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Don Klipstein Don Klipstein is offline
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Default Lithium battery disappointment

In article , Jeff The Drunk wrote in part:

SNIP to here

Li-ion batteries have a max number of charge cycles regardless of how
deeply discharged they are.. They also have a finite shelf life. Don't
know the figures but you can extend the storage life of li-ion
batteries by refrigerating them. Nominally expect full capacity for 5
years from what I have read although YMMV. My battery pack in my Asus
laptop from 2004 still lasts about 1.5 hours. My Toshiba laptop from
2002 is acting up. Sometimes I run it after the charge indicator says
complete and it will last 5 minutes. Sometimes it will go an hour. I
think it is a charging issue with the laptop since the battery pack
remains cold to the touch while charging. But what is puzzling is the
battery will charge for a couple hours until the completion is
indicated by an LED regardless if the battery actually charges or not.


I have familiarity with charging ICs for Li-ion batteries, to extent of
having laid out and assembled working circuit boards. The IC that I used
times out after 3 hours, even if charge is incomplete or the IC fails to
make the circuit deliver full charging current (or any) due to temperature
or battery condition or connector issues. However, if after the 3 hour
time-out the IC that I used determines that the battery stands to be
recharged, it restarts attempted charging for another 3 hours.

Some other circuits may have a time limit without automatic restart
after the time limit. I am familiar with a Ni-MH charging IC that stops
at 4 hours even if the battery is not fully charged, and only restarts if
the charger is turned off and back on.

- Don Klipstein )