It will not power up at all. I watched several videos prior to swapping the battery and none made mention of the correct battery connection so I didn't either. The connector on the battery has the contacts showing on both sides. I should have folded the ribbon cable over and then plugged it in rather than plugging it in flat and unfolded. When I turned it on the lightening bolt charge symbol was flashing...I thought it had a dead battery so I left it charging over night. Next morning...DEAD as a door nail. Battery still has 3.5v and I received another battery fresh out of the box, about the same voltage, still nothing when plugged it in the phone. The connector has four terminals. Keeping the common probe on the 1st and then moving to the right with the negative probe I was measuring voltage on the 2nd and 4th terminal and nothing on the 3rd, so flipping it would apply voltage to the 3rd terminal and none on the 2nd.