I went to the apple store today because coconut battery was showing that my design capacity was at 81% and I had under 300 charge cycles. I've noticed a significant decrease in battery life and it only lasts 3-4 hours with the screen dimmed and with light use. When I went there, they ran diagnostics on it and said that there was no problem with it and it was actually at 88% capacity, When I showed the coconut battery reading, they said that it wasn't accurate as it was a third party app. is this true?