Fresh batteries installed in your processors help protect against data loss should you ever lose steady power. It is a good idea to check the battery meter on the front of your processor and take note of the installation date printed on the battery. Anything older than 2 years should probably be changed as part of your routine maintenance plan. Any expired batteries should be replaced immediately. When one calculates the true value of your application code or the downtime cause by the interruption to your business, the cost of replacing older PLC batteries or having some on hand for the time you really need them - the price of these batteries is miniscule.
Programmable Logic Control Batteries are used in many critical business machines. Almost every factory or large warehouse will have some type of PLC battery back up for automated industrial robots, automatic lighting systems, conveyor belts, CNC lathes or CNC milling machines. Batteries Direct carries PLC batteries for all Allen Bradley, Siemens logic controllers, Fanuc, and GE - you name it. As mentioned earlier, a PLC Battery is generally used to backup critical programming instructions that you have invested a lot of time, money and energy to create - so don't forget to order spares.