Adding my experience here, my IC40 appears to have stopped working in the last 7-10 days.
When I checked chlorine last week, I was at ~ 1ppm, and the check cell light was flashing. I cleaned the cell and boosted the percentage and pump run times since temps are getting warmer.
This morning, chlorine is reading zero.
Checked the cell life, and it shows 2 out of 5 LEDs, which should indicate approximately 60% life remaining.
The cell has lasted for a little over 6 years (with a couple of flow-switch replacements), so I'm not too upset. It's still frustrating that these cells don't seem to even get close to their 10,000 hour rating.