PLC / Industrial Controls Batteries

When a controller flashes a low-battery fault, the clock is already running. That small lithium cell is what holds the program and register data while the machine is powered down, and on most equipment the line stays put until it's swapped. PLC batteries are the backup cells and connectored assemblies that protect memory in programmable logic controllers and CNC equipment — the primary lithium cells some shops call PLCC. We keep them on the shelf at Bulldog Battery in Willoughby, OH for the maintenance techs and controls people who can't wait three days on a shipment. Tell us the controller or the part number off the old cell, and we'll match the chemistry, the voltage, and the fit.

What a PLC Backup Battery Does, and Which One Your Controller Takes

These cells don't run the machine. They quietly hold the controller's program and clock while it's off, and most are 3.6V lithium thionyl chloride built to do that for three to five years before the voltage drops far enough to trip the fault. When that warning shows up, the cell is usually the fix. About one time in ten it isn't. The holder, the backup circuit on the board, or a charging-system fault can be the real cause, and our free battery and charging-system testing shows which. If it isn't the cell, we'll tell you instead of selling you one that won't solve it.

We stock the common chemistries and the OEM-fit assemblies for the controllers you'll find on the plant floor:

• Allen-Bradley / Rockwell: cells and packs for SLC 500, PLC-5, ControlLogix, CompactLogix and MicroLogix, including the 1747-BA, 1756-BA1 and 1769-BA.
• Siemens: backup lithium for S5 and S7 controllers.
• Mitsubishi: Q6BAT, A6BAT and the ER17330V-type cells behind FX and Q-series PLCs.
• Omron: C200H-BAT09, CJ1W-BAT01 and CPM2A-BAT01 replacements.
• Fanuc CNC: 3.0V lithium cells and pack assemblies (BR-2/3AGCT4A and equivalents) for your milling and machining centers.
• Most ship as plug-in assemblies with the OEM connector already attached, so you drop it in and get the machine running.

We keep these in stock because a lot of the plants and machine shops we serve around Lake County run this equipment, and when a line in Mentor or Painesville is down, a battery that's three days out is no help at all. We've sorted out DC power from the same Willoughby shop for 36 years, and most of the time we can match the right cell off the part number and have you out the door the same day, confirmed before you pay.

Stocking spares or stuck at a dead machine, come in or call, give us the controller or the part number, and we'll handle the rest. Call us at 440-942-2555 or stop by the shop on Vine St. And if a battery we sell you doesn't clear the fault, we'll make it right.