July 9, 2010
– Completely charged my Shimano Di2 Battery. Between July and March 1, 2011 I had ridden an estimated 3200 miles. I don’t have a computer on my bike in the off season (and this was a year long off season) but 100 miles/week is a good estimate. Some weeks I rode >200 miles, other weeks I didn’t ride at all.
March 1, 2011
– Finally got the Di2 battery life indicator to go from solid Green (all systems good) to solid Red (battery is getting low <25%). The system still worked fine. I rode a bit more during this time (from March 1 to March 28) and got in about 600 miles of riding.
March 28, 2011
– Front Derailleur shut down. The Di2 system knows when the battery is getting really low <10% and turns off the use of the front derailleur – once you shift down to the little chain ring it will leave you there (I suppose if you are a manly man and never leave your big ring then you would be left there). Besides the front derailleur not working, the battery indicator light now blinks Red. You still have full use of the rear derailleur shifting during this time. Since the front derailleur no longer functions, neither does the auto trim feature so you do get some rubbing on the front derailleur. One interesting note is that some of the rubbing of the front derailleur would go away, almost like the derailleur was adjusting itself from the chain rubbing. I missed almost 10 days of riding in this period (March 28-April 21) but was still able to ride about 250 miles (w/out the use of my big chain ring) before the end of the battery.
April 21, 2011
– Full system shut down. The Di2 battery finally went into its final death throws. At first the rear shifting completely stopped. About 10 minutes later I got two more shifts and then it stopped working again. This continued for about 30 min (for a total of about 10 shifts) until it finally threw in the towel.