Ultegra Di2 battery issue

[sil3nt]

Hey guy's not sure if any of you have come across this before but I have watched my Di2 battery gradually decline in performance more so when I have not been riding the bike over winter as most of my riding has been on my steel fixie.

I knew the weather was going to be nice in Perth today (for a change, damn rain and wind) so I put the battery on charge last night because when I checked it was flat. I had fully charged only 3 weeks earlier when I went for a hills ride which accounted for about 2-3 hours of use which in itself should not have been enough to discharge it. I took the battery from the charger this morning fitted it onto the bike and there was no charge at all not even enough to light the indicator, I put it back on the charger and watched as the Orange charge light lit up for about 10 seconds and went off again ?

So I either have a bad charger or a bad battery ? not to mention that its discharging over a couple of weeks of no use, the bike has only done 5k since Jan when I bought it I would of thought that the battery itself should not be end of life already ?

Any info, help or guidance would be appreciated, I will probably book it in at the LBS where it was purchased tomorrow but I figured I would ask to see if anyone had a similar experience.\

Thanks in advance.

[lobstermash]

Your battery is stuffed. Your charger is fine.

As batteries get used, stored (including how long it has sat on a shelf before you bought it) and charged, their internal resistance increases. Increasing internal resistance leads to greater voltage sag when under load (ie discharged to run your system), which decreases the usable capacity of the battery (ie the voltage sags below the system's required operational voltage range much faster). When you stick it on the charger, it puts back the electrons you used until you reach the target voltage.

[sil3nt]

Thanks for that, I called my LBS and I will drop my bike in there tomorrow. They are going to check the battery and the charger for me over the weekend, he did mention though that this is the first one he has had with a dramatically reduced lifespan, another mate of mine has had no issue and his bike was purchased almost 6 months before mine.