Quote:
Originally Posted by Just go Play
The spec sheet that I have for Neu 1515 motors shows the 1Y rated at 110 max amps with an internal resistance of .006 while the 1.5Y is rated 70 max amps and .011 internal resistance. This equates to the 1.5Y having 1.83 times the resistance of the 1Y.
Based on the spec sheet the 1.5Y would have a power loss of 53.9 and the 1Y 72.6. While they are close the 1.5Y appears to be noticeably more efficient. Like I mentioned it is entirely possible that there are other considerations that make this not as simple as I think it is.[/COLOR]
Based on user experience this sounds right but I cannot find any reliable documentation that proves it. (for that matter who has 6000mAh cells available today?) The discharge graphs proved by many pack builders seem rather questionable if there are any available at all. Whats worse is that there does not seem to be any standards when it comes to testing or rating lipo cells from one brand to another. Could you point me to any reliable data on cell discharge rates that confirms this claim?
I really don't think that this is a valid argument. Both motors are capable of creating almost the same amount of power at simular RPM's. I also don't think that anyone can reasonably argue that low voltage high current is more efficient than high voltage low current setups. If this was the case then everyone would be building rc's with ultra high kv motors to run on 7.4v packs right?
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To answer your questions:
1. From those specs it looks like the the 1.5y isn't ideally 1.5 turns in comparison to the 1y. An ideal 1.5 turn would have wire that is 1.5 times the length has a 1 turn and 2/3 the cross sectional area (to fit in the same space), making it have 1.5 x 1.5 = 2.25 times the resistance and 2/3 the kv. That said, the motors cannot be considered "equivalent" with the 1y on 4s and the 1.5y on 6s.
2.
http://www.enerland.com/product/p1.php?num1=1&num2=4 These are considered to be some of the best cells in the industry. It's quite obvious that bigger cells hold their voltage better under a load than smaller cells when you look at the discharge curves. True that there seem to be no 6000 cells available, but that has nothing to do with my point. I was comparing 4000 mah cells to 6000 mah cells for the sake of simplicity.
3. I never said that lower voltage was more efficient than high voltage. In fact i never even said they were equal in reality. I said that a neu 1y on 4s is efficient enough for it not be necessary to use a slower motor on 6s. So how can a 4s setup that a.) that still runs cool and b.) has all the power you need, be inadaquate?