question on lithium ion batteries

[dewar@GNAT.CS.NYU.EDU (Robert Dewar)]

I asked this before, and someone answered that Li-ion batteries were
ideal, but did not actually answer the question.

My question is: does it do any harm to leave a Li-ion battery in place,
charging in the TP. I notice that the TP keeps it at 100% charge all
the time (instead of doing the down to 90% game it playes with NiCad's)