scarleton

A video of what I am seeing:
Folks, I have two Shimano Di2 External Battery SM-BTR1 for my Di2. I just checked the levels on the one on the bike, it was flashing green (50%) so pulled the other battery (which was the older of the two) from the charger and placed it on the bike. When I checked the second battery, which should have been 100%, it flashed gree for 2 seconds and then the OTHER LED came on and was RED at the EXACT same time the first one was GREEN. I dug up the manual (UM-7FE0A-005-00-ENG.pdf) and found this:

100% - Illuminates green (for 2 seconds)
50% - Flashes green (5 times)
25% - Illuminates red (for 2 seconds)
0% - Flashes red (5 times)

But I cannot find any info on when it is both GREEN and then RED at the same time. I am guessing that the battery is at it's end of life, but thought I might see if anyone else knew. (I will be taking both batteries on the 400k I am doing this weekend!)

Here is my blog on my 300k from last weekend: https://adevelopingxtian.wordpress.c...ssful-failure/

TimothyH

There is a definite lack of information about what the lights mean apart from the 100/75/50/24% status lights.

Shimano is pretty tight-lipped and I've not seen the code broken anywhere.

gmarsden

With new firmware, after the battery status green LED code, it flashes both the red and green together one to three times to show the current shift mode. Typically manual, semi synchro and synchro respectively.

sch

see also: Technical FAQ: Using Di2 Synchro Shift | VeloNews.com
According to the article the BTR1 battery does not support synchro-shift, but evidently your firmware was
updated, hence the dual light display, as per gmarsden.