Higher voltage and efficiency

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

I could run 60+ minutes running a 4s 3700 mah 20C flightpower lipo. Not sure exactly what the gearing was, but it did 45 on radar runs with masher 2k tires. Temps always at around air temps

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....

[sikeston34m]

Shore! It's simple! LOL

[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

[_paralyzed_]

Originally Posted by asheck

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....

Too many variables to deduce anything. Is the overall query based on, "why all the hype over hv?" when your lv setups work fine?

IMO low voltage setups only work as well as they do now because all of the esc manufacturers have had time to work the bugs out. A simple oversight in gearing or maintenance can highlight the shortcomings in these setups and make them go poof.

Whether they are really more efficient or not in terms of usable mah, I believe, in the end will be negligible. However, the power flowing is used more efficiently as evidenced by component temperatures. The peace of mind of having cool components is enough reason for me to go hv. Ambient temp is way better than, "within acceptable temp range".

[sikeston34m]

Originally Posted by _paralyzed_

Too many variables to deduce anything. Is the overall query based on, "why all the hype over hv?" when your lv setups work fine?

IMO low voltage setups only work as well as they do now because all of the esc manufacturers have had time to work the bugs out. A simple oversight in gearing or maintenance can highlight the shortcomings in these setups and make them go poof.

Whether they are really more efficient or not in terms of usable mah, I believe, in the end will be negligible. However, the power flowing is used more efficiently as evidenced by component temperatures. The peace of mind of having cool components is enough reason for me to go hv. Ambient temp is way better than, "within acceptable temp range".

VERY Well Said Harold!

I aggree.