How to install a PLC Battery

In this article we will cover how to install a PLC battery. If you are in doubt you should contact the manufacturer of the PLC equipment for clarity on your particular model.

Most pieces of PLC equipment have lights that indicate how much voltage is left in your Programmable Logic Controller (PLC) battery. When the light turns yellow or red or indicates low voltage, it is time to change your PLC battery.  Lithium Programmable Logic Controller (PLC) batteries are designed to provide back-up power to the processors memory. Processors draw power from the Programmable Logic Controller battery to retain information in situations where power is lost for 30 minutes or less.

To replace a PLC battery:

  • Locate the PLC battery on the processor module.
  • If the PLC battery is on the front of the module, leave the PLC plugged in. If the battery cannot be located without removing the module, unplug the PLC power supply. This will mean the PLC will have to be reprogrammed, but this will avoid electrical shock to the technician
  • Pressing the retainer clips on the top and bottom of the module should allow it to release and slide out.  This step may not be required if the battery is located in the front of the processor module.
  • Unplug the PLC battery connector and remove from the unit.
  • Inspect the replacement PLC battery to be certain that it is identical to the original in voltage and size.
  • Plug the new PLC battery connector into the socket and secure the battery with the retaining clips.
  • Slide the processor module back into the chassis firmly until both retainer clips engage.
  • Restore power to the PLC
  • Dispose of the old PLC battery properly.  If the battery is damaged or leaking electrolyte it is recommended that it be put in a polyethylene bag with 1oz of calcium carbonate, then placed in yet another polyethylene bag and heat sealed.  You would then need to contact a battery disposal company to properly dispose of.

These general instructions and precautions should allow you to safely replace the back-up battery in most PLC applications.

Your average PLC battery will last anywhere from 2 – 5 years according to the type of processor, how much the battery is used and the environment it is in.

Was this article helpful?

Related Articles

Leave A Comment?