It’s Time to Stop Using “Battery Monitoring” as an All Encompassing Term
It’s imperative to know what to measure, how, and why
If you get in enough random discussions, or are a good listener, you will sometimes hear people state, “If we pulled 10 people off the street and asked them their opinion on this topic, we would get 10 different answers. And, so it is with “battery monitoring”.
Go ahead, search for it. If you are able to find a link to a definition, it probably won’t help much.
One link I chose automatically directed me to the definition for “Battery Management System” (BMS). Then, the next link began with, “Sometimes confused with BMS (above) of which it is an essential part, these circuits monitor the key operating parameters (current, voltage, temperature, SOC, etc.) of the battery and provide information to the user.”
So it is a BMS, or part of a BMS, and many times gets confused with a BMS…ugh.
Next, I checked on LinkedIn™ Groups and the Battery Monitoring Group (I recommend it, as many knowledgeable people belong and comment), actually posed the question, “Battery Monitoring, what is it?” As of this writing, there are 14 comments, yet no one offers a true definition for the question. Some seem to suggest an “eye of the beholder” explanation.
What does Wikipedia list as the definition? Located within the definition of “Battery Management System” are the following parameters for what should be monitored.
A BMS may monitor the state of the battery as represented by various items, such as:
- Voltage: total voltage, voltages of individual cells, minimum and maximum cell voltage or voltage of periodic taps
- Temperature: average temperature, coolant intake temperature, coolant output temperature, or temperatures of individual cells
- State of charge (SOC) or depth of discharge (DOD): to indicate the charge level of the battery
- State of health (SOH), a variously-defined measurement of the overall condition of the battery
- Coolant flow: for air or fluid cooled batteries
- Current: current in or out of the battery
Now, we are getting somewhere. Wikipedia comes close to what the actual published IEEE standards recommend for battery monitoring.
Each of these measurements are integral in combining to present an accurate appraisal of readiness and capacity of a string of batteries used for the incredibly important role of providing backup power. Not a couple, not a few…each of them.
The previous sentence is the most important thing to take from this written blog. It should be read over and over again.
Here is the second most important sentence in this piece: Just about everyone who touches batteries, and can make money from the endeavor, will proclaim their systems monitor batteries. It is imperative not to act on what may be terribly deficient information or proposed solutions.
The point is, continuous state-of-health battery monitoring that meets IEEE standards has come a long way in recent years, and many times has the direct ability to save operational costs, while ensuring batteries perform as needed, when needed.
True battery monitoring is now a best demonstrated practice. But, in order to protect a company’s core business, the term “battery monitoring” must first be accurately defined and understood. Otherwise, the chosen solution could well be “worse than nothing”.