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Re: Batteries




On Fri, 1 May 1998 13:56:23 -0500 (CDT) "Brian K. Michalk"
<michalk@awpi.com> writes:
>
>AH is a total measure of how much energy the battery contains.
>Suppose we had a perfect 10AH battery.  This means that the
>battery will be able to supply 1 amp of current for ten hours.
>It should also be able to provide 10 amps of current for one hour.
>In the real world it doesn't work that way.  If you draw too
>much current you use a lot of the energy to things like heat
>which causes the battery to lose efficiency.  The less current
>you demand, the better the performance.
>
>All of the above really applies to deep cycle and disposable
>batteries.  Rechargeable batteries are a little different.
>Car batteries are usually rated in CCA, or cold cranking
>amps.  The reason why they are not rated in AH is because they
>are designed to be drained by 1% to 10% of their total
>capacity.  Constantly deep cycling an auto battery will 
>cause failure of the thin lead plates.  I'm not a chemist,
>but I imagine that the deposition of lead from lead sulfate
>is not uniform, eventually eating holes in the thin plates.
>
>Basically AH is a measure of total energy capacity.
>CCA is how many amps you can draw before you have used
>up 1% to 10% of your batteries' capacity.
>
>-- 
>Brian Michalk  <http://www.awpi.com/michalk>
>Life is what you make of it ... never wish you had done something.
>Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
>musician, home-brewer, entrepenuer and SINGLE!
>
Well stated, Brian! BTW, Al (et al), the series 70 battery Velocity
recommends is, I believe,33 lbs. It has been a while since I weighed one.
 It helps make up for that extra nose weight for single pilot flying!

Martin

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