Noticing my case is starting to warp slightly, and the drain time for the battery is severely diminished.

I know my product model (RZ09-0281x) is outside of warranty - but other than the battery issue, it's still serving me well.

Would it be possible to get a confirmation on the "supported" battery model and specs? I know an official replacement is unlikely at this point, but I'd be happy to take on any repair/upgrade cost (and risk) myself.