Is This Battery Dead?

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 i believe. The battery certainly fits. The problem is, it shows no bars even afte charging for a while. The percentage says zero and doesn't change even after 45 minutes or so. Is this battery just 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 for any help.

note: I chose wrong prefix. This is a MacBook, both of them. One is just a little older. The batteries seem very similar. Thanks.

look at the voltage and amperage on the bottom. I know for a fact the MB and MB Air are 2 different voltages. my MB is 10.8V. but just because it fits doesnt mean it will have enough/too much power to run the computer.

worst case, take it into apple. they will test the battery charge for free.

Good God, i don't know how it got to say MacBook Air. It's a white MacBook, just like the other! The batteries seem identical. They should be compatible, i would think? Thanks.

Try downloading coconutBattery. It might shed some light on it?