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Old 12-16-2008, 09:54 PM   #631
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Originally Posted by John St.Amant View Post
they dont exactly fit in our cars ....
The cells that are sub-c LiFe cells are 950mah per cell so that would make a 6.4V 1900mah pack or a 3.2V 3800mah pack. The cells I tested got very very warm under 10A loads per cells. So that would put the abuse to be only 20A in the 2S2P pack and 40A in the 1S4P pack. Don't kid your self on the mah, there is no room for buffer, once the cells reached about 800mah, it dropped like rock.
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Old 12-16-2008, 10:41 PM   #632
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I have heard from a national champion that he gets a new lipo every month because they can't take the abuse a NiMH battery can. He has said that they fall off 3 or 4 tenths, where as NiMH won't do that. But, since he is sponsered, he runs what is given to him.
Sorry man but thats just garbage, unless your at the very tip of the spear and a single 1/10 of a second is the difference between first and second. For the average racer a good lipo will last, I've been running my orion 4800's(which I bought used) for well over a yr with very very little falloff. Granted I'm not and will never be at the national level.

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they dont exactly fit in our cars ....
Thats not correct at all, I have two packs of these sub-c cells. One setup for a t-bar car, the other in an inline configuration. Both fit great and my car worked fine with them.

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Originally Posted by trailranger View Post
The cells that are sub-c LiFe cells are 950mah per cell so that would make a 6.4V 1900mah pack or a 3.2V 3800mah pack. The cells I tested got very very warm under 10A loads per cells. So that would put the abuse to be only 20A in the 2S2P pack and 40A in the 1S4P pack. Don't kid your self on the mah, there is no room for buffer, once the cells reached about 800mah, it dropped like rock.
+1 to what trailranger wrote, when thay dump its like you hit a brick wall. In the testing I have done I had trouble making 8mins with a 17.5 and a 55 tooth pinion, 76 spur and out-of-the box Jaco prizms.
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Old 12-17-2008, 12:23 AM   #633
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2S2P (6V, 2200mAh) A123 pack fits the old 12th cars perfect. They have the same length as 3 Nimh cells, but diameter of the A123 cells is smaller (ř18)
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Old 12-17-2008, 01:01 AM   #634
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+1 to what trailranger wrote, when thay dump its like you hit a brick wall. In the testing I have done I had trouble making 8mins with a 17.5 and a 55 tooth pinion, 76 spur and out-of-the box Jaco prizms.
I remember back in the 1200 and 1400mah days trying to make 8 minutes in 6 cell stock 1/12th. We really had to manage our throttle to make run time. Even on the straights we wouldn't pull full throttle unless we were trying to make a pass or protect from being passed.
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Old 12-17-2008, 02:03 AM   #635
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With the 2300mah cells in a 2s2p format(4600mah) there is plenty capacity to run 8 minutes with 13.5, it's tight fit and you must shift things around but they fit well enough. The 2s2p pack is a shade under 12oz so that's close to 4 round cell pack(in the 4600mah range)
I've been running the 1100mah cells in a 2s3p(3300mah)setup and I'm very happy, the 1100's and 2300's are the same length but the 1100 in roughly the diameter of a double A cell so they give you a tad more room in a allready cramped space. I'm able to run 8 minutes with 13.5 and most recharges are in the 2600mah range so I have plenty to do a few laps to get the tires happy just before the race and enough for 10 or so laps after the race is over. My old GP 3300 4 cell pack is 9.5oz and the 2s3p pack is 9.25oz.....BB
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Old 12-17-2008, 06:07 AM   #636
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The set-up and tires for single cell didn't change at all for me on carpet. Will the setup change? Yes but the setup has changed over the years anyway. A 2 cell pack will be about the same weight so the whole "new setup" and "different tires" arguments will be the same.

If A123 wants to get into the market they need to make a sub C sized cell. Until this happens they'll be stuck with the plane guys. There are only a couple of companies out there building sub C LiFePO4 cells and they aren't very good.

You can't compare KVa ratings to get performance under load. Loaded RPM is the only way to make a true comparison.

One other thing that most of you guys are leaving out is MOD. It's too fast now and 2 cell will just make things worse. Plus 2 cell would have to be HUGE in order to have enough capacity to make time. I'm all for limiting the capacity a little but limiting all the way back to 2000 or 2500 mAh is a joke.

The future holds more companies releasing single cell LiPo's for 12th, oval, and World GT. SMC was first but there are others that are following.
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Old 12-17-2008, 06:43 AM   #637
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One other thing that most of you guys are leaving out is MOD. It's too fast now and 2 cell will just make things worse. Plus 2 cell would have to be HUGE in order to have enough capacity to make time. I'm all for limiting the capacity a little but limiting all the way back to 2000 or 2500 mAh is a joke.
Have you ever tried out a 2200mah 7.4v lipo and know for sure if it does not have the capacity to run 8 minutes?
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Old 12-17-2008, 06:54 AM   #638
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Actually, I ran a 7.4v 3000 mAh LiPo in mod and it didn't make time. Not even close. Plus it made the car even faster and that's not what we need to get more people running mod.
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Old 12-17-2008, 07:08 AM   #639
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Actually, I ran a 7.4v 3000 mAh LiPo in mod and it didn't make time. Not even close. Plus it made the car even faster and that's not what we need to get more people running mod.
Interesting...I've been all over the net trying to find a 3000+ mah lipo that can fit the 1/12 scale without hacking it up. Can you show me a link where you got yours.
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Old 12-17-2008, 07:11 AM   #640
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Thats crap (no offence). I've been running the same lipos in my TC for 6 months and I'm still as quick as ever. Running cost is way down compared to NiMH and the convenience is worth every cent extra I paid for the battery pack, which is already offset by the need for less packs and no equalising/discharging gear.

Lipo is coming because it's a superior technology
No offense taken. I've heard the same arguments when the brushless thing was being debated. It will save the hobby, it will be less expensive,blah blah, blah. I had to spend $200 on a speedo, and another $80 on a motor. Now I have to spend another $80 on the pulse motor. Yup, this has made me a believer. Now this debate continues with the lipo. And I'm playing Nostrodomus here when I say that the battery wars WILL continue, and at a much more expensive rate. I have had my NiMH for 6 months, and only now do I have to replace one pack. At $45 a pack, that seems cheaper than the Lipo way. Also, everyone wants to run lipo because they think it will even the playing feild. Thats crap too. Just wait and see, I know I am. Thanks for reading my .02

Last edited by MUDVAYNE; 12-17-2008 at 07:12 AM. Reason: I can't spell
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Old 12-17-2008, 07:37 AM   #641
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Interesting...I've been all over the net trying to find a 3000+ mah lipo that can fit the 1/12 scale without hacking it up. Can you show me a link where you got yours.
Made my own from Maxamps cells. Fit in my saddle pack car fine and I could wire them as 7.4 or 3.7 (3000 or 6000 mAh). I forget what exact cells they were but they cycled out at 3000 for a 7.4v pack at 30 amps.

Just look on their site and you can find cells that will fit. It takes a lot of the thin cells to get the capacity up and it's not exactly cheap but you can do it.
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Old 12-17-2008, 08:14 AM   #642
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Originally Posted by chris moore View Post
Sorry man but thats just garbage, unless your at the very tip of the spear and a single 1/10 of a second is the difference between first and second. For the average racer a good lipo will last, I've been running my orion 4800's(which I bought used) for well over a yr with very very little falloff. Granted I'm not and will never be at the national level.



Thats not correct at all, I have two packs of these sub-c cells. One setup for a t-bar car, the other in an inline configuration. Both fit great and my car worked fine with them.



+1 to what trailranger wrote, when thay dump its like you hit a brick wall. In the testing I have done I had trouble making 8mins with a 17.5 and a 55 tooth pinion, 76 spur and out-of-the box Jaco prizms.
So u have a123's in a 12th car,,
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Old 12-17-2008, 08:14 AM   #643
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7.4V 3000mAh is more than enough for 8min.You can even reach 8min with a 2000mAh 7.4V battery with modified speed (4 cell, 5.5 winds).
Probably there is something wrong with your cells.

And why should A123 cells have sub-C size? Buy a new chassisplate or glue the cells on the existing plate (You need just 1 pack)
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Old 12-17-2008, 08:38 AM   #644
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Yeah, 3000 may be fine for some tracks. We're still dumping with 4600 cells in 4 cell and cutting that in half will just make things worse.

Cyrul dumped at Cleveland with 4600's so even that was not enough.
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Old 12-17-2008, 08:50 AM   #645
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Yeah, 3000 may be fine for some tracks. We're still dumping with 4600 cells in 4 cell and cutting that in half will just make things worse.

Cyrul dumped at Cleveland with 4600's so even that was not enough.
You really can't compare MAH ratings betweeen lipo and Nimh batteries. Don't forget lipo's are more efficient delivering power than Nimh.

Take a 4600mah lipo and a 4600mah nimh batteries. The lipo battery will have at least double the run time.
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