There's been increasing concern over the last few days regarding the phones' battery performance. The chips were being sourced from the two diffrent companies. The one with the TSMC processor has a longer battery life. Apple has published a statemant, saying the battery spawn has little diffrencies in both variants of the phone.
With the iPhone 6S there will be a diffrent story. Apple is using A9 chip, which will give us "highest standards of great battery life", as Apple says.
