[MichF]

TL;DR:
PRS-T1 shuts down at 70% charge. What to do?

Hi there!

I have this problem with my PRS-T1:
Discharging seems ok at first, slowly going down from 100%
after fully charged. But shortly after it hits 70% (after maybe
2 days of heavy use) the device suddenly decides that the battery
is empty and shuts down. I even cannot turn it on again, unless
I connect the charger. When I check the battery state immediately
after this, it tells me that it's still at 70%.

My PRS-T1 is fairly new. This problem is present when the
device is rooted as well as when the original firmware is restored
(to the latest firmware version). WIFI is switched off.
I also wiped batterystats.bin, without any effect.
I am using a wall charger.

Any idea what I could try to regain the full battery capacity?
Or which mechanism android uses to sense 'battery empty'
besides the charge percentage?
Is it possible to buy a replacement battery somewhere on the net?

Thanks!
MichF