weather conditions – heavy rain, snow and ice can lead to outages across the mains power grid leaving organisations with no power. Many choose to alleviate this risk by investing in a UPS (uninterruptible power supply) which provides peace of mind that in the event of a total outage or brownout, their operational systems will remain safe.

However, a UPS consists of numerous components that are mostly electromechanical, with lots of moving parts. Like with the mains grid, these systems operate most efficiently in the middle of the temperature and humidity range that they were designed for.

Because of this, both the UPS system and the batteries come with temperature tolerance ratings from the manufacturer for which the UPS can safely operate within. For the UPS this ranges between 0°C to 40°C but for the batteries, it’s a much narrower window of 20°C to 25°C. As the UPS ages, its tolerance to extreme environmental conditions lessens. One of the most significant impacts is on the batteries.

Whilst a UPS can operate at temperatures as low as 0 Celsius, the cold has an adverse effect on their internal VRLA batteries. A cold environment slows down the chemical reaction, increases the level of impedance and therefore forfeits performance. A battery that provides 100% capacity at 25°C will typically deliver only 50% at -18°C.

Although lithium batteries are known for their ability to handle a wider temperature tolerance than most others, very low temperatures still affect their ability to store and release energy. Like all other batteries, lithium batteries rely on chemical reactions to work and the cold can slow and even stop these reactions from occurring.

Simply put, cold batteries discharge faster than warmer batteries and so the expected runtime is significantly reduced, putting critical equipment at risk.

On the other hand, batteries operating in temperatures above the manufacturer’s guidance cause the electrochemical reaction to quicken. On average, for every 8.3°C above the recommended temperature, the battery’s lifespan reduces by 50%. Some batteries can also result in thermal runaway if they overheat too much.

The best solution is to ensure that before installing the UPS, a room with temperature control, humidity monitoring, and that contains clean air is factored into the budget. Neglecting these criteria can have severe and disastrous consequences on UPS and battery infrastructure.

Regular maintenance is key to ensuring reliable UPS performance even when installed in optimum conditions. For UPS systems installed in unsettled environments, additional battery checks and tests are recommended to closely monitor resilience.

For more information about Power Control’s UPS product portfolio and maintenance services please visit www.powercontrol.co.uk or call 01246 431431