Yes, I can hear it now- 'it depends'. Tell us your experience with these small batteries used on simple bicycle computers.

I'll start.

I've just replaced batteries on both my bikes, after about 6600 miles/I guess a little over two years.

My 105 Di2 shifters use two 2032 batteries in each shifter...I got nearly two years of use on the rear shifter when I got a low battery warning light...still worked fine. Front derailleur shifter is still working with the same batteries it came with.

It really comes down to is the battery getting used all the time. That’s not the case with DI2 shifters, they only draw when you shift then lay dormant. I’m 7 mos on my DI2 shifters and the battery level display still shows full. Unlike an Garmin speed sensor that is constantly transmitting during a ride, I find they don’t last that long.

My wired computers, lasts or years. Wireless, does not last long at all, usually less than a year.

Lots of other comments at this link:
CR2032 Batteries

Usually wireless computers you are probably changing once a year or so. Wired usually take a longer time. With other stuff it can vary quite a bit.

Over 30,000km on Cateye wireless sensors. About half that on the computer itself.

My 4iiii power meter uses them fairly fast, I need to change about every 9 months.

These cells are used in gadgets that draw little current in short bursts with long periods between use. They don't lose much charge when idle. That's why they last so long.

It does depend....

They last less time in cold vs. warm weather.

They last less time the more miles you ride.

It's not a time factor it's a use factor.

Had a fishing buddy of mine that would brag how a certain brand of wading boots would last 5-8 years for him. Mine would last about a 2 years. The difference...He fished once or twice a month. I fish 3-4 days a week.


The mailman's brake pads won't last as long as mine either....

Wired computer, probably 3-5 years. I don't even track them, and I'm a bit AR about logging replacement things on a bike.

Wireless sensor/computer? Usually less than a couple years, though it depends on usage.

About 10 years !!!

The ones I have say "2033" on the package.

Barry

Generally 4 Years on my Sigma wireless.
The battery of the speed sensor on the fork 6 Years so far.

boy... I'd say that I get at least 6 or 7 years of use in my Cateye Mity or Velo wired computers.

I've looked up the datasheet for a Duracell in the past. I'm surprised that there is no mention of the shelf life. It does have discharge curves for two resistive loads that are much greater than my Cateyes....



The listed life of about 1100 hours is only 45 days (if my math is right). That's far less than what I've seen on bike computers. The computer itself draws very little power, due to the cmos circuitry and LCD readout (I'm avoiding saying "LCD display", because that's redundant).

The main power draw on these items is the pull-up (or pull-down?) resistance used with the reed switch that is the sensor. It only draws power when the magnet goes by the reed switch and closes the switch. If you want to get the longest life, try to avoid parking the bike so that the magnet is near the reed switch.

I've got a few bikes with the old Avocet computers. These use the magnet ring at the hub and a coil of wire as the sensor. The circuitry is always active, and they go through a 357 battery in a year or less. The Cateyes are sooo much better in that regard!

Steve in Peoria

about 7 months on my HRM.