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Old 19-06-2009
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Quote:
Originally Posted by JJ The Boat Wizzard View Post
Quote "Technically it is not the current draw which kills a pack, its the relationship between current draw voltage drop and heat. If you draw too much current, the voltage will drop off, below 3v per cell, and damage the pack, end of story.

To put this into real life terms, in a particular type of RC Glider, they draw on average 75-100C (yes you heard me correct there!) from their packs, for a maximum of 3 to 4 seconds. This is way over any packs "burst" rating, but as it only happens for a short period of time, the packs do not go below 3v per cell, the result, they do not kill their packs at the rate you would image them to! If they flew for more than 3 or 4 seconds at this rate then yes, the packs would get damaged. " End Quote


!That is all we have been trying to say!
Thanks for confirming that


John
but there is no way the original posters gear wil draw 75-100c in a car, so your still giving wrong info
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  #22  
Old 19-06-2009
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So I've been thinking about this a little more...and looked at some numbers for things with regards to matching your motor and esc to your battery, your esc should most likely be over specced according to your motor, and battery.

For example, the Novak GTB is rated at 540A per phase, brushless is a 3 phase motor so that's over 1500A ??? (that is probably wrong but you get my point!) that the esc can safely operate with.

Thankfully brushless motors run way below this level, even Novaks fastest motor, the 3.5t Ballistic motor has a power rating of 620W which, using a simple calc (P=VxI), means that it will on average draw around 85A on a 7.4v battery, in very simple terms.

I guess what this means, the element of the system that provides the control should ideally be rated to work reliably with currents well above what the energy source and the load are capable of generating, this means that it can safely and efficiently be in control of both!

Seems logical to me?
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  #23  
Old 19-06-2009
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Quote:
Originally Posted by mark christopher View Post


but there is no way the original posters gear wil draw 75-100c in a car, so your still giving wrong info
NO i never said it would in a 10th car i said it could if you geared it wrong with a 'silly motor' so your giving wrong advice by saying ignor my post as lipos will never puff! and why do you have to argue with everything i say in every post clown im sick of arguing with you now if you want to try it plug a 2500 10C battery off of ebay into your 3turn setup and see what happens
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  #24  
Old 19-06-2009
leeleefocus leeleefocus is offline
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Thank you Trakpower. Nice post from someone who people will listen to.
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  #25  
Old 19-06-2009
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Quote:
Originally Posted by JJ The Boat Wizzard View Post
NO i never said it would in a 10th car i said it could if you geared it wrong with a 'silly motor' so your giving wrong advice by saying ignor my post as lipos will never puff! and why do you have to argue with everything i say in every post clown im sick of arguing with you now if you want to try it plug a 2500 10C battery off of ebay into your 3turn setup and see what happens
so why are you banging on about thingd that are not relevent to the orginal posters question????
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