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Conference unifix::sailing

Title:SAILING
Notice:Please read Note 2.* before participating in this conference
Moderator:UNIFIX::BERENS
Created:Wed Jul 01 1992
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2299
Total number of notes:20724

2273.0. "NiCad Batteries" by DECC::CLAFLIN (Doug Claflin dtn 381-6355) Mon Jul 01 1996 12:15

This looks like a pretty informed article on NiCads.

The real bottom line for critical stuff, like flashlights
is that a NiCad will discharge all on its own much faster
than an Aklide.  I think the self discharge is something 
like 2% per week.  Ok for for a walkman, bad for the 
emergency flashlight.


http://vancouver-webpages.com/peter/nicad.faq

Have fun.

Doug
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2273.1Why don't they sell Alkaline handhelds?WRKSYS::SCHUMANNMon Jul 01 1996 16:5217
Personally, I've always felt that alkalines are a better battery for handheld
VHF and other low duty cycle equipment. I've only seen one alkaline handheld,
though. I think it was a low end ICOM.

The prudent mariner always carries spare alkalines on board, if only for
flashlight spares. These batteries have long shelf life, and there's very
little cost associated with keeping spares.

The cheap mariner (like me) will not have a DC charger for his handheld, nor
will he promptly replace failing nicads as they gradually get weaker near their
end of life. The result can be a radio failure at the worst possible time, 
e.g. after several minutes of emergency transmissions.

When nicads fail after 5-6 years of normal use, their $30 replacement cost
may actually be more than the cost of buying 5-6 years of alkaline batteries.

--RS
2273.2DECC::CLAFLINDoug Claflin dtn 381-6355Tue Jul 02 1996 14:1619
I think it is a perceived thing.  I have even gone so far as
to try the rechargable akalies.  I am not very impressed. 
RayoVac may stand behind them , but I have experienced
something like 25% DOA.  It is not worth the sorting.

Because so many things use NiCads (why not nickel hydrides o
or Lithiums?), I have just bought a cheap inverter to run a
battery charger.  Makes sense to me 12VDC to 110 VAC to
generate 6-18VDC depending on the charger.  Sounds lik a
winter electronics project to me.  I will sell them in the
spring;-).

Its sort of stupid.  Why is a fish finder cheaper and give
more information than a depth sounder?

Perhaps marketeers should be shot and replaced by sailors
who a strong sense of greed.

Doug
2273.3Nicads Like DischargesNWD002::RADKE_HOWed Jul 03 1996 21:5819
    I have built a nicad (constant current) charger that runs off the ships
    battery. Note that one needs to have different current settings for the
    different sized batteries. Not a big deal, it just makes charging more
    effective.
    
    Anyway, my rule of thumb is to use nicads in cycling applications (eg.
    Walkman and non essential pen lights etc.) and alklines for essential
    applications (eg. flash lights at the companionway, engine room etc.).
    
    I find that nicads last a long time if cycled frequently to the point
    of discharge. That is easy to do with a walkman and flashlights. Other
    "smarter" electronics devices (such as my laptop and cellular phone)
    shut the device off when the voltage reaches a certain low threshold, 
    thus denying the battery the opportunity of a full discharge. This in
    my experience has more to do with early battery failure than cycling.
    
    Cheers,
                                          
    	Howard