Although this is an article on hardware, I'm going to be using software to probe it. This is from a 32GB HP Touchpad, though the 16GB should be the same, barring the difference in storage.

/proc/cpuinfo:

This is a 4-cell battery; before opening it up, I was under the impression that it was a 3-cell.

The charge controller circuit board has "LIP8198" and "1-867-277-11" markings in the silkscreen, along with a strip of Kapton tape over the top of the PCB.