Nachoman

With my old external Di2 battery, I was getting around 1,500 miles per charge.

With my new internal seat post battery, which I got a couple years ago, I’m now down to about 500 miles per charge.

Anyone else having this issue of decreased mileage per charge?


Edit: 10\5\15.
My front derailleur was acting strange. It shifted perfectly, but started making some weird noises. After the shift was completed, it would make a ticking noise, like it was auto adjusting. Those of you with Di2 know that sound. Anyway, I took it into my mechanic and he took the front derailleur apart and cleaned it. It no longer makes that weird noise, and he said that I should now probably get a longer battery charge life.

softreset

It's difficult to compare Di2 charge life to mileage, you really want to compare it to number of shifts (which is obviously much harder).

I've had as much as 1800 miles off a charge and as little as 600 miles off a charge (same battery, same bike), whereas the 600 mile charge came first.

It's all about how often those derailleurs (terrain) are changing.

DaveWC

Mine seems to last forever. I put about 6,000 miles per year on my bike & I charge it maybe twice a year. Pretty flat where I am though. I shift gears much more often in the winter, indoors on rollers trying to keep up with the Sufferfest attacks.... (just another reason that indoor miles are counted by me)

SpeshulEd 

I'm around 1000-1500 with the ultegra external battery. Maybe a bit more if I'm lazy and don't climb as often as I should.

gc3

If you get the new shimano doohickey which tells you which gear you're in (on the garmin) it also counts the number of shifts, and they are shown in ride summary. It also provides status of the battery at 10% intervals. So you never ride in doubt unless you're just one of those risk-taker types.

rpenmanparker 

Who cares? I don't keep track of my mileage for any other purpose. I certainly wouldn't keep track of it to know how far I go on a battery charge. BS.

Heathpack 

You're not getting enough miles out of your battery, no matter how many shifts you are making (besides the fact that you're probably not shifting way more since getting your internal battery). You should get around 1500 miles between charges.

I have had this happen twice on the same bike over around 10,000 miles of riding. Shimano says it's very rare but I wonder how rare it actually is.

My experience is that you start out with the full 1500 miles between charges and then it goes to 1000, then 750, then 500.

Call Shimano. They will act shocked and will probably make you jump through some hoops. But in the end, they'll do the right thing and send you a new battery.

Nachoman

I do.

Who cares?

I don't care.

rpenmanparker 

Your candor is refreshing.

bt

wait til the sram wireless comes out.

there will be lotso new threads on battery(s) life.

f4rrest

About a month for me.

Lost the FD shift in the middle of a hilly 100 degree 65 mile ride Monday. Then I got nervous about losing the RD, so stopped shifting much, mashing more.

Hate it when that happens.

Vicegrip

I have said device on my primary road bike and found it drains the Di2 battery at a notable rate. Not so much as to be an issue for a long weekend or the like but the battery life is measurably less when running the Di2 sender. I also have a tandem and can see where the ability to see the gear I am in to be a very good thing when the front derailleur and rear wheel cogset is not an easy peek.

D00d... Is there a non self gratifying reason to your post? This thread started with a valid question of interest to those that run Di2 and the subsequent posts were informative and on point. You seem to feel the need to blurt. Do you even have a Di2 system? If not please stand aside and let those that do have a conversation.

rpenmanparker 

Yes there is a non self-gratifying reason for my post. I am crusading for common sense, and I have a valid point. If you plug the battery in every now and then (what, once a week for a few hours), you won't have to worry about the mileage between charges. What possible reason could there be for trying to squeeze mileage out of the battery besides vanity. "My battery lasts longer than your battery". Total BS. Just keep it charged and cease thinking about it. Just set up an extension cord to reach up to your bike wherever you having it hanging and plug it in from time to time. Done and done. This is not rocket surgery.

Vicegrip

should get about 300 rear der shifts after the front der shuts down per Shimano. Been there once intentionally. I had a usb booster pack along for a long, self supported, hilly, multi day ride and knowing the di2 system was getting low I decided to see how well the built in fail safe system worked. Front der got notably slow to shift for a good many miles then stopped in the big ring. Rear der sound shifted down a bit bit kept on working. I plugged in the USB to anything booster for 20 min while at a rest stop and the Di2 system went to 80%. All function back to full normal and it even regained the proper sound. I find you can hear the system when the battery is getting even close to low. I found there there are many other things to think about than the Di2 power supply. It seems to simply work and work well.

Vicegrip

Do you even have a Di2 system?

rpenmanparker 

Nope. Now you can gloat. But exactly what difference does it make? Why would you purposely hold off charging your battery just to see how badly inconvenienced you can be when it fails. I say it again, BS.

bt

make sure the rear derailleur has some room at the small end of cassette to overshift.

DaveWC

I think it would be stupid to charge the battery weekly as you advise. You can test the battery by simply holding the right gear shift & looking at the light. Charge it when it's red. I believe the reason for the question in the OP is to determine if the battery is defective. I see no indication that it's for bragging rights. If the battery should or used to last 1,500 miles & now it lasts only 500 that indicates something is wrong. Heathpack indicates that this could be a warranty issue & a new battery could be due. No idea why you'd care about this given you don't have this equipment.

bt

do you even Di2, bro?

Vicegrip

Not gloating at all. My annoyance with your posts is more due to something more plebian. It means nothing more than how about you not interrupt a conversation that Di2 owners are having about Di2 systems with non pertinent uninformed unhelpful opinions? For your post to be of any validity to us Di2 owners you would have to assume that we are all lacking in basic common sense. Do you truly think you are smarter than all the rest of us? That something as simple as plug in now and then is a concept beyond Di2 owners comprehension? Please.... The Op asked a question and other Di2 owners were chiming in. During the next cable shift related question please feel free to add.

rpenmanparker 

The battery is two years old and could be suffering from "memory" issues which afflict even the most modern batteries. I wonder if the battery warranty is long enough to still cover it.

If it has to do with bikes, I'm interested in it even though I don't own all the equipment that's out there. Hobbies are like that.

Heathpack 

I love Shimano because they have huge confidence in their stuff. They are always SHOCKED when something of theirs does not perform flawlessly. The pleasant side effect of this in my experience so far is that once they are convinced that their product has a problem, then are easy to work with, they just help you out.

Granted, I had two batteries fail in the first year I had the bike, which is clearly a problem. I'm not sure how many miles @Nachoman put on his dying battery, or exactly how long the warranty lasts. But I do know the best way to find out is to call Shimano.

Vicegrip

By modern do you mean LIPO? LIPO batteries don't suffer the same memory issues commonly seen in (much) older systems such as Nicad. There does seem to be an effect that is far less an issue and far easier to work around. In fact the charge discharge format seen in the Di2 system is spot on for LIPO longevity. That is unless you needlessly charge the battery from a near full condition as you previously recommended as common sense. Even then the shimano integrated voltage protection and charging system keeps the battery in well defined use profile brackets.

An interest and something positive to add are not one and the same.

rpenmanparker 

Yep. And you're right, LIPO batteries are much better. But not perfect. A couple of folks besides me have suggested that charge capacity appears to degrade over time and usage. I'm just saying that it may be a characteristic of the batteries. If it happens fast enough, it seems Shimano will replace the battery under warranty. There doesn't appear to be any information about the handling of a slower degradation posted yet. It should be worth a try to get Shimano to help out. That was pretty positive, doncha think?

Heathpack 

Just to clarify: Shimano never asked me how old my battery was or when I bought it. The first failure, they required multiple trouble-shooting steps. The second failure, they just sent a new battery out.

My replacement batteries have been sent through a different LBS, not the one I originally purchased the bike from.

I would be surprised if Shimano hassles OP about this. I could be wrong, would love to hear back from OP if he does talk to Shimano.