Try this:
Above is my current battery, 8hr playing with 30 brightness (40 is minimum default)
My original battery only lasts for 4hr. It takes >4hr to charge (3h with original)
If there 3 are new, i think it will be much better (OMG i got 2 old BT50 for only 1$
)
Fell free to ask and sorry if my English f... your eye