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- Location: Highlands Ranch, CO
Went I looked at this a few weeks ago.
I seen they were like $15.00 each and not including shipping.
I wonder and still do, how much differeance is there from what i ran, the two 9 volts, running 18 volts, the lithuim batteries. about $8 each.
There are 1000 milliAmps in an Amp.
So 5 amps, thats impressive.
Yes, the capacitors are expensive, but its the only way to get real current. Alkaline 9 Volt batteries pull down to something like 5 Volts at 1 Amp almost immediately. See the discharge curves on http://www.powerstream.com/9V-Alkaline- ... ?nowritefs" target="_blank Lithiums are significantly better (and lighter), but their short circuit current starts at 3 Amps and drops to 1.25 Amps after about 1 minute. Their load charts are here: http://www.batterymart.com/images/u9vl-charts_lg.gif" target="_blank The fans are rated for 5 Amps and up.
Does the Farad rating have anything to do with how fast the capacitors charge up or "dump" the charge? Or is there some other measurement for the "speed" of a capacitor. I assume there would be a happy medium. Faster charging leads to faster dumping. Slow charging leads to a slow dump. The write-up on the MaxV kit states that with at least 5 seconds of charging, the fan runs for 10 seconds. Would changing the F measurement alter the charge and dump speeds?
Losi Sport battery - 7.2V 1100 mAh, 4.4 oz.
Helotes battery 7.2V 1400 mAh, 5.1 oz.
Receiver/speed control ( It is all in1 unit) maybe 5 grams
I weighed 2 Duracell 9V batteries at 3.2 oz so the Losi Sport battery might be light enough to use. It is only 1.2 oz. heavier than 2 -9 volt batteries. Has anyone tried wiring one of these batteries directly to their motor. If memory serves me a Lipo battery is 11.1V, has an insane amount of power, has a tendency to explode, and would probably burn up the Losi ESC. But maybe not for that short burst. I have a Mamba brushless motor system in one of my Mini-T's but it comes with its own speed control set up. It's very light and probably could be used in this application.
Cost - The best way to buy a Losi Mini-T is on ebay. With patience, you can usually acquire one with Nickel Metal Hydride batteries, modified motors, a battery charger and maybe chrome wheels. The wheels don't add any speed but they look cool. You now have an RC car to play with when it isn't derby time. You should be able to acquire a nice car for less than $80.00. At Derby time you can fire up your motor before the pin drops. If they won't allow you to do this it really doesn't matter. Your motor will reach top speed instantly. I like to do a "Burn Out" with my wheel driven cars to heat up the rubber. I'm allowed to do this because I own the track. It's Great Fun and the kids love it. The Mini-T has 6 channels so you can race cars against each other.
Good Luck to everyone with the Air Powered cars.