Go Back  R/C Tech Forums > General Forums > Electric On-Road
2s LifePO4 battery packs above 2Ah & under 400g >

2s LifePO4 battery packs above 2Ah & under 400g

Community
Wiki Posts
Search

2s LifePO4 battery packs above 2Ah & under 400g

Thread Tools
 
Search this Thread
 
Old 12-16-2009, 05:18 PM
  #31  
Tech Fanatic
iTrader: (6)
 
Join Date: Sep 2001
Location: Chico, Ca
Posts: 808
Trader Rating: 6 (100%+)
Default

Originally Posted by Cain
I would be curious to see if they are used with 1/12 via a booster.
No need for a booster if you are running 2s at 6.6v. We didn't use boosters with 4.8v 4 cell configuration.

On the other hand 6.6v in a 12th with current gen of bl motors and esc would be insane after the carbon fiber showers when you hit the outside wall comming off the sweeper
schurcr is offline  
Old 12-16-2009, 11:11 PM
  #32  
Tech Addict
iTrader: (6)
 
Join Date: Dec 2005
Location: Belgium
Posts: 581
Trader Rating: 6 (100%+)
Default

Originally Posted by schurcr
No need for a booster if you are running 2s at 6.6v. We didn't use boosters with 4.8v 4 cell configuration.

On the other hand 6.6v in a 12th with current gen of bl motors and esc would be insane after the carbon fiber showers when you hit the outside wall comming off the sweeper
Driving it in a 12th with a 9.5 and the speed is the same as mod, very driveable. Of course it could also be that I'm the next Masami but I seriously doubt that.
Its ridiculous that everybody thinks that going higher in voltage immediately means more speed, has anyone else ever thought you can also go to a higher wind motor if its too fast??
Prolly more to do with the fact that the big battery company's have invested in Lipo instead of Life's.
Quante is offline  
Old 12-16-2009, 11:33 PM
  #33  
Tech Fanatic
iTrader: (6)
 
Join Date: Sep 2001
Location: Chico, Ca
Posts: 808
Trader Rating: 6 (100%+)
Default

Originally Posted by Quante
Driving it in a 12th with a 9.5 and the speed is the same as mod, very driveable. Of course it could also be that I'm the next Masami but I seriously doubt that.
Its ridiculous that everybody thinks that going higher in voltage immediately means more speed, has anyone else ever thought you can also go to a higher wind motor if its too fast??
Prolly more to do with the fact that the big battery company's have invested in Lipo instead of Life's.
Now drop a 5.5 or 6.5 in it and let e know if it's still as driveable. BTW ..... 9.5 is modified. If it can be made to go faster with a shorter wind racers will do it!!!!
schurcr is offline  
Old 12-17-2009, 03:00 AM
  #34  
Tech Regular
iTrader: (13)
 
GWH74's Avatar
 
Join Date: Jan 2009
Location: Adelaide
Posts: 254
Trader Rating: 13 (100%+)
Default

The punch in a 1/12 scale with a 10.5 and 2S A123s is great. Does not feel as soft as a 1-cell Lipo even when using a lower turn motor with the lipo. On a very loose asphalt track as the Tekin turbo spools up it gets exciting to say the least.
Great run time. Run it for well over 12 minutes, closer to 15. Motor comes off cooler then with 1-cell.
The available energy from the 2S pack is about 15Wh (2.3A x 6.6V). SMC 4900mA 1-cell is 18Wh.
So the A123 pack has less available energy, fast as a 1-cell mod (around a 5T motor) with nearly twice the run time and less motor heat (more efficient). Fast charge them in 15 minutes, dump them to the car stops, out last the life of the car and are SAFE. Conclusion.... Two thumbs up!

hmmm 3S A123 pack in an T2 009 this could get interesting.
GWH74 is offline  
Old 12-17-2009, 03:20 AM
  #35  
Tech Addict
iTrader: (6)
 
Join Date: Dec 2005
Location: Belgium
Posts: 581
Trader Rating: 6 (100%+)
Default

Originally Posted by schurcr
Now drop a 5.5 or 6.5 in it and let e know if it's still as driveable. BTW ..... 9.5 is modified. If it can be made to go faster with a shorter wind racers will do it!!!!
Then you can tell me why in gods name I would even consider to put in a 5.5 if 9.5 is already modified.... If you're trying to find reasons not to allow 2s Life's at least come up with something realistic...

If 9.5 is too fast for you, consider 13.5, 17.5 or 21.5; at least one of these will go slow enough for you.

But nooooo, its easier to go to a lower voltage cause the other one requires some thinking of what motor you can handle.

4 cell modified is also mostly driven with 4.5 or 5.5 allthough 2.5 is also available and if they really wanted 1.5 can also be made on 4 cells.
Quante is offline  
Old 12-17-2009, 03:22 AM
  #36  
Tech Addict
iTrader: (6)
 
Join Date: Dec 2005
Location: Belgium
Posts: 581
Trader Rating: 6 (100%+)
Default

Originally Posted by GWH74
The punch in a 1/12 scale with a 10.5 and 2S A123s is great. Does not feel as soft as a 1-cell Lipo even when using a lower turn motor with the lipo. On a very loose asphalt track as the Tekin turbo spools up it gets exciting to say the least.
Great run time. Run it for well over 12 minutes, closer to 15. Motor comes off cooler then with 1-cell.
The available energy from the 2S pack is about 15Wh (2.3A x 6.6V). SMC 4900mA 1-cell is 18Wh.
So the A123 pack has less available energy, fast as a 1-cell mod (around a 5T motor) with nearly twice the run time and less motor heat (more efficient). Fast charge them in 15 minutes, dump them to the car stops, out last the life of the car and are SAFE. Conclusion.... Two thumbs up!

hmmm 3S A123 pack in an T2 009 this could get interesting.
You're forgetting something, the A123 packs can be drivin till the car dies on the track. With Lipo's you need to keep, what is it 20% in the pack or else it goed under the required voltage. I think power output is about the same for the 2.
Quante is offline  
Old 12-17-2009, 03:40 AM
  #37  
Tech Regular
iTrader: (13)
 
GWH74's Avatar
 
Join Date: Jan 2009
Location: Adelaide
Posts: 254
Trader Rating: 13 (100%+)
Default

Originally Posted by Quante
You're forgetting something, the A123 packs can be drivin till the car dies on the track. With Lipo's you need to keep, what is it 20% in the pack or else it goed under the required voltage. I think power output is about the same for the 2.
Exactly. You can use 100% of the energy of the A123 with no fear of damaging the cells.

My main aim of playing with these cells was an option for club events. You could put a 2S pack in an old T-bar with a 27T brushed (or any cheap brused motors). The voltage is high enough to run the old brushed ESCs without boosters or receiver packs. So for $20 you can make a pay that chargers quick, last for 100s of cycles, safe and cheap for people to get into or use old equipment.
GWH74 is offline  
Old 12-17-2009, 08:02 AM
  #38  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 494
Trader Rating: 7 (100%+)
Default

...

Last edited by ozvena; 01-27-2010 at 07:42 AM.
ozvena is offline  
Old 12-17-2009, 08:48 AM
  #39  
Tech Legend
iTrader: (294)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 34,387
Trader Rating: 294 (100%+)
Default

I did manage to confirm that the LiFePO4 tech is legal in the RC Pro series, I contact Carlton Eppes and he advised me of this and I made sure it was ok to post . From what I can tell on the description on there site, the tech just can't exceed the voltage maximums listed. Send this post to carlton just in case any issues!

The Nitro offroad rules ironically have more detail on this as they list the 1/8 electric rules there.
Cain is offline  
Old 12-17-2009, 08:52 AM
  #40  
Tech Fanatic
iTrader: (6)
 
Join Date: Sep 2001
Location: Chico, Ca
Posts: 808
Trader Rating: 6 (100%+)
Default

Originally Posted by GWH74
The punch in a 1/12 scale with a 10.5 and 2S A123s is great. Does not feel as soft as a 1-cell Lipo even when using a lower turn motor with the lipo. On a very loose asphalt track as the Tekin turbo spools up it gets exciting to say the least.
Great run time. Run it for well over 12 minutes, closer to 15. Motor comes off cooler then with 1-cell.
The available energy from the 2S pack is about 15Wh (2.3A x 6.6V). SMC 4900mA 1-cell is 18Wh.
So the A123 pack has less available energy, fast as a 1-cell mod (around a 5T motor) with nearly twice the run time and less motor heat (more efficient). Fast charge them in 15 minutes, dump them to the car stops, out last the life of the car and are SAFE. Conclusion.... Two thumbs up!

hmmm 3S A123 pack in an T2 009 this could get interesting.
This sounds interesting. The bigest problem I see is the same problem we have with lipo. In the lipo beginings racing lipos didn't have the energy density we have today. As soon as LiPo became the new standard and accepted under the rules the battery mfr's started push for a better battery with much higher energy densities. The same will hapen with LiPoFE, and we don't need a battery with more voltage and possibly energy density.

At this point in time onroad doesn't need another battery that has the potential for more power or a battery/motor wind restructure that could hurt on road more than it would help.
schurcr is offline  
Old 12-17-2009, 08:54 AM
  #41  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 494
Trader Rating: 7 (100%+)
Default

...

Last edited by ozvena; 01-27-2010 at 07:43 AM.
ozvena is offline  
Old 12-17-2009, 09:05 AM
  #42  
Tech Fanatic
iTrader: (6)
 
Join Date: Sep 2001
Location: Chico, Ca
Posts: 808
Trader Rating: 6 (100%+)
Default

Originally Posted by ozvena
I think the rules when lipo came up should have been changed. It should not be the voltage but energy stored in battery packs as a limmiting factor.

May be not, because that would require some tinkering both on the regulatory body and users. Now, you want to be successful? You download setup sheets or buy a glossy magazine, why make it harder than that? Let me tell you, the best performing RC models are not to be found there, it takes time, experience and effort to make them.

ESC are sooooo expensive because we require high current. With 4s1p setup and smaller cells like 1100mAh thinks can run light, cooler, and more efficient. Cost of ESC, packs and motors would go down too. These cells are like $5-$6 each!!! Bigger 2300mAh are like $7-$8.

I can't believe that there is no reasonable $$ amount cap in stock classes. $100 for a stock motor (LRP Vector X-12 17.5)???

I can't believe that there is such a pressure that these life cells are not considered and even banned from non-ROAR races in my local club. Why would anybody care?
ROAR hasn't banned them, at least not that I know of. There are no rules or approval process yet but to say their banned isn't necessarly correct either.

As far as the cost of the cells. Sure they're cheap right now. Theyre not mainstream for racing. As soon as they become racing cells, and the battery guys start matching they won't stay as inexpensive as they are.

There is a retail cap under ROAR rules. maybe the $90 is a relatively expensive, but racers had no problem buyinig 3-4 brushed motors @ $3O each in the brushed days. How's that any less expensive?

As far as a lot of pressure. I've never seen LiFePO on the track anywhere. Unlike the lipo movement where masses were running it before it was legal.

Don't get me wrong, I'm not against LiFePO. I can see where they have their imediate place, bashing and propably 8th electric off road. I just don't see a future for them in on road especially in pan car. We just made a battery switch that only in the last 6 months has become the accepted standard across the US and Europe. Now you wan't ROAR to change that again
schurcr is offline  
Old 12-17-2009, 09:36 AM
  #43  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 494
Trader Rating: 7 (100%+)
Default

...

Last edited by ozvena; 01-27-2010 at 07:43 AM. Reason: added note about $$ cap
ozvena is offline  
Old 12-17-2009, 12:14 PM
  #44  
Tech Lord
iTrader: (3)
 
Join Date: Oct 2004
Location: Long Island, NY
Posts: 10,197
Trader Rating: 3 (100%+)
Default

Why are you comparing the motor price cap to batteries?

Ms. Sanchez has already described to you the procedure for having batteries approved by ROAR. Please begin that process, and let us know how it turns out. These batteries will not be approved because you started a thread on RC Tech.
jiml is offline  
Old 12-17-2009, 12:27 PM
  #45  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 494
Trader Rating: 7 (100%+)
Default

...

Last edited by ozvena; 01-27-2010 at 07:43 AM. Reason: updated my ignore list
ozvena is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.