Extended battery still showing 1750mAh

[Guest caballeropl]

Hi folks. I purchased the extended battery for my GNex (2000mAh official samsung) and after changing it and charging my battery app (DU battery) is still showing 1750mAh capacity after full 100% charge. I run stock 4.3 JB. Any ideas? Should I just igone it or does my phone think I still have the old battery in and can't charge it up to it's full 2000mAh?