zOwie Omega Discussion Forum

Just a little addition.

Capacitors DO have a finite life. Over time, the electrolyte in the capacitor can break down. This can result in a decrease in capacitance. Typically capacitor life is quoted at the maximum rated tempearture and charge rate.
An average capacitor can expect to survive for 1000 hours, at 105C without loosing more than 20% of its capacity. For each 10C drop in average temp (your wrist is about 35C), the life is expected to double.

SO, 105-35=70 (7 "doublings")
1000 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 128,000 hours
128,000 / 8760 (hours in a year) = 15 years

FINALLY, since the capicitor is not likely charged at its maximum rate, you can expect several more multiples of life. (say 2 to 3 times)

SUMMARY: The watch should be good for 30-45 years before the Capicitor would need to be changed out.

How about that!! A real life application for Engineering Textbook calculations!!

: Thanks for the clarification on the capacitor
: -- I'm glad to hear this since capacitors
: typically have an indefinite duty cycle.
: When I researched Seiko's Kinetic and
: Citizen's Eco-Drive, I found that they both
: charge a small Lithium Ion cell, that will
: eventually need to be replaced, which is not
: clearly articulated in any of their
: documantation.

: Luckily, it appears that Omega's design seems
: to be more durable in nature, even though
: they suffer comparitively in duration of
: full-charge (6-days for Omegamatic vs. 14-
: to 30-days). I'll trade the shorter charge
: time ANY day, for never having to replace a
: battery!