MikeOK

Ive had my bike with di2 for 5 months. I ride 60 miles/week. It finally got down to 50% today. I could probably go another 3 months on it but I went ahead and put it on the charger mostly because I’ve never done it. So you di2 naysayers take note.

Doge

I typically charge 1-2X a season.
5 Di2 bikes. Of course some only one time.

wthensler 

Yeah, they last a while with a single charge. Both of mine are 5 years old, and I've only been caught short once. I simply forgot to charge it. But if you ride more and in hills (more shifting), it will require more charging.

MikeOK

I have a question for you guys. Does the yellow light go out when it’s fully charged? And what is the other light for, the one with a battery symbol and an exclamation sign? My light went out in a little over an hour, was surprised it charged that quick.

f4rrest

It's done.

brianmcg123

Those lights are charge indicators?!

I thought they told you when you needed a new bike.

MikeOK

I wonder if my wife would buy that story

Seattle Forrest

I only get about 600 miles to a charge. That's with the new battery that you need for synchro shifting, etc.

FeltF2Tarmac

Charge mine twice a year if it needs it or not. I was told the D Fly would drain battery quicker but that has not been my experience. That synchro shifting doesn’t interest me and hearing about the battery life solidified that for me.

pesty

You say that... right up to the point that you run it dead 10-15 miles from home and have to ride back single speed and you were going up hill in 36/17 when it died. This has happened to me exactly once.

I now charge mine once every month or two. My lights/cameras/PM get charged daily, so I setup a charging station in my garage where I store my bike. Makes it relatively easy.

Seattle Forrest

I don't know the capacities on the two batteries, but I live in a very hilly place and shift a lot as a result. According to my Garmin, I make 200 - 300 rear shifts per hour of riding. (Multi-shifts count as several, shifting in the front gets you two rear shifts with it.) So it's probably not that the new battery is awful. At least don't take my experience as the norm.

I'm shocked how much life everyone else gets out of theirs.

FeltF2Tarmac

Very hilly here in lynnwood as well, just a short drive from Seattle. I know I shift quite a bit but it’s more like three or four times that mileage. I suspect the greater use of the front derailler with the rear is the culprit. I’m stubborn and if I had not got the incredible deal I did, charging my bike wouldn’t cross my mind because I was a nay sayer on Di2 until I tried it. Not sure how many times I shift an hour but I will estimate it’s not 300 maybe 200 is accurate. I know your into those scenic mountain rides so that may have something to do with it.

FlashBazbo

SF, I think you must lean your bike against a shift button when you put it away. I live in a mountainous area, too, and I get between 2,500 and 3,500 miles on a "half" charge. (I plug it in whenever I start to get the half charge indicator.) The generation of battery doesn't seem to impact this much.

Seattle Forrest

Sounds like maybe something is wrong with mine then. It can't be the wireless transmitter thing, can it? (That's how I know how often I shift, my Garmin counts for me.)

TimothyH

On the first charge mine lasted 800 miles before it was at zero and the FD failed.

This was unexpected and not consistent with what others were saying at the time and are saying in this thread re discharge time. It had me similarly concerned and as suggested I thought I might have leaned the bike with the shift button depressed or that the FD was somehow actuating all the time.

Having been fully discharged and now on the second charge it has gone 400+ miles and is still >75%, solid green on the indicator. I believe that the Shimano batteries discharge quicker when new. At least that's what it seems like.

Given my experience I'd ask how many times you have charged and whether you have let it completely discharge (or get very low) prior to charging at least once? Might be worth trying.


-Tim-

Nachoman

No. Just the opposite.

FlashBazbo

I'm not sure about the impact the wireless transmitter might be having. I didn't like Synchro Shift, so I didn't leave my transmitter on the bike very long. It obviously uses SOME electricity -- I'm just not sure how much.

TimothyH

I'd like to see forrest drain his and then charge from empty to see what his experience is.

FeltF2Tarmac

If you are referring too the D-Fly it had very little effect on mine discharge wise. Not completely clear on how Synchro Shift works but i don’t have it and from what I have read that’s the only variable in our setup.

Slick Madone

I had mine fully charged 3 few weeks ago and the FD died today when I just started a ride. Charging it up see if that alone was the culprit.

f4rrest

I dipped mine in hot wax. Now it lasts 3000 miles.

JohnJ80

I also ride in a hilly area and make about that many shifts - which I found surprising. I had no idea I shifted that much. Your experience parallels mine. When I went to the new battery, I now get about 600 miles instead of around 1000. The reason I went to the new battery was to be able to fiddle with all the Di2 parameters with the e-tube software.

I just set up a bike with an e-tap retrofit. I have to say, that's a really nice set up and I almost prefer it over the Shimano Di2 stuff.

J.

matt92037

My mileage dropped significantly when I switched to the new battery. My battery had very short life and serious issues taking a charge when I plugged the Shimano charger into a usb wall plug adapter from one of my tablets.

I had read somewhere using usb/wall plug adapters is problematic. Once I started plugging the charger back into my MacBook to charge I have not had any issues.

Seattle Forrest

Me too! It sounds crazy.

Thanks for sharing your experience, I guess that pretty much confirms it's the new battery after all.

Seattle Forrest

The bike came with the older battery, but I had it changed before I took it home. It was pretty easy for the first charge because I took it home, filled it up, and the battery was close to the end with a little under 600 miles on the odometer. (It was around 20 %, I didn't want to get stranded in one gear out on the road.) I've topped it off a couple times since when it's gotten low-ish, but I haevn't let it go completely empty, or get close.

I'd be happy to do it for science. I'm pretty convinced by what John had to say, but, still, let's find out.

I don't think synchronized shifting has that much to do with it, I don't shift in the front nearly as often, and it shouldn't be draining the battery when I'm not using it. But who knows. (I might turn that off, I have a love/hate relationship with it.)