RE: (ET) Batteries and lighting

["Dave & Deb" <daveb drizzle com>]

Yeah I wondered about the "real life" meaning of this draw down test and
tried to ask but there was a lot of folks and distraction going on.  
since Dave Cloud's focus is racing, drag and endurance, I would guess it
has more meaning/application to him than it does to us with our etraks...

However I don't think a car battery is ever meant to be drawn down to
10volts is it?

Dave

> At 07:30 AM 3/12/05 -0800, Dave & Deb wrote:
>>Here's the battery dran down results I mentioned earlier.  I see I lied,
>>just a little, about the car battery outperforming all the optimas but
>>still it showed surprising capacity considering the number of cycles on
>>it.
>>
>>Here are the results I recorded from our drain test demonstration last
>> night:
>>
>>41.2lb Orbital XCD34
>>forty some seconds to 9.5V
>>0:44 to 9.5V @ 400A
>
> <snip>
>
> That's more of a test of cranking capacity than run capacity.  It's not
> surprising the car battery showed well, that's the kind of use they are
> optimized for.  Deep Discharge batteries are optimized for long runtimes
> but at lower currents.  Optimized being a somewhat fuzzy term in this
> case.
>
> 400A is a reasonably substantial battery load even for an industrial
> forklift.  Peak motor (not battery currents) during acceleration can run
> 600-1000A (it's been a while since I measured but battery draw would be
> well below that) and during run the draw can drop to 30 to 75A depending
> on
> the vehicle.
>
> Robert
>
> " 'Freedom' has no meaning of itself.  There are always
> restrictions,           http://www.aeolusdevelopment.com/
> be they legal, genetic, or physical.  If you don't believe me, try
> to
> chew a radio signal. "
>
>                          Kelvin Throop, III
>
>
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