I am sorry but how do i know that.. It is the original Nokia charger that's for sure. And oh now it's 82%. And it's been like 3 hours since it was 77%. Do you think it will go to 100%? Also, is the device worth keeping? I have a 950XL as well.. But on dark gloomy days, I wanted to use my flashy Yellow 1520 to brighten the day...
Ah, that's good. Most likely what you find, is if you leave it overnight it'll go higher but not to 100%. Then discharge again, down to about 5-10% and repeat - the next time it should go higher. Eventually you should get to 100, and have a good battery again.
IDK how mechanically this works, but this seem to be what you do with flagging batteries (I've some personal experience)
Lithium batteries are weird little creatures, but I think you'll be able to breath life into it.
Chargers will have the amps written on them, or at least the watts (watts is amps times volts, and standard for USB 2.0 is 2 volts. So if it says 2W, its 1 amp. Hope that makes sense).
If you can find yourself a 2-2.5 amp usb 2.0 micro charger, like one usually used for a windows or android tablet, this will go much faster.
You can pick up such things from dollar stores pretty cheap. An apple ipad charger will do the trick (those are 2.5 amps). Or you might have such a thing lying around or a mate might have one.
Some phone chargers are just the old 1 amp standard. Which is normally fine for a phone, but with this battery we want it to be higher ideally, to get it as high each time, as we can in the shortest amount of time.
Amps is like the flow of water through the pipes. You can't have too many amps either (volts is the one you want exactly 5% within 2 volts for usb 2.0), it won't hurt your phone, it'll just charge quicker (which later on will be helpful anyway. I charge my little phone on 2.5 amps and it charges in no time flat)