Choosing batteries that are not ideal for a given application can undermine resilience, putting businesses at risk. Jon Bailey, managing director of Hoppecke UK, offers some advice on ensuring optimal protection for mission critical sites
We are living in times of increased business risk and one of the key issues for many businesses is that of the security and continuity of energy supply. The possibility of energy-related failure is very real and is of increasing concern. More than half of decision makers expect to experience an energy related failure in the next year and eight out of 10 businesses have experienced such a problem in the past year.
Whether the cause is deliberate attack, equipment failure or extreme weather – the cost is huge. It is estimated that businesses without an energy resilience strategy are risking 17% of their revenue, or £2.8m each year, in damage and lost opportunities.
An outage of one day would be catastrophic for any business, but for those with critical systems or companies whose livelihood is data – banks, insurance companies, financial institutions – the effects of a power outage, be it a brownout, blackout or permanent fault, are even greater. Not only does it disrupt their business operation due to unscheduled downtime, equipment damage or lost inventory, but it also means that vital data could be lost. And then there is the damage to brand and reputation and relationships – and even lives.
In commercial applications such as data centres, there is not as much regulation surrounding the safety control systems for UPS as there is in industry, for instance, in power transmission applications. Nevertheless, a good UPS system has to be at the heart of an energy resilience strategy to ensure data security and protect the business. It is effectively the best insurance policy available. But what most businesses do not realise is that the best UPS system is only as good as the batteries that power it.
A typical 140kVA UPS system – the size required to provide reserve power for a medium-sized insurance company – will require up to 128 valve regulated lead-acid batteries, either in a separate room or housed close to the UPS system itself. At £20,000 for such an installation, the cost of the batteries can be as much as the cost of the UPS system itself, and therein lies the risk and potential downfall of the entire energy resilience strategy. It can be easy to overlook the importance of the battery and use cheaper or smaller products in an effort to save costs and reduce the price of the overall UPS system.
When an organisation is planning a new UPS installation or needs its current system upgraded because it has reached the end of its design life, it typically goes out to tender to companies that specialise in UPS. They then recommend third party battery products as part of the installation, and this area can be seen as a way of saving costs. But choosing batteries that are not ideal for a given application will undermine everything the system is built for and could put the business at even greater risk.
High quality batteries will have a design life of up to 12 years, due to the build quality of the battery product coupled with how well it is maintained.
In comparison, cheaper, poorly maintained or incorrectly specified batteries can have a design life of as little as five years and suffer a 20% to 30% reduction in the ability to deliver the promised ampere hours. This gap in performance can present a huge and unforeseen risk to an organisation.
The old adage ‘you get what you pay for’ is no truer than when it comes to design life of batteries in mission critical power applications. Quality is paramount. Considerations should be given to the build quality of the batteries. This includes the way they are encased and designed as well as the type of electrolyte used. Some of the best quality batteries use flat plate technology and absorbent glass matts to fix the (gel-based) electrolyte and ensure more efficient transference of energy for higher current capability. With this type of technology batteries do not need refilling with water to top up the electrolyte, and don’t vent gasses, thereby requiring less maintenance and space.
Valve regulated batteries, which account for the majority of UPS applications, are designed to work with tight parameters on voltage tolerances and temperature. But expert consideration is needed to match the size and type of the battery with the load size and design time of the system.
This area is another potential minefield when it comes to risk of power outage. For mission critical load sizes of 400kVa or higher, a larger size of battery is needed, sometimes up to 1000 Ah, especially if the time period required to support the system runs into hours rather than minutes. Here, a single string of batteries will often not do the job. So it can be tempting for the UPS designer to recommend multiple strings of smaller batteries to keep costs down. But this poses problems in term of charging and maintenance and the risk of thermal runaway, which can literally cause the heart of the entire UPS system to go into a dangerous meltdown.
Specifying the perfect battery for mission critical power involves not only matching the capacity of the battery to the load of the system but considering how many minutes or hours it needs to support reserve power and how many watts are required to deliver over that time period in the event of a power outage.
While maintenance of modern valve regulated batteries is minimal, it is still important in maintaining the design life of the build. Modern valve regulated UPS batteries are designed to be a sealed, touch safe unit encased within a solid shell.
As the inside of the battery cannot be seen or accessed, maintenance is an expert art. It includes a visual inspection of the case itself, as well as voltage and impedance readings which, if taken on an annual basis, year on year, for consistent comparison will provide an indication of whether the cell is deteriorating.
It takes an experienced engineering professional to maintain such equipment, as much of this is down to the engineer’s experience of working with and servicing batteries.
Given how critical power outage can be for data-driven businesses, no insurance policy is better than choosing and maintaining the right batteries for each installation. If this is not observed, the UPS might as well not be there, as there will always be the risk that it won’t be up to the job when it is needed.
Putting the battery at the heart of a reserve power installation by making the right choice of battery supplier and maintenance provider should be a key component of a robust energy resilience strategy.
Case study: Police Mutual
To maintain IT connectivity and data safety, the police force’s not-for-profit financial services organisation entrusted its reserve power supply to Hoppecke. The 10-year old batteries powering two systems at the Police Mutual Assurance Society’s headquarters in Lichfield, Staffordshire, had reached the end of their design life, so the society decided to upgrade its UPS capability. One set of 62 blocs of grid power VR M 6-170 batteries were installed in the 60kVA UPS system and one set of 66 blocs of grid power VR M 6-170 batteries in the 80kVA UPS system.
The Police Mutual Assurance Society had space constraints when it needed to upgrade its UPS capability in a basement facility. The installation included removal and recycling of the old batteries. Batteries are heavy, sometimes weighing up to 65kg, so manual handling was not an option. Hoppecke’s field engineers deployed a scissor lift to gain access down a stairwell and manage the installation of one set of 62 blocs of batteries and another of 66 blocs. Just one day was allocated for the changeover.