That's not entirely true. Check
this mod.
Regarding battery, you cannot use classic extended battery for the i9100, as the cover will not fit (and you will lose NFC).
Read the post...Like what I said..It is not working on i9100..before you comment on something read first..if you really wanted NFC on your phone buy a NFC enabled one but as long as you are using a converted i9100, NFC is no more..revert back your phone to M250 if you wanted NFC..
You can see this on 1st post..Read it!!
Devices Confirmed Working On:
-I777
-M250k/M250s
-I9100p (after mounting system )
-i9210
-i9250
-T989
....IDK you tell me!
Devices this should work on:
i9100 = NO
i9100P = YES (it's an i9100 exactly, but with NFC. ROMs for i9100 will work, but need to be modified to show NFC settings, otherwise no NFC options will show)
i9100G = NO, it's completely different from the i9100 hardware (TI-OMAP instead of Exynos). ROMs from i9100/P don't work.
T989 (T-Mobile GS2) = YES, but it's completely different from the i9100 hardware (Snapdragon S3 instead of Exynos). ROMs from i9100/P don't work.
i777 (AT&T GS2) = YES, AOSP based roms have it but i9100 hellraised roms are missing it(due to NFC not being a feature of the i9100)
D710 (Sprint GS2) = NO
and btw..i9100p is from Orange mobile network