Higher voltage and efficiency

[crazyjr]

Originally Posted by asheck

Sure, simple :)
Brian, can I have your opinion on how much the overall system efficiency would change going from a 1000 watt setup on 3s to a 1000 watt setup on 6s, using a MMP 1512 type combo, adjusting kv for max motor efficiency. Also dropping the Mah of the battery in half.


Ha ha, crazy, I'm running one of those Quark 80's now. I have it in a Slash 2x with Jato arms. I run it with a Tacon 3930kv 3650 motor on a 2s 6000mah. Temps will normally be around 30-40 above ambient. This is a graph of it running 40mph, with Badland 30 series. I kill the battery in around 20 minutes. It's probably pretty close to the same weight as the above Pede.

So here's what I don't get, I'm running 20 minutes on 6000mah going 40mph, you say

So according to this claim, if I was to run the same time , even at my lower speed, I would need 3 packs , or 18000mah on 2s the equivilant to a 9000mah 4s, or around 2.5 times more battery.

These are the kind of claims that confuse me. I just can't see where that kind of difference can really be had. I could see maybe the extra 5mph coming from the added efficiency of the voltage, but 5 mph and 2.5 times the runtime....

I am comparing my Mamba Max 4600 CM36 verses a 1200kv Lehner basic XL

You need a noticable jump in voltage for the efficiency to really show, I did the 2s to 3s/same motor and saw not too much improvement. When i doubled and 2.5 times the voltage and lowered the kv, i saw mediate gains in efficiency and lower temps. I also gained by going bigger in motor, The Lehner XL basic motor was considered a MT motor when brushless rc was sorting itself out. At 1200kv, it's only pushing 22,000 RPM's on 5s lipo. I know that the motor is capable of 60,000 rpm, but why do you need ti run it like that? Runs fine and cool and like a 4 stroke nitro, torque out the wazoo