I have an old early-2008 Macbook which I'm using only occasionally (my main machine is now a mid-2012 Macbook Pro).
The old Macbook's battery, since it was a 3rd replacement, still has about 90% capacity. However, I've left it in the Macbook and haven't recharged it for several months now.
Now, when I plug it in, it doesn't charge ("Replace Now"), the light on the charger connector turns green after 2 seconds of orange; and the laptop is powered from the grid. The Battery Health Monitor app (which tells me that the capacity is still ample) tells me that the voltage of the battery is approximately 7.01 V.
Is the battery dead forever? Or is there a way to revive it?
(It's Li-Ion.)
Best Answer
The battery is dead and there's no way to revive it. It's time to replace it with a new one (get a quality battery with an 18 month warranty)
The logic board needs a minimum of 12V to operate. 7V is way under the threshold to turn on and will require the AC adapter to be plugged in.
For further details, see this post: Fully charged MacBook Air turns off when power cord removed