Well, you can count me as an exclusive user of this battery since the day I got it and everything is good. XDA, has a ton of replies about it and only praises. Here is a deal where I think a lot of the people get confused. DO NOT take anybody's else screen on or days on numbers too close to your heart. It's an irrelevant benchmark because everybody has a different setup and different use. The fact is that OEM battery is 3100 mAh (confirmed and verified), extended batteries from various vendors are 6200-6400 mAh (confirmed and verified), and this battery is 9300 mAh (confirmed and verified). So you are getting double capacity with extended battery and triple capacity with ZL battery. If you can swear on your life that you have exactly the same setup and identical use, and running the same apps with a same config, and you do not see an improvement - perhaps something is wrong with a battery. You have 3x stock size/capacity batteries fused together, could be possible that some connection broke off or something. The test I ran to get 20hr screen time was not realistic phone use. It was Nova Battery Tester program with a cpu stress test which exercises faster battery drain while timing it. That test takes all the variable out of equation by turning your 4G connection off, turning brightness to max level, and disabling other background processes. That test can also estimate mAh reading, and i found it to be for ZL approximately 3x the capacity of stock battery. It's not an accurate measurement, but relative measurement. So if you run that test with your stock battery or extended double capacity battery, and then with ZL and you don't see 3x or 1.5x improvement - something is wrong with your ZL battery and it has to be replaced under warranty.