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Mar 01, 2004, 03:20 PM
Visitor from Reality
Mark - idle thought on batteries. Go for more volts rather than amps any day. A decent ferrite will go on for ages if you don't beat up on the brushes and high amps will do them in much faster than higher volts. The venerable Mag Mayhem is a fine example - 25A and it's happy for ages, up that to 30 and you're on borrowed time, especially if you have to run it for a long time. Yet folk have run MMs on 10 cells with no ill effects.

Math? 10 cells, say 10V for simple numbers, X 25A = 250W. To get that from 7 cells takes 35A. You're starting to depress the battery volts too, so you'll get even less, plus the 35A will soon eat those brushes.

My favourite math here is adding two CP2400 to a 3lb model carrying 8 of them already. Weight goes up around 8.5%, while power, given you mess with the prop and/or gearing some to maintain the amps, goes up 25%.

Not a bad deal ...?

CP1700 aren't too bad - the 1300s are pretty depressive so I've heard - but the CP2400 offer good bang for the dollarpound - smart move there.

D
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Mar 01, 2004, 04:43 PM
Ay up it's warped
mtbrider's Avatar
Dereck, I really must measure my Amps but at the moment I will have to wait for the weather to warm up, or borrow a car battery to trickle charge the new batteries indoors (10 cells). Missed some nice but cold flying today as I had my rest day concelled. Not impressed. Ps I have not forgoten your request for a photo of my cub for Traplet.


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