I works. I rotate it in with my other two batteries on the bike, so have only used it for one cycle. It is a little expensive for such a small battery and just in case spare battery. Wireless shifting is so much better. I have it for my 2x12 SRAM rival wireless. During the season of 2023 I was on two different rides where another rider had to cut their ride short due to a dead SRAM derailler battery. I can't remember that last time a cable broke on a ride However it did happen to me a couple of years ago, but was able to mod it to get me home.
Very expensive for a battery, but this is the price most anywhere! But now to the review. Could you get by with only the two? Sure......if your rear goes out you can swap the front which is needed less and one can have a gear range to finish a ride. However, having both derailleurs working with a spare or even two is best for very long rides. Hold do they hold a charge and perform? Well, my usual 20 mile rides daily I get up to 7-8 rides of changing the rear anywhere from 180-250 times. The front, I get longer on but only change typical 10 times per ride. This kind of shows the battery life to those wondering. I see a lot of post on broken connectors and tabs??? I wonder sometimes if people change in haste by "monkey fisting" these things rather than taking your time which in all reality is like 5 seconds to change out??? So are they worth it? Yes......unfortunately you have to drop $60 on something SRAM has to produce these at maybe $5 each and in all reality should only be like $20 tops!
Wanted to use the the Junction A bar end for a new build and did not want to mount one under the stem, primarily for a cleaner look and the fact my stem was custom painted. This split wire does what it's advertised to to do and does it perfectly. Since the bar end junction box has only 2 ports, the Y-split was needed in order to keep everything hidden.
Do yourself a favor, as I learned the hard way(fault of my own), and get the larger size, as the medium wasn't long enough for my application and internal bar routing. Oh....and get the little Shimano tool for connecting and disconnecting the E-tube wires. Worth every penny!