After far too many repairs, we bought a new Brita pitcher with slightly different, although apparently equally crappy, hinge pins, whereupon I bandsawed the long-failed “smart” filter timer out of the old pitcher’s lid:
The gray rectangle is the LCD panel showing how long since you last replaced the filter. It died some years ago and, indeed, the CR1616 battery was down to 2.8 V.
However, I think the real failure happened when the black square of conductive foam slipped off the switch contacts under the Reset pushbutton’s stud and went walkabout inside the timer:
That’s where I found it after sawing the casing open. I think the adhesive side should be stuck to the stud, but we’ll never know.
The new pitcher includes a different indicator with green LED status blinkies for “Standard” (40 gallon) and “Longlast” (120 gallon) filter cartridges and a red blinkie for “Expired”:
Yeah, purple. For some unknown reason, it cost 10% less than the other colors and we’re not fussy.
This one measures filter use by water volume, not elapsed time, counting the number of pitcher refills by noticing when you open the flip-top lid; the corresponding volume depends on your ability to see a nearly invisible line molded into the lid. Unsurprisingly, Longlast filters cost only slightly less than three times standard ones, so they’re not a compelling value proposition.