Orion 3600mAh Race Spec LiPo
#47
Tech Elite
iTrader: (41)
Get 'em while they're cheap... This is a pretty good deal, right?
http://www.speedtechrc.com/store/ebp...id=516&id=6297
http://www.speedtechrc.com/store/ebp...id=516&id=6297
#48
I think thast about $10 cheaper than normal.
#49
Tech Master
iTrader: (16)
I'm curious how much the C rating matters when you're only loading the battery at 5C or 10C or whatever. What I mean, is, does it matter more to mod racers than stock, since they put the batteries under more load? Or, does a higher C rating mean the batteries will hold more voltage under all loads, including the smaller ones. It's not clear to what extent, if any, it really means to the layman that's just running them with slow motors in club races.
I've heard it said before that C is mostly a marketing term, and is way too ambiguous (especially between different manufacturers) to really mean anything. I wish we had a way to test LiPo that could really tell the story about how the cells will react on the track in different styles of racing. I'm not convinced the standard 35A discharge like we use with NiMH is the best way.
I've heard it said before that C is mostly a marketing term, and is way too ambiguous (especially between different manufacturers) to really mean anything. I wish we had a way to test LiPo that could really tell the story about how the cells will react on the track in different styles of racing. I'm not convinced the standard 35A discharge like we use with NiMH is the best way.
Without the C-rating you would not know how much amperage a battery could provide. Known amperage can be important when running modified motors.
For Stock Racing - 27T or 13.5 BL, a 3200 only uses about 1/2 a charge for a 5-min race, so the amperage draw is obviously low.
The new 3600 is probably a newer type of cell as someone else stated, or it was designed to meet the needs of modified motors, as it provides more current than the 4800 batt, while the 3200 and 4800 provide close to the same, just different run times.
#50
In context, though...if the system only flows 10 amps,it only flows 10 amps...it doesn't matter if the battery can flow 90. It may be slightly (SLIGHTLY) better after some time, but if it's a high resistance load, the "maximum" capacity of the battery really doesn't matter much.
So you won't flow 10 amps if resistance is higher internally in the battery. Instead of producing current it will be used as heat instead. Remember, the driving force (ability to deliver punch) is determined by the battery's Volts under load. That is where IR comes in... lower IR = higher average V under a given load (say 10A). Said another way, the motor can't PULL what the battery can't PUSH.
Try some old NiMH2 batteries (say Sanyo 3000) with about 100 internal resistance per pack instead of 10. The old batteries will deliver an average voltage about 1 V lower at even a modest load like 10 amps. By contrast a new pack in good shape will deliver 7.5 V under modest load.
Take the same old pack and run your 4.5 brushless on it. The batteries will get so hot in very short time they melt the plastic. Performance is lousy, no punch, lower top speed, in short, they perform like a 4 cell pack.
The same thing happens to a lesser extent when you run a lower C rated cell of the same capacity. Punch will be less.
If what you said was true, then you could say, "the speed limit is 55. Why buy a Ferrari, when I can buy a YUGO, they both only have to go 55 mph". While it is true both will let you run the speed limit, one definitely has more "punch" getting up to speed. However the case of batteries the higher C rating should also give slightly higher top speed.
Remember that the starting current from zero to 10,000 or 20,000 rpm in a heavily loaded motor (on starting line grid) is much higher than the average. So the amp draw is really quite high... which is why a very low IR battery will have tremendous "punch" off the line and out of the corners. If my thinking is correct, then a 25C should have less voltage drop-off, less internal resistance, and therefore more punch and a little more top speed capability than a 20c cell.
The one thing I'm still wondering about is whether there is more to the "C" rating than internal resistance... hoping somebody from Peak/Orion can tell us ???
#51
Tech Elite
iTrader: (41)
C'mon now...LOL...I have at least a handshake relationship with Mr. Ohm and his law.
I know that in the RC world EVERYTHING is important and EVERYTHING matters greatly...but really...if you think a stock motor from a dead start will tax even a lowly 15C pack...then I can begin to subscribe to your beliefs. I don't think it will though.
I never said it wouldn't be any better for anything, I said that for most people running stock or 19T stuff...or off-road...there's no way you could objectively tell the difference if every other factor is held the same.
Onroad mod...who knows? More likely...but I don't run that and I don't foresee myself running that in this lifetime. It's a fast crowd around here.
I know that in the RC world EVERYTHING is important and EVERYTHING matters greatly...but really...if you think a stock motor from a dead start will tax even a lowly 15C pack...then I can begin to subscribe to your beliefs. I don't think it will though.
I never said it wouldn't be any better for anything, I said that for most people running stock or 19T stuff...or off-road...there's no way you could objectively tell the difference if every other factor is held the same.
Onroad mod...who knows? More likely...but I don't run that and I don't foresee myself running that in this lifetime. It's a fast crowd around here.
If what you said was true, then you could say, "the speed limit is 55. Why buy a Ferrari, when I can buy a YUGO, they both only have to go 55 mph". While it is true both will let you run the speed limit, one definitely has more "punch" getting up to speed. However the case of batteries the higher C rating should also give slightly higher top speed.
The one thing I'm still wondering about is whether there is more to the "C" rating than internal resistance... hoping somebody from Peak/Orion can tell us ???
The one thing I'm still wondering about is whether there is more to the "C" rating than internal resistance... hoping somebody from Peak/Orion can tell us ???
#52
C'mon now...LOL...I have at least a handshake relationship with Mr. Ohm and his law.
I know that in the RC world EVERYTHING is important and EVERYTHING matters greatly...but really...if you think a stock motor from a dead start will tax even a lowly 15C pack...then I can begin to subscribe to your beliefs. I don't think it will though.
I never said it wouldn't be any better for anything, I said that for most people running stock or 19T stuff...or off-road...there's no way you could objectively tell the difference if every other factor is held the same.
Onroad mod...who knows? More likely...but I don't run that and I don't foresee myself running that in this lifetime. It's a fast crowd around here.
I know that in the RC world EVERYTHING is important and EVERYTHING matters greatly...but really...if you think a stock motor from a dead start will tax even a lowly 15C pack...then I can begin to subscribe to your beliefs. I don't think it will though.
I never said it wouldn't be any better for anything, I said that for most people running stock or 19T stuff...or off-road...there's no way you could objectively tell the difference if every other factor is held the same.
Onroad mod...who knows? More likely...but I don't run that and I don't foresee myself running that in this lifetime. It's a fast crowd around here.
Sorry, didn't mean to offend re: ohm's law, not everyone knows it. I make the opposite mistake too often, assuming everyone is an engineer my wife in particular.
I agree it's not a major difference, but I think it will be palable when you drive. The reason I say this is, I can feel the difference in older cells with high IR vs newer ones with low IR.
But, without data, this debate can go on forever. Until someone tests this, I'll give up for now !
Cheers,
Mike
#54
Tech Adept
iTrader: (9)
Looks like these should be out before Christmas. Tower just showed up a listing for them.
http://www3.towerhobbies.com/cgi-bin...?&I=LXTMY9&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXTMY9&P=7
#55