Well, actually quite a bit.
An in-depth look at why SolutionPro bets its future on batteries and why a system is only as good as its weakest link.
A well-known politician once said, “There are known knowns. These are the things we know that we know. There are known unknowns. That is to say, there are things that we know we don’t know. But there are also unknown unknowns. These are the things we don’t know we don’t know.”
Some Background Info before we get started-
UPS- Uninterruptible Power Supply. A system with 5 Major components that is used to ensure a facility is supplied with conditioned power in the event of a utility power outage or anomaly.
The 5 major components are, 1) Utility Power Grid, 2) Backup Generator, 3) The UPS System itself, 4) Batteries, 5) The Power Distribution System Components.
Now, before all you EE’s out there start correcting us please understand we’ve simplified this description in the interest of focusing on battery monitoring.
The Batteries
SolutionPro’s UPS System uses deep-cell, lead-acid battery strings to condition the power supplied to the data center. This is not an all-or-nothing proposition as many may think. Rather, visualize the battery strings as a reservoir from which power is pulled when needed. They are rarely the sole source of power for the data center, however they frequently supplement power source to the data center. Here’s how it works.
The batteries are under continuous charge by utility power readying them to carry full or partial data center load during a power anomaly. A power anomaly can be several things but we’ll limit the discussion to two of them. An under-voltage event or a complete utility power interruption.
Here’s a brief run-though for each scenario:
Under Voltage Event
A voltage deficit will cause power demand from the data center to draw from the battery strings. The batteries will supplement utility power to make up the power deficit. The under-voltage event is detected and monitored by the UPS system and the batteries will be re-charged by whatever means necessary- backup generator or utility power. Once the under-voltage event is satisfactorily mitigated, the balance of power is restored back to normal status on 100% utility power. At Any given time, the batteries will remain available as a reservoir of stored power from which the data center can draw. The batteries are an in-line parallel power supply for the data center to access whenever needed.
Utility Power Interruption
Power demand from the data center will draw from the batteries. The UPS system detects the power outage and automatically starts the generator to serve as the surrogate source of utility power. The UPS system and batteries then function as they would if they were on utility power- except the generator is now the source by which the batteries are being charged. If the batteries are fully charged, and generator power is still running during an extended outage- any voltage drops would be handled in the same manner.
As we stated earlier- there are other power event scenarios such as voltage spikes and phase mismatches but they are handled by different components of the UPS system so that discussion is for a different day.
A battery string is a set of several 12-volt batteries tied together so that they make a cumulative voltage and amperage capacity sufficient enough to supply the SolutionPro data center at full-rated capacity for a given amount of time. Exactly what the full-rated capacity is and what that given amount of time is remains proprietary information that is not published.
For the sake of discussion- view the battery strings as a series-type circuit. (this may not be exactly technically correct but it’s the easiest way to quickly understand the importance of each battery in a string)
In a series-type circuit, voltage is cumulative. If you daisy-chain together 40 12 Volt batteries you will create a string of batteries that is storing 480Volts. If one of the components (batteries) in a series is broken- this results in an open, which completely breaks the circuit- This is not a good thing in a battery string in a data center. If one of the batteries in the circuit shorts out- the whole circuit can short rendering the battery string useless. If one or more batteries in a string are neither shorted, nor opened but can not deliver rated voltage or load, that string’s ability to function at full capacity is diminished.
It only takes a few bad batteries in a string to severely compromise that string.
What’s so Important about Battery Health?
Batteries are life-limited devices. They use time-limited and volatile substances and components to store electricity. Over time, a battery’s ability to store voltage and deliver voltage and load diminishes. The problem is, every battery reaches the end of its useful life at a different time. Just when a battery checks out depends on many variables- a few of which are: charge-discharge cycles, temperature- both ambient and temperature cycling and humidity. Batteries that have reached end of life can create a short, an open, or just fail to deliver the load that is demanded of them.
Recall the power anomalies we explained earlier. Now understand that SolutionPro has redundant battery strings as well so that we are not reliant on any one string. This is one of the several redundancies built into the SolutionPro data center power delivery system. SolutionPro monitors its Data Center power consumption and growth projections to ensure its battery strings are right-sized for the facility.
Working within the Limitations
Now we understand what a battery string is, the role batteries play in our power delivery system and a few ways in which batteries can fail.
Thanks to the team that advises us on these complex power delivery issues we’ve known about the importance of battery health for a long time.
Historically, SolutionPro employed quarterly battery load/health testing of its battery strings as part of its preventative maintenance practices. This would allow us to find the problem batteries and replace them. Problem solved, right?
Not Exactly…
It turns out, detecting a bad battery isn’t as straight-forward as you might think. Batteries are sneaky devices- They can indicate full voltage but when put under load completely fail. They can pass muster one day but short out when shaken or disturbed- say for example as the tech completes a load-test and then moves it back into the cabinet. With so many different failure scenarios, It was evident that quarterly testing was not sufficiently managing SolutionPro’s risk profile.
The facilities team at SolutionPro recognized the importance of knowing, real-time, the health status of every battery in its power system. This would allow us to proactively replace a battery before it compromises a string.
| This takes us to the Midtronics Cellular Wireless Monitoring System |  |
A Panacea? Probably not. A change in the way we do business at SolutionPro? Most Definitely!! The truth is warning signs do exist about battery health. You just have to know what to watch.
The engineers at Midtronics know that if you monitor just a few different battery parameters, you can predict when a battery is nearing failure.
Those parameters are: Conductance, Temperature, Voltage, and Intercell Connection Integrity.
SolutionPro installed this system in early 2009 and it has earned its place in our facility as an invaluable asset. While we don’t publish exact numbers I can tell you we’ve already replaced a few batteries since installation.
This system has provided immeasurable value to our clients and business partners in the form of averted power issues and piece of mind.
We tend to view the UPS system and the batteries as a backup system. But this thinking de-emphasizes the importance of such a system in the future of a data center business. The power delivery system of a data center is a dynamic system that uses multiple sources of power to supply consistent, conditioned power regardless of that status of the utility company. Rather than call it a backup system, it should be viewed as a highly reliable delivery system with several levels of redundancy.
Questions about SolutionPro’s UPS System or other Related Components? Get in Touch Now
