| archer9234 said: Use that empty space in a iPad to improve the battery. Stop packing the same small crap battery that lasts 4 hours. |
If you're only getting 4 hours out of your iPad, you should return it for another one. It's defective.
And there isn't any empty space in the current iPads that isn't filled with battery. 3rd gen iPad was 7% bigger than the iPad 2, but packed in 70% more battery.

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