Originally Posted by
JohnJ80
You don't need to charge eTap "every few rides" unless your rides are 200 miles long. It's about 600 miles between charges on a fresh battery. Di2 for me was about 1000 miles and you can't have a spare battery with a seat tube battery. The eTap battery is tiny as far as carrying a spare.
While Shimano has done a decent job on the cabling, it's still a fact that interconnections on electronic systems are one of the prime sources of reliability problems.
J.
Every few rides does sound a bit ridiculous.
According to SRAM, their battery lasts 60 hours of riding (Probably about 6-900 miles) Shimano says their battery lasts 1242 miles.
I am not sure the need for a spare battery, unless you have a older/cheaper head unit that doesn’t communicate with an electronic system. I have a Low Battery notice that pops up on my Wahoo when the battery is getting low. The wire connection would be internal, which makes it very doubtful that there would be any kind of issue.