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Test your batteries on your computer.

Test your batteries on your computer.

Old 10-01-2004, 03:58 AM
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Default Test your batteries on your computer.

Has anyone used this product:
http://www.westmountainradio.com/CBA.htm

Seeme like a cheap alternative to testing batteries.
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Old 10-01-2004, 05:24 AM
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There is a review of that product in this months Xtreme R/C mag.
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Old 10-01-2004, 06:22 AM
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It's cheaper than buying a $350 charger and doing it.
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Old 10-01-2004, 06:23 AM
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Yup, I know they seemed to like it....although it will not discharge at the rate advertised. It still should give you an idea of the condition of your batteries.

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Old 10-01-2004, 12:10 PM
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What's the point of discharging pack information?

It won't tell you what the individual cells are doing, if you want to know any real info other than pack capacity and pack voltage which you can get a pretty good idea about on the track anyway this does not provide it.

If you have a bad cell and need to know which one it is, you haven't learned anything usefull.
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Old 10-01-2004, 12:50 PM
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Knowing the discharge curve of ours packs is not bad.
They advertise 40A or 150W, whichever is higher!
So this device will discharge a 7,2V at 20,8A.
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Old 10-13-2004, 04:31 PM
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You can do the same thing with a $50 dollar volt-meter from radioshack and a light-bulb discharger. The only downside is that the amp draw from the light bulbs aren't constant - but should work for comparing packs.

Radioshack has a few models with the capability to interface with a computer and they include the software.
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Old 10-13-2004, 05:26 PM
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Steve You are correct, you could use a meter and light bulbs. The bulbs do draw a constant current but as the pack discharges it takes more of a load to keep the amp draw constant. The light bulbs are not totally a bad thing because if you think about it a motor acts exactly like the light bulbs. The motor like the light bulbs has no way of increasing the amp draw as the pack discharges.

Dave
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Old 10-14-2004, 09:22 AM
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Just pic up a 16x9 v5, you can get them cheap. Discharge the pack at 20amps and just write down the voltage at the desired times. I've done it in the past and it works fine, as long as you don't mind staring at the charger for a few minutes. Plus you get charging and cycling options with it.....
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Old 10-14-2004, 10:01 AM
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Looks pretty cool. If I had more of a digital background I would build that into my discharger that I am building. Unfortunately I am not really a programmer either.
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Old 10-14-2004, 10:06 AM
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Originally posted by crimson eagle
What's the point of discharging pack information?

It won't tell you what the individual cells are doing, if you want to know any real info other than pack capacity and pack voltage which you can get a pretty good idea about on the track anyway this does not provide it.

If you have a bad cell and need to know which one it is, you haven't learned anything usefull.
You will know which of your packs are the best. You will know the runtime of your packs before you run it so you will know how to gear it..... Need I go on?
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Old 10-15-2004, 06:39 PM
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Default Voltmeter use

You can do the same thing with a $50 dollar volt-meter from radioshack and a light-bulb discharger
-Steve R

I do not have a problem measuring voltages with my little digital voltmeter.
But I have not figure a safe way of checking higher amp rates, I think 3 amps would burn out my meter. Is there some trick to measuring higher amp amounts?

I would think almost all the readings you get from an expensive charger, you should be able to do with the average low end Voltmeter.
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Old 10-15-2004, 06:50 PM
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Chill Will,

This is something you already know. A track is the best place to get an idea of which cells are best. Do they last more than long enough? Do they have good speed for the entire race? Bad packs don't do very well on the track and won't do very well on this device. But you can test the pack on the track without buying any new equipment. Now if you can analyse the data from each cell on a pack which you know is bad, then you can replace it or convert to a 4 cell pack or whatever. This is when you will get info you don't already know.

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Old 10-15-2004, 06:54 PM
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Imjonah,

Most meters can go to 10amps. If you want to do more you can buy a shunt off ebay for pretty cheap. A 50amp shunt is more than enough. Just measure the resistance accross the shunt under discharge and convert to amps. This will tell you your discharge amps. You can measure voltage at any discharge rate, you won't hurt the meter.

Dusty.
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