For the record, I'm running a Lenovo T420i with a 6 cell battery.

In the past I've been told that it's bad practice to run a laptop on AC
with the battery installed because it would cause reduced battery
capacity. This raises two questions. First, is it true that laptop 
batteries don't have overcharge protection, and second, how many cycles 
is a battery like mine good for?

-- 
Bob Holtzman
If you think you're getting free lunch, 
check the price of the beer.
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