Originally Posted by
Steve B.
Well, its a LOT cheaper to initially replace shift cables than a battery. I tend to buy the Shimano DA pre-packaged shift cable and housing set which runs about $31 or so. A Battery is $130. A road cable maybe every 2 or 3 years ?, a battery every 5 ?. Thats what my road Di2 has on it and its still holding a multi month charge. Battery might cost more long term, but on Di2 the shifting never slowly gets worse as can happen with mechanical.
i replace the rear shifter cable once per year. when removed i can see that it is well worn near the innards of the shifter. not terribly expensive but it does add up over time. i'll be new to di2 but i would expect the battery to last more than 5 years though based on current battery technology.