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Art, I'll guess it at about 25 amps on the highest pitch setting. The
tester will be a long haul since the wattage at that voatge and
resistance is too small relative to the battery capacity. You could put
two of them in series and get a great test on both at the same time -
they should go 120 minutes like that, and you can put the meter on each
one to see how they are doing.


Paltz, Art wrote:
> 
> Thanks George.  Great explanation!
> 
> Looks like I have to start ordering some components and test out my battery
> over the winter.
> 
> Anyone want to compare draw times when the tester is completed?  I'd like to
> know how the draw time with 1.5 Ohms of resistance compares to real life for
> a Dacor/Apollo.  Unless someone knows the draw of the Dacor motor on it's 3
> settings?  Naturally averaged with the typical stokified gear setup.....
> :-)  Anyone from a shop know the typical draw of the motor, maybe someone
> who sells them?
> 
> Thanks again George!
> Art.
> 
>                 -----Original Message-----
>                 From:   kirvine@sa*.ne* [mailto:kirvine@sa*.ne*]
>                 Sent:   Monday, November 22, 1999 3:40 PM
>                 To:     Paltz, Art
>                 Cc:     techdiver@aquanaut.com
>                 Subject:        Re: Question about the battery tester....
> 
>                 That is my battery tester you are looking at. It is simply
> two 300 watt
>                 3 ohm resistors in parrallel giving 1.5 ohms of resistance .
> The voltage
>                 is not an issue. If you burn a 12 volt battery it is still
> subject to
>                 V=IR, and you merely time how long that "R" goes for and
> compare it to
>                 the curve supplied with the batteries.
> 
>                 We chose that combination of resistors to match the draw of
> a DV100
>                 scooter motor. The new motors that I make draw 2 amps less
> for the same
>                 thrust, and peak much lower. This test gives us a "worst
> case" burn for
>                 our scooters, which actually floats with drag, which of
> course the DIR
>                 system minimizes.
> 
>                 In your case, as you said, the objective is to just see how
> the battery
>                 compares to its rating.
> 
>                 For 12 volt light battery testing, the array happens to
> mimick a 100
>                 watt halogen bulb time-wise, and if you just use one of the
> resistors (
>                 there is a disconnnect bettween them in my setup), you will
> get the 50
>                 watt light time or the Mako motor time. Howver, why do the
> long test
>                 when you can factor the times using the discharge curve of
> the battery.
> 
>                 If you really want to roll on the floor laughing, look at
> how the usdct
>                 tested theirs or how the other guys who make them test
> theirs. I came up
>                 with these numbers based on dynamic testing using a long
> harness and
>                 remote guages so I could ride the scooter at different
> settings and gear
>                 configs. As you know, doing what I do with a scooter means I
> need to
>                 know exactly what that piece of equipment will do, and our
> tests turn
>                 out to be right on the money in real life diving.
> 
>                 I am used to claiming ignorance on issues of cave trade
> secrets, but
>                 that is not so necessary anymore. Actually , all of my stuff
> is
>                 incorporated into the GUE scooter course , and we even
> filmed me
>                 teaching part of it with Errol , but that is not available
> outside of
>                 the organizations.
> 
>                 Paltz, Art wrote:
>                 >
>                 > George,
>                 >
>                 > It's mentioned at the bottom of this web page that you're
> the EE guru.
>                 > Being that you make your scooters I'd say that makes you
> pretty much a guru.
>                 >
>                 > The battery drain/tester on
> http://www.bentleytech.com/resistor/index.html
>                 > <http://www.bentleytech.com/resistor/index.html>  says
> it's for 24V
>                 > Gavin/Mako scooters.  Can it be used to test a 12V Dacor
> if it's drained to
>                 > 10V?  I have a new battery in the scooter and I'm getting
> poor performance
>                 > from it.  This gizmo looks simple to make and test.  I
> just don't know if I
>                 > would need to modify the resistors to account for a 12V
> battery.  As you can
>                 > tell, I'm not an EE type.  I just know how to solder
> wires....
>                 >
>                 > I also assume it won't accurately mimic a Dacor motor for
> burn time but at
>                 > least I can cycle the battery and assume I've got an
> optimal charge.  Might
>                 > be fairly close though.
>                 >
>                 > Thanks,
>                 > Art.
>


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