Changing Your PLC Batteries Regularly
Your programmable logic controller (PLC) is the focus of your automation processes; the engine that runs the machine. During power outages your PLC needs backup power to support the processor’s memory and protect necessary data and information. Check in with your systems integrator to learn more about the products you have in place or to help choose a controller and power source just right for your design.
Lithium batteries have the capacity to provide this power, but must be replaced regularly in order to function as intended. Just as an airplane taps into a reserve fuel tank when its regular source of fuel fails, your PLC needs a reliable battery to provide energy in crisis situations. Without reserve fuel the airplane could malfunction or crash, and depending on the functions managed by your controller, a battery failure during a power interruption could present issues just as catastrophic.
Typical lithium batteries last between two and five years, and are manufactured by companies like Allen Bradley and Seimens. The life of the battery will vary based on the type of processor it serves, as well as the frequency and amount that it’s used. Your systems integrator can help you choose the best option for your process.
To ensure that your processor batteries are effective you can check the battery indicator located on the front of your PLC. Writing the installation date on the inside of the battery’s cover is considered a best practice, so you can also reference this date to estimate the age of the battery and gauge whether or not it’s time to replace it. Some processors contain bits featured in their status files that can be programmed into the application to automatically alert personnel of a low battery issue.
Battery Replacement Tips
When you replace your PLC batteries, please consider these tips:
- Touch a grounded object before handling your processors to avoid electrostatic damage.
- If you’re dealing with SLC 5/01 or 5/02 processors, remember not to power off the device before removing the battery. Application code will be erased if they battery is removed while the PLC is off. As a rule of thumb, do not keep any processor’s power off while the battery is removed for more than 30 minutes.
- Avoid handling ruptured or damaged batteries with bare hands, and wear a protective face mask to keep from inhaling any fumes.
- Always remember to properly dispose your old batteries.
Remember, the application data that your processor contains is worth quite a bit more than the cost of replacing lithium batteries. Make sure to keep a record of timely battery inspections, and keep replacements on hand. To find the right battery for your PLC, browse some of the resources below:
PLC Battery Retailers
How old is your PLC battery? Are you protected from a power outage? If these are questions you don't know the answers to, then contact us for your PLC battery questions.