Replacement Battery for 7012?

[imagesinthewind]

So, my son killed his battery.
He did all the wrong things, keeping it plugged in for days after full charge.
Charging it when it's not in the red, etc.
Now the charge isn't holding for very long.

I opened it up, and can see how the battery is put in.
Are there replacement batteries?

I purchased him a new tablet, the 7142, but would still like to replace the battery in the old one.

Thanks
Ginny in Denver