#4824 HIGH Update.: Should shutdown gracefully on low battery

Zarro Boogs per Child bugtracker at laptop.org
Sat Jan 12 04:46:30 EST 2008


#4824: Should shutdown gracefully on low battery
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  Reporter:  cjb                  |       Owner:  cjb     
      Type:  enhancement          |      Status:  new     
  Priority:  high                 |   Milestone:  Update.2
 Component:  power manager (OHM)  |     Version:          
Resolution:                       |    Keywords:  power   
  Verified:  0                    |    Blocking:          
 Blockedby:                       |  
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Comment(by sola):

 LiFePo batteries should not be deep cycled either. I wouldn`t suggest to
 allow any lithium go below 10% normally.

 If you want really good cycle life for the XO battery then:

 -NiMh should be deep cycled once in 1 or 2 months because it does have a
 slowly building memory effect otherwise. Not as bad as NiCd but exists
 still.

 -Even LiXX batteries should be deep cycled sometimes in order to correct
 state of charge (SOC) measurement sliding resulted by keeping the latop on
 the charger all the time.

 -Generally, there should be a battery maintenance program which executes
 every months and checks the battery usage logs (there should be such a
 thing). It decides whether the battery requires maintenance (according to
 the chemistry) and if so, then executes it. There should be some feedback
 to the user that maintenance is on.(Even if he/she plugs it in, it will
 not charge until the forced deep cycling is over.

 That said, I have never seen a battery maintenance program on any OS yet,
 even though this is the way it should work. Without periodic maintenance,
 batteries get half or worse cycles than factory specs. (for more info see
 batteryuniversity.com)

-- 
Ticket URL: <http://dev.laptop.org/ticket/4824#comment:6>
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