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???
09/10/11 13:32
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#183705 - NiCd, NiMH and lead-acid not so problematic
Responding to: ???'s previous message
Erik Malund said:
create an intelligent battery charger .... i totally have no knowledge at all.

DANGER!

many battery types will explode if charged incorrectly

Erik

If it is a school project - and the teacher is at least reasonably sane - then the three types are NiCd, NiMH and lead-acid. I.e. no Li-Ion batteries involved. And none of the rechargeable "primary" batteries that exists.

For NiCd, NiMH and lead-acid, you can't normally explode the batteries with bad charging. NiCd can stand reasonably high currents by just getting warm. NiMH will age a lot if running too hot. Lead-acid cells starts to boil but should either be open or have a release valve for pressure release. The issue with all lead-acid batteries is of course that it doesn't matter if the charger is good or bad - the user must still make sure to not have sparks close to a charging non-sealed battery since hydrogen + oxygen is not a nice combination - more than one car owner have found that out by connecting the clamps directly on the poles and then remove the clamps without first removing the charge current.

When Li-Ion gets involved, it is absolutely imperative that a battery is not polarity switched. And that a too depeted battery is not charged. Or that a battery is not charged too fully. If they do not explode, they will still burn with very intense heat. And lithium does not react well to water.

List of 13 messages in thread
TopicAuthorDate
C8051 Intelligent Battery Charger            01/01/70 00:00      
   No Knowledge?            01/01/70 00:00      
   The purpose of school projects            01/01/70 00:00      
   No klowledge at all?            01/01/70 00:00      
      School project            01/01/70 00:00      
   Danger            01/01/70 00:00      
      NiCd, NiMH and lead-acid not so problematic            01/01/70 00:00      
         But still issues to consider            01/01/70 00:00      
            Normally not - they should normally split if high pressure            01/01/70 00:00      
      Danger!            01/01/70 00:00      
         More of intense fire.            01/01/70 00:00      
            New LiPo probably quite hard to explode            01/01/70 00:00      
               It is the Core            01/01/70 00:00      

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