MacBook battery: Is This Battery Dead?

[G3User]

I have a battery from an older MacBook I'm trying to use as a backup with my new MacBook. They are both white, same size, both Intel Macs. The battery certainly fits. The problem is, it shows no bars even after charging for a while. The percentage says zero and doesn't change even after 45 minutes or so. Is this battery ruined, or needs to charge all night? Or could it be that it doesn't work with this computer, even though they seem to be interchangeable?

Thanks so much, as always, for your excellent advice.

 

[ElDiabloConCaca]

If the battery is completely drained, then it's useless -- Lithium Ion batteries cannot fully discharge and come back "from the dead." How long has the battery not been used?

It somtimes takes about 4 hours to get an 80% charge out of the battery -- if the battery is really low on charge, it could need to be charged 1 to 2 hours before it even registers as having a charge.

All MacBook batteries are interchangeable, with the exception of the newest, aluminum MacBooks.