BushPig (Customer) asked a question.
BEWARE!!! Click C2 Battery / Super Cap Backup
Heads up... for some inexplicable reason, Koyo have seen fit to drastically reduce the backup capacity offered by the battery and super cap.
The end result is a PLC powered off for a couple of weeks or so losing important parameters such as PID parameters etc.
This is a big deal. Consider the BRX in its place.
Can you give us more information? Did you have a battery installed and still lost data? This should not happen. You may have a defective battery or CPU. Have you tried replacing the battery?
From the manual, page 3-9.
Battery Backup
All of the CLICK PLUS PLC units have a super capacitor to maintain back up data in SRAM. The super capacitor should maintain a backup period of at least 1 hour. If you need the CLICK PLC unit to maintain data in the SRAM for longer than the above period after the power is shut off, you must install a battery in the CLICK PLC unit. Use battery part number D0-MC-BAT (not included with the PLC unit; order battery separately). Typical battery life is about 3 years, which includes PLC runtime and normal shutdown periods.
Separate by "maybe" related is I have a C2-03CPU purchased in March of 2021 kept in a travel case and every time it is powered-up after lengthy powered down periods (months) it always powers up with error LED flashing. I have to move the program switch to STOP and reload the project to get the error to clear. I checked the battery and it's fine (determined by my trusty 1980's era Radio Shack battery tester). Is there a listing of at what voltage the battery is determined exhausted/no good?
Error light will blink when battery voltage is 2.5V - 0V with SC203 = ON.
Sounds like a bad battery or Click. I've never run into that even on newer units.
The Error History or Online Project Information should be used to determine current and past Error/Warning Codes. The Blinking Error LED can indicate several different reasons, either a previous event has occurred, or a current pending warning. The PLC is in RUN mode, but may require attention. Below is some information which should help explain the various reasons for these Warnings/Errors.
When using a battery, it should be configured into the project settings