Powertap G3 - Oddities and Updates

This past Saturday I went through my pre-ride ritual of preparation and one of the last steps is to "zero" (Garmin calls it "Calibration") the torque offset value. Typically this value falls in a certain range like 500 to 520. Mine typically shows a value between 496 to 500. I feel good with that range since I have completed a static weight test and found the hub to be within 2% accuracy.

The image below showing a value of -22281 was what I saw in the field just before the ride so I turned the power meter off in the Garmin 800 and did the ride old school with just the basic metrics derived from the GPS.

When I got home I first uploaded my data and created a blog entry. The wheel had been sitting dormant in the garage for about 45 minutes. I turned both the 500 and the 800 on before walking down to the garage and before I opened the door both units detected the hub. This is not supposed to happen! The hub is supposed to go to sleep after a few minutes of non use and to be honest it does most of the time. I cannot remember a time in the past since updating with Firmware 16.000 that the hub was detected without spinning the wheel to wake up the hub. Nonetheless this time it was still awake. 




















A few moments later the Garmin 500 gave a low battery warning.

 





 

 

Trying to keep calm about it all, I checked the PowerAgent application and it gave me a clue that a new firmware update 16.056 was available. It was a simple process to follow the steps in the application and install a new battery as well.

 




















Next step is to wake up the hub and see if the offset value looks back to normal

I finished with several tests to see if the hub would go to sleep, wake it up and repeat. The G3 hub looks to be in good working order again. It performed well in today's ride and hopefully there will be a touch more battery life as a bonus.

I do like having the ability to do these firmware updates at home without the stress of boxing up the rear wheel like the older PowerTap hubs and send it off for repair or a rebuild. What I have learned from this experience was to check more often for the firmware updates.

From PowerTap
http://www.powertap.com/pages/firmware-release-history

G3 Powercap

Current Firmware 16.058, released March 26, 2014
Release Notes: 

• Added a reset after sleep to cure zero power issue. 
• Changed low battery warning values.