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Old Jan 15, 2013, 09:51 AM
At peace with his albatross
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United States, CA, Vacaville
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Originally Posted by davehour View Post
LOL, yes they do. Actually, I use Gens Ace 25C 6S 3300mAh batteries in my 12S T-rex 600EFL Pro heli. And if you read reviews, pilots can't tell the difference between them and the Thunder's and the other high priced packs.

Now, lets talk about real life ratings. It's hard for me to think of those 65C. 5000mAh batteries delivering 325A continuous; yeah right. Use it that way. Won't last a dime.

From my experience with Lipos, using more C's than actually needed is no good. You have a battery with more weight, and this weight will fight back your gain in punch and duration, if any.

The real key in Lipo longevity is to not over discharge it, not over charge it, and store it at the proper potential and temperature. Remember, there is a self degrading chemical reaction in Lipos, even when they are sitting. Storing them at the wrong temp and potential just advances the inevitable deterioration.

David
The thing about the high C rated batteries is that they can give more current without the voltage dropping, like when you apply a burst of throttle. I personally cant tell the difference between a Thunderpower and a Skylipo of the same C rating, but I can definitely tell the difference between a 20C and a 65C battery (of any brand name) when giving a model (boat, plane, heli, car, motorcycle, quad rototr, etc.) the "throttle punch" test.
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Old Jan 15, 2013, 10:04 AM
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Puerto Rico, Guayama, Guayama
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Originally Posted by wannabe View Post
The thing about the high C rated batteries is that they can give more current without the voltage dropping, like when you apply a burst of throttle. I personally cant tell the difference between a Thunderpower and a Skylipo of the same C rating, but I can definitely tell the difference between a 20C and a 65C battery (of any brand name) when giving a model (boat, plane, heli, car, motorcycle, quad rototr, etc.) the "throttle punch" test.
That's correct, but in the case one have what's needed, going higher won't help that much.

I've read many saying they can't feel the difference between a Gens Ace 25C vs other brand 65C, at least in 3D helis. Another thing to consider is True C rating. Many brands over rate their batteries while others underrate them; hence the non existent difference in some batteries with different C ratings.

For big difference in C ratings between some batteries, you can tell, but I don't think the difference will be that much between a good 40C and 65C battery. Or besides the punch, what else can you get? Speed:? Better handling? What about jumps, where weight is multiplied by the G's produced; then, you get almost 1kg more of dynamic weight at that moment. Again, going high C's also increase weight, and the little punch obtained is shadowed by the handling issues due to the weight increase.

What it's important is to use the practical C rating for an application. Going way more than what's needed is useless IMHO. But manufacturers know going high C's means more sales for people looking just the highest C's.

David
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Old Jan 15, 2013, 10:17 AM
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Taking for example my MM450 and the stock 3200 20C battery, it has plenty of punch and I'm not missing any of it. I believe 5000 20C would be sufficient, but there's also practical experience and the fact a higher C will last longer if a lower C is marginal for the application.
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Old Jan 15, 2013, 10:20 AM
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Originally Posted by Gaz-b View Post
Wow do they really still make cells under 40c.
Gazb,

I really doubt I'll use a 40C battery in my stock MM450 . The stock 20C gets barely warm running the bike hard on bitumen.

The stock battery has 34 cycles on it, and the IR (internal resistance) of the cells measures the same as when they were new: 3 mohms.

David
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Old Jan 15, 2013, 11:06 AM
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I go with higher c after testing different types of aircraft with data logging more c + more volts under load more volts + more watts .that's more power mate.
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Old Jan 15, 2013, 01:44 PM
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I have solved the issue of not having another bike to race against and to have two one for somebody else to drive.
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Old Jan 15, 2013, 01:47 PM
At peace with his albatross
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United States, CA, Vacaville
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Originally Posted by Gaz-b View Post
I have solved the issue of not having another bike to race against and to have two one for somebody else to drive.
You are a good man to hang around!

However you need to use proper punctuation in your text.....
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Old Jan 15, 2013, 02:00 PM
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Higher C rates do not add any extra weight to a pack. You can combine higher C rates with any capacity pack to dial in an ideal power set up. Higher C rate with lower capacity means a light weight set up equal to a low C rate high capacity pack. The amp capacity under load can be the same but the set up weight will be different.
The point is for racing and having to run only a few minutes use a high C rate low capacity pack because you dont need the extra runtime or weight necessarily. You do want the highest voltage under load for competition.
For bashing around you want high capacity for more runtime and low to mid C rates. As long as you do the math (or read the label) you want to have a pack that covers 100-120A no matter what capacity and C rate combo.
The VMX/MM450 runs great on a cheap pack and really has punch with anything extra.
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Old Jan 15, 2013, 02:06 PM
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California central coast
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Originally Posted by Chris Nicastro View Post
Higher C rates do not add any extra weight to a pack. You can combine higher C rates with any capacity pack to dial in an ideal power set up. Higher C rate with lower capacity means a light weight set up equal to a low C rate high capacity pack. The amp capacity under load can be the same but the set up weight will be different.
The point is for racing and having to run only a few minutes use a high C rate low capacity pack because you dont need the extra runtime or weight necessarily. You do want the highest voltage under load for competition.
For bashing around you want high capacity for more runtime and low to mid C rates. As long as you do the math (or read the label) you want to have a pack that covers 100-120A no matter what capacity and C rate combo.
The VMX/MM450 runs great on a cheap pack and really has punch with anything extra.
Good info thanks Chris. Say, can I ask you a random question only you might know for the rear shock spring...I know nothing about springs, but do you have any info on its rating or strength so if we want to look at other brand springs we are not shopping in the dark? Glad you keep in touch around here. Hope your staying warm out there!
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Old Jan 15, 2013, 03:36 PM
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Originally Posted by Teamsherman View Post
Nice vids mate!!

Is that your backyard or property mate? id love to have that bush surrounding my place!!!!
Thanks Alan. Yes that's the backyard. Room for a bit of fun lol .
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Old Jan 15, 2013, 03:38 PM
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Cool mate, you look like you are enjoying a bit of a change from the dust, your silver rims look good.
Loving it thanks mate, be great all year round no dust. I like the look of the rims way better than black.
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Old Jan 15, 2013, 03:38 PM
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Originally Posted by davehour View Post
Hey Chris,

Do you use a head cam to record the videos?

David
Hi David yes I use a camera on my head.
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Old Jan 15, 2013, 03:42 PM
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Originally Posted by davehour View Post
LOL, yes they do. Actually, I use Gens Ace 25C 6S 3300mAh batteries in my 12S T-rex 600EFL Pro heli. And if you read reviews, pilots can't tell the difference between them and the Thunder's and the other high priced packs.

Now, lets talk about real life ratings. It's hard for me to think of those 65C. 5000mAh batteries delivering 325A continuous; yeah right. Use it that way. Won't last a dime.

From my experience with Lipos, using more C's than actually needed is no good. You have a battery with more weight, and this weight will fight back your gain in punch and duration, if any.

The real key in Lipo longevity is to not over discharge it, not over charge it, and store it at the proper potential and temperature. Remember, there is a self degrading chemical reaction in Lipos, even when they are sitting. Storing them at the wrong temp and potential just advances the inevitable deterioration.

David
Hi David I use between 30c and 40c batteries and they give me all the power I want. The vids are using these batteries.
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Old Jan 15, 2013, 03:44 PM
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Originally Posted by Chris Nicastro View Post
The VMX/MM450 runs great on a cheap pack and really has punch with anything extra.
All in all, that's what I've discovered. The bike runs well even with the stock 3200 20C pack.
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Old Jan 15, 2013, 03:46 PM
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Originally Posted by chktm View Post
Hi David I use between 30c and 40c batteries and they give me all the power I want. The vids are using these batteries.
Great Chris. I'll then get the 25C one.

BTW, do you run the batteries down to cutoff, or stop at the 20% mark which is about 3.75V per cell?

Are the batteries with connectors fine for offroad use? I mean the ones that have their wires connected to the case by means of connectors.

Thanks you very much,

David
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