Go Back  R/C Tech Forums > General Forums > Electric On-Road
Lipo c rating how far can we go? >

Lipo c rating how far can we go?

Lipo c rating how far can we go?

Reply

Old 12-20-2010, 03:53 PM
  #1  
Tech Fanatic
Thread Starter
 
b-man777's Avatar
 
Join Date: Sep 2005
Location: MA.
Posts: 942
Default Lipo c rating how far can we go?

Hey all: I've got two questions about lipo c rating.
1st Are lipo's getting to be like nimh batteries in that they keep packing crazy higher amounts of c rating in lipos like mah ratings in nimh batteries?
2nd Even if your racing can you really us all that power their stuffing into lipo's these days?
Thanks for the info and have a great holiday season
b-man777 is offline  
Reply With Quote
Old 12-20-2010, 04:27 PM
  #2  
Tech Fanatic
iTrader: (39)
 
tmaxx26power's Avatar
 
Join Date: May 2005
Location: Nebraska
Posts: 754
Trader Rating: 39 (100%+)
Default

It will always be a battery war no matter what type is available now and in the future.
tmaxx26power is offline  
Reply With Quote
Old 12-20-2010, 04:29 PM
  #3  
Tech Master
iTrader: (2)
 
Buckaroo's Avatar
 
Join Date: Oct 2010
Location: Norfolk, VA
Posts: 1,503
Trader Rating: 2 (100%+)
Default

Originally Posted by b-man777 View Post
Hey all: I've got two questions about lipo c rating.
1st Are lipo's getting to be like nimh batteries in that they keep packing crazy higher amounts of c rating in lipos like mah ratings in nimh batteries?
2nd Even if your racing can you really us all that power their stuffing into lipo's these days?
Thanks for the info and have a great holiday season
1. Just like anything else, it's all about different chemistry. As each new generation of chemistry gets more effecient and has a higher energy density, you'll see mah and C ratings continue to go up.

2. Yes, especially in Mod or higher KV motors. Probably the top packs are overkill for stock or VTA, but surely for some combos in mod and offroad, I don't think we've seen the ceiling on what we can do.
Buckaroo is offline  
Reply With Quote
Old 12-20-2010, 04:34 PM
  #4  
Tech Elite
iTrader: (55)
 
Join Date: Jan 2010
Location: VA Beach
Posts: 3,468
Trader Rating: 55 (100%+)
Default

I love my 65c TP packs. Capable of being charged at 31.8 amps. I double up the lipo sacks
Jamison R is offline  
Reply With Quote
Old 12-20-2010, 04:44 PM
  #5  
Tech Master
iTrader: (57)
 
billjacobs's Avatar
 
Join Date: Sep 2004
Location: Rockville, MD
Posts: 1,271
Trader Rating: 57 (100%+)
Default highest capacity

300c which is 300 x 5.5mah= 1650 amps. Of course no wire thinner than 6 guage could handle that, but hey, what's 1 pound in wire to get that extra .000001v to the motor.

If you look at the current batteries 65c x 5.3mah = 344 amps. The funny thing is that the dean's plugs are rated at about 40 amps continuous and maybe 120 peak.

As long as racers buy the latest and greatest without understanding how it will help them, the battery wars will continue. Like lemmings going off the cliff.
billjacobs is offline  
Reply With Quote
Old 12-20-2010, 04:52 PM
  #6  
Tech Elite
 
COBRARACING's Avatar
 
Join Date: Nov 2007
Posts: 3,333
Default

Heat is the only factor that kills battery cells .The c rating can go as high as it wants but if the grid is not designed or built properly then it doesnt matter the c rating the battery will fail under massive load which in turn creates heat and starts to build internal resistant thus damaging the cells and lowering the c rating .

if your battery company is serious you should ask them for a battery test sheet on your battery like we supply at pro amps .
COBRARACING is offline  
Reply With Quote
Old 12-20-2010, 06:58 PM
  #7  
Regional Moderator
 
CarbonJoe's Avatar
 
Join Date: Jul 2006
Posts: 2,663
Default

Most of it is marketing BS. The solder connections can't handle the rated discharge rate for very long without un-soldering themselves. As stated above, Deans connectors aren't rated for that current. Besides, the wires from the ESC to the motor aren't capable of that as well.

Reports were that some of the classes at Vegas were won with 25C packs. The spec classes are probably least affected by higher C rating packs.
CarbonJoe is offline  
Reply With Quote
Old 12-20-2010, 09:10 PM
  #8  
Tech Master
 
Join Date: Apr 2008
Location: Christchurch, NZ
Posts: 1,063
Default

I say unless you're pro, you don't need the crazy ratings. Like said above, they only make them because people buy them. I use 4000mAh 40C packs, and they have been perfect. Also, 1/2 the price of packs that won't give me anything more, and still top brands
JR007 is offline  
Reply With Quote
Old 12-20-2010, 09:15 PM
  #9  
Tech Elite
iTrader: (80)
 
pakk's Avatar
 
Join Date: Mar 2009
Posts: 3,082
Trader Rating: 80 (100%+)
Default

I thought higher C rating resulted in less voltage drop under load as well as higher amps.
pakk is offline  
Reply With Quote
Old 12-20-2010, 09:38 PM
  #10  
Tech Elite
 
COBRARACING's Avatar
 
Join Date: Nov 2007
Posts: 3,333
Default

To be Honest the c rating doesnt mean shit if your cells are of a low grade upon factory testing .Cells range from Grade A to Grade E were Grade A are the best ,come with a 1 year warranty or 800-1000 cycles .were grade E are rubbish cells that factorys recycle or pass onto the cheap narsty brands that relabel and sell and basically they come with a zero to 1 month warranty and 50 cycle charge .

so unless you have quality cells its doesnt matter what c rating you have it means nothing.

cheap cells means less cycles and poor quality .you get what you paid for.
COBRARACING is offline  
Reply With Quote
Old 12-20-2010, 11:32 PM
  #11  
Tech Elite
iTrader: (3)
 
Join Date: Jun 2003
Posts: 4,020
Trader Rating: 3 (100%+)
Default

In general my cars are faster with higher c rating packs irregardless of brand. More so in the slower motor classes. Confirmed by laptimes.

I think higher C rating packs (with higher storage capacity) have higher average voltage on discharge leading to better performance. Higher average voltage rather than max amp draw might be a better way of looking at it.

hth.
rccartips is offline  
Reply With Quote
Old 12-21-2010, 12:14 AM
  #12  
Tech Addict
 
Join Date: Nov 2008
Location: NZ
Posts: 678
Default

At last Im not the only one who thinks the high C ratings are BS.


Hyperion's product blub : a bit of honesty

"Note that NO CONNECTOR SYSTEM in use for RC Cars matches these rates, nor do RC cars draw such high continuous currents. Therefore if you intend to do CELL testing at max C rates continuously, hard case must be disassembled and appropriate cell connections made, by expert users only...."
1101 is offline  
Reply With Quote
Old 12-21-2010, 05:38 AM
  #13  
Tech Elite
 
COBRARACING's Avatar
 
Join Date: Nov 2007
Posts: 3,333
Default

This is what you need to ask for from your battery supplier to see if its BS or not .

At pro amps every single battery from the production line comes complete with its own test data sheet so you know its not bullshit .
Attached Thumbnails Lipo c rating how far can we go?-microsoft-word-pr60-5500-2s-report-page-1.jpg  
COBRARACING is offline  
Reply With Quote
Old 12-21-2010, 06:09 AM
  #14  
Tech Master
 
2wdrive's Avatar
 
Join Date: Mar 2009
Location: The Netherlands
Posts: 1,316
Default

do they produce saddlepacks as well?
2wdrive is offline  
Reply With Quote
Old 12-21-2010, 06:28 AM
  #15  
Tech Apprentice
 
Join Date: Feb 2010
Location: Sweden
Posts: 93
Default

Originally Posted by COBRARACING View Post
This is what you need to ask for from your battery supplier to see if its BS or not .

At pro amps every single battery from the production line comes complete with its own test data sheet so you know its not bullshit .
Well it's still only a piece of paper... i dont understand why a piece of paper coming from the manufacturer make it less bullshit than any other claim?

Is this Proamps your "own" brand?
From pictures i saw earlier it looked exactly like my Desirepower down to the wiring harness only the sticker looked different.
Are they made by the same factory in China?

I see they spec max IR as 8mohm i guess that's for the whole pack.
What does max IR mean? Are they to be consider spent when the IR climbs above 8mohm or 4mohm/cell?
What do they meashure per cell when new?

Are these to be considered as B or C grade cells as they spec 200 cycles down to 80% capacity at 1c discharge?
snabbgas is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Terms of Service