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Old 03-19-2010 | 09:04 PM
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GordonFreeman
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From: Reality
Default Need to increase energy density by a factor of 4.

Originally Posted by kghills
I don't think nitro should die, I think it will die and while not this year it will in the next couple on its own. Battery types and life will evolve faster than you are saying. Auto manufactures, cell phone manufactures and power tool companies along with the government just to name a few are pouring much money and research into this. You say look how fast brushless took off. Look at speed controls now. Would you have predicted a year ago where ESCs would be right now? Look at the new Thunder Power and MaxAmps lipos. Their ratings have about doubled in the short time I have been involved in the hobby. I think it would be nieve to think there would not be a solution on the horizon, to many industries are working on it. Jason's Truggy already runs 16 min. on a 6000MaH 5s pack with the newer higher rated packs he should be over 20 min approaching 30min. You honestly don't believe in the next few years that won't double?

Keith.
Not to be argumentative with another electric lover but we can have a civil discussion:

Three years ago I was running an 8000mAh/4s battery on a 1900 kv motor and got about 30 minutes. 16 minutes on a 6000/5s seems short to me, but that's beside the point. But using your numbers you will need a 6000mah*60/16 = 22500mah/5s pack to just manage a 1 hour run time. It simply has to be that big, do the math and physics (which I've been doing for several year in 1/8 scale). Sure you could do that now with a really big (volume) and really heavy expensive battery pack. That just isn't going to fly. Guys will stay with nitro rather that having a 15lb buggy with a $1000 battery in it.

The numbers you are seeing that are increasing in battery technology are the C ratings. Eventually we could have 1,000,000 C rated batteries, but that doesn't really effect runtime. The energy density or the Mah/volume-mass is what has to increase and dramatically. The capacities (energy density) are the same as they were when LiPos came on the scene 5 years ago. Very little has changed in that aspect and that's the big thing that has to change to get 1 hour runtime. We need a paradigm shift of a factor of 4 roughly to get that kind of run time.

LiFe is not the solution as it is heavier that LiPo.

As far as brushless tech evolving, it really hasn't done much since it's inception either. The only new thing has been advanced timing. And all of this is old news if you are in industrial motor control. Somebody just got smart and copied what the big guys had been doing for decades. I hate to say there's not much more that can be done with current brushless systems, but there's not. You can only advance the timing so far before you burn up a stator as people are finding out. There will be no new magical motors made that will break the 100% efficiency barrier , so there are no huge gains to be had there since they are already in the 90% range.

The main gains will be in battery tech for sure, but I don't see it happening anytime soon. I mean you can Google a hundred different articles on new startup companies with their new Lithium-Sulphur Nano Tube Turbo battery tech, but nobody even has any prototypes yet. And they usually have some down fall too, like they run at 1000 degrees C. And how long will that take to filter down to the RC world?

Even at a club level, which could change over immediately because we only run 15-minute mains, it will take more than a few years to take hold. Within the electric realm it took brushless about 5 years for people to see the light and that was a really really tiny change (and there are still brushed motors around because of short term costs). Increasing the energy density of current batteries by a factor of 4 is going to take awhile. People want thier smoke, oil, sounds and smells. I don't think it's naive to think this way, I think it's realistic. Of course I could be wrong and I hope I am.

Let's all cross our fingers that those diLithium StarTrek batteries will come out soon!
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