I have a Twinhead Durabook S14y battery that needs refill. The details are as follows:-

PN: 23+050272+11
Model: R14KT1
11.1V 4.4Ah

Last time I checked it was rated only about 1.1Ah - a loss of about 75% of its original rating.

On normal use (no blue tooth no wifi) , it could last about 10-15 minutes. Is it possible to upgrade it to 9 cells?

I am nearby Idaman Plaza, which is pretty close to your danau kota location. Where can I drop you the battery?