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

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

Old 12-15-2009, 07:52 AM
  #1  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 489
Trader Rating: 7 (100%+)
Default LiFePO4 batteries

....

Last edited by ozvena; 01-27-2010 at 07:41 AM.
ozvena is offline  
Old 12-15-2009, 07:58 AM
  #2  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

curious about this too, as well as if any company is looking to submit these to ROAR for approval. They are down in voltage in comparison to other packs like lipos for sure, but I can still see some use for these.

As a side note, I shot a message over to the USVTA contact address I could find to see if they would make them legal. since they are safer than lipos, and put out less voltage + are heavier, seems they could work out since they are not "as good" as a lipo.
Cain is offline  
Old 12-15-2009, 08:51 AM
  #3  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 489
Trader Rating: 7 (100%+)
Default

...

Last edited by ozvena; 12-19-2009 at 02:21 PM. Reason: not to the topic
ozvena is offline  
Old 12-15-2009, 08:59 AM
  #4  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

personally I have no problem with lipos.

I just think the Life packs should be allowed and based on the specs, doesn't sound like there is a reason they shouldn't.
Cain is offline  
Old 12-15-2009, 12:16 PM
  #5  
Tech Regular
iTrader: (13)
 
GWH74's Avatar
 
Join Date: Jan 2009
Location: Adelaide
Posts: 254
Trader Rating: 13 (100%+)
Default

I just made this pack up out of some of the new green shrink wrap A123 26650 M1 cells (2300mA).
I have only run the once so far. Am using a 10.5 and they are stupidly fast. Sooo much punch in a 1/12 scale. They weigh 147g compared to 140g for a SMC 4900mA 1-cell pack And they JUST fit in the car.
To charge them i just use a B6 based charger. Still need to wire up a balance lead, but with these cells and these no real need to balance.
There are a couple of little circuits out there that allow you to charge them from a NiMH based charger and disconnect the battery when it is charger.
Attached Thumbnails 2s LifePO4 battery packs above 2Ah & under 400g-top-a123.jpg  
GWH74 is offline  
Old 12-16-2009, 01:59 AM
  #6  
Tech Master
 
Martin Hofer's Avatar
 
Join Date: Mar 2005
Location: Germany
Posts: 1,083
Default

same dimension as efra spec lipos, thus fits any car

power delivery and feeling are exactly the same you get from 5cell

tested with 3.5T modified and gave more than 6minutes runtime

http://shop.graupner.de/webuerp/servlet/AI?ARTN=98972
Martin Hofer is offline  
Old 12-16-2009, 02:28 AM
  #7  
Tech Adept
 
Join Date: Jul 2008
Location: Hong Kong
Posts: 233
Default

I also have tested self-made A123 cells on both 1/12 and touring.

For 1/12, I paired 2S1P with 10.5R in a CRC. balance is good and is lighter than 4-cell NIMH. the pack weights about 160g with wires.

For touring, I paired 2S2P with 5.5R in an xray. I have installed a battery tray for this to work since the pack is wider and higher than normal lipo pack. The pack weights about 300g. However, in touring, I feel lipo is punchier. i am not talking about top speed, but out of corner speed and the duration of the pack. maybe the discharge curve is flatter for lipo when under very heavy load.

I am all for A123 since it is very safe and the best part is I only need 2 packs for a whole day. I can charge the battery faster than the motor cools down. I usually charge it at 6 to 8A and it takes only 25 mins to charge. A123 is so amazing!
hardmankam is offline  
Old 12-16-2009, 06:06 AM
  #8  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

After contacting Dawn Sanchez at ROAR, sounds like they are open to the technology.

So if you have a company in mind and want the packs to be ROAR legal, drop them a message so they can work with ROAR to get the ball rolling.

Last edited by Cain; 12-16-2009 at 09:21 AM. Reason: Updated to better reflect what Dawn stated
Cain is offline  
Old 12-16-2009, 07:05 AM
  #9  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 489
Trader Rating: 7 (100%+)
Default

....

Last edited by ozvena; 01-27-2010 at 07:41 AM.
ozvena is offline  
Old 12-16-2009, 07:09 AM
  #10  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 489
Trader Rating: 7 (100%+)
Default

....

Last edited by ozvena; 01-27-2010 at 07:41 AM.
ozvena is offline  
Old 12-16-2009, 07:10 AM
  #11  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

I'll contact Dawn and get the info.

I have sent messages to Maxamps and A123 Systems.
Cain is offline  
Old 12-16-2009, 07:27 AM
  #12  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

I sent a message to Hyperion's USA distributor, empire RC. I didn't see any other info for contact, so hopefully thats sufficient.
Cain is offline  
Old 12-16-2009, 07:38 AM
  #13  
Tech Regular
Thread Starter
iTrader: (7)
 
ozvena's Avatar
 
Join Date: Oct 2005
Location: STL
Posts: 489
Trader Rating: 7 (100%+)
Default

....

Last edited by ozvena; 01-27-2010 at 07:41 AM.
ozvena is offline  
Old 12-16-2009, 07:50 AM
  #14  
Tech Legend
iTrader: (268)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 32,637
Trader Rating: 268 (100%+)
Default

Here is the latest from Dawn:

First thing to do is to have a MFG contact our Technical staff at [email protected] and [email protected] to request inclusion and they will let that entity know of the data we will require.

Dawn Sanchez
ROAR President
I'll be sending that info out to a few manufacturers who expressed interest in getting the packs approved.
Cain is offline  
Old 12-16-2009, 09:00 AM
  #15  
Tech Elite
 
Join Date: Feb 2004
Location: Chandler, Arizona
Posts: 3,273
Default

This will be my one and only post here on RC Tech.

Had I known the emails being sent to me asking questions were going to be used without my permission on a public message forum, I would have been more concise with my answer.

Yes. We are open to the LiFE technology in our rules - but not for 2010 as we have not received any data of the products and no requests for inclusion from any MFG willing to provide the necessary templates to build the specifications from..... meaning, we are open to work on this with the help of interested MFG's.

But, for 2010, we do not have any guidelines, rules or plans to alter the course we are currently taking with Lipo. Any further information can be found by contacting our Technical Director and staff so we can proceed into 2011 with this technology, if available and the membership is asking for it.

Dawn Sanchez
ROAR President
Dawn Sanchez is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.