[TriLUG] OT: battery charger voltages - using 18V charger on 16V system

[Christopher L Merrill]

Joseph Mack wrote:
> I have an IBM thinkpad with a 9 cell (nominal 10.8V) Li-ion battery.
> The charger is nominally 16.8V charger (measured 16.0V). 

Is it a standalone charger?  Or are you referring to the AC adapter?

> (Anyone know why you charge a 10.8V battery with a 16V charger?
> Surely the internal impedance of the charger can't be that high.)

If the answer to the above is the AC adapter, then what makes you
think that the battery is being charged at 16V?  Have you measured
it AT the battery terminals during charging?  I had a Presario
notebook that had a separate (internal) voltage regulator for the
battery charging circuitry. I assume this dropped the voltage down
to  whatever was correct for the battery.  I could be wrong, though.

C


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