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Old 11-17-2008, 04:43 PM   #406
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Originally Posted by Fred_B View Post
That pack wouldn't even fit in my 12th without moving all kinds of stuff around. Like I said before, if the A123 technology is so great why not put it into a sub-C size cell and go racing? Other companies have done it with LiFePO4 why can't A123?
I'm not against A123 but the current cells don't fit easily in the cars.
I did have to shift things around a bit to make room. In a sub-C size cell the capacity might be (just a quess) in the 1100mah range then to have enough run time a 3p pack would be needed so in the end the battery would take almost as much space, I have though the same thing so your not the only one......BB
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Old 11-17-2008, 04:47 PM   #407
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Not too long-winded? We are on post 400 already - LOL

I sit on the BRCA 12th Committee, with access into the EFRA Electric Committee. We hope to make proposals for 3.7v being used in 12th scale, and are all agreed that we cannot go back to 7.2/7.4v as the cars will be undriveable, bordering on dangerous. We hope this will allow the LiPo brigade to join in if they wish to.

We also hear the harbingers of doom saying there will be no NiMh cells, and we've been hearing that for two years! Nonetheless, like Mudvayne says, we too have had a steady increase in 12th drivers. No one has had any problems getting cells. No, it's not a stock item in the LHS these days, but that has helped. Shops that order for us get fresh supplies, so little or no dead cells, and usually very good numbers.

There is no lack of direction over here. What we do have is threads like this where people are trying to work out what they want to do, and causing confusion. That's why we want to try and set some Rules for using LiPo cells, so people can easily use them. There isn't any confusion in the Organisations, but these types of threads are very much less than helpful for getting drivers into the class. HTH
Everyone has there own opinion, thank you for the input......BB
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Old 11-17-2008, 04:50 PM   #408
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It's great to know that some of the "powers that be" are working on this, but please don't criticize the open exchange of ideas. The reason these people are doing all this stuff is because there is a feeling that nobody up top is "steering the ship" on this issue. Perhaps if the process were a bit more transparent or there were press releases about what's in the pipeline there could be more of a cooperative effort.

There are so many people out there willing and able to try new things that there's a real potential asset there for the sanctioning bodies. If an announcement were made that a few different specific approaches were being considered, instantly tons of people would be trying them out and offering a lot of feedback.
Well said and thank you.....BB
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Old 11-17-2008, 04:54 PM   #409
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Looks pretty trick. I take it the red and black lead just need to feed directly into the Lipo? I want to try this setup out.
Yup, just like a regular battery. I can draw up a picture of the layout and wiring if you like......BB
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Old 11-17-2008, 07:28 PM   #410
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Thanks Fred_B

Looks pretty trick. I take it the red and black lead just need to feed directly into the Lipo? I want to try this setup out.
Mine's waiting at the post office to be picked up tomorrow.

Red and black to the battery. I'm going to wire in a switch on the positive side so I can turn the car on and off easily. You shouldn't need to turn on the speedo.

Once I get back from Cleveland, I'm going to run some single cell stuff with one of the new SMC packs.
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Old 11-17-2008, 07:33 PM   #411
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I did have to shift things around a bit to make room. In a sub-C size cell the capacity might be (just a quess) in the 1100mah range then to have enough run time a 3p pack would be needed so in the end the battery would take almost as much space, I have though the same thing so your not the only one......BB

The pack I built with 4 sub-C sized LiFePO4 cells runs at 4100 mAh when wired for single cell. Voltage is around 3 volts under load.
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Old 11-17-2008, 08:12 PM   #412
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LOL You said "Load" ...
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Old 11-17-2008, 08:16 PM   #413
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So the SMC single cell packs are out now?
Are they the 5400's or 4000's
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Old 11-17-2008, 08:33 PM   #414
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Had to dig back to find the link. I've ordered a couple of these but haven't got them yet to run.
I did some bench test and I like!!!

The $5 3.7V to 5V convertors will work well for 1:12 and oval. I would not use them in Sedan or Off-Road. I ordered two just in case I fried one pushing the limits.

Test Setup

Tekin RSPro
4-cell EP4600
Spektrum 3100 Mirco ESC
Futaba 9606 Sevo
Novak 13.5 Motor
6.3V 3300UF Capacitor on Spektrum RX
Deans Connectors to ESC

First Test: 4-cell
Everything worked as it should!

Second Test: 3-Cell NiMH
I used a Deans to Aligator Clips to connect the battery using just 3-cell.
The ESC, SERVO and RX function. The ESC would studder about 2~3 times before the wheel would move. Almost 1/2 second delay before any real motion. Servo would hold stonger than the servo saver. Transit speed was decent.

Third Test: 3-CEll NiMH with 5-V BEC modual
ESC was in the off position. I took an old servo lead and striped the pos and neg wires and solder to the Deans to Aligator clips adaptor. This was to create an input power for the Modual. The RX powered on once I pluged in the Modual to RX. ESC/Motor Studder disappeared. Servo still held beyond what servo saver could hold. Transit was noticable faster.

I would have to say, Thanks to Tekin, Spektrum and Futaba. Using the same exact setup a few months ago I was able to run 415 laps on a single battery in a Enduro Run till it stops race. I took second by a few laps short, but still even with a pack barely showing 3.6V at the end everything worked till the motor just couldn't turn. The newer generation of electronics are more tolerent of Brownouts. So even if the 1.5A 5V modual should have a voltage drop, everything should sill work as my past experience showed.
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Old 11-17-2008, 09:51 PM   #415
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How big are the converters? Got pics?
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Old 11-17-2008, 09:57 PM   #416
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How big are the converters? Got pics?

http://www.hobbycity.com/hobbycity/s...ooster_for_BEC

Last edited by John St.Amant; 11-18-2008 at 12:10 PM.
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Old 11-18-2008, 05:52 AM   #417
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So the SMC single cell packs are out now?
Are they the 5400's or 4000's
4000 mAh @25C. I don't think any of the distributors have ordered any yet so You'll probably want to email SMC or 360rcspeedway to get one.
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Old 11-18-2008, 11:30 AM   #418
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Link didn't work
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Old 11-18-2008, 12:09 PM   #419
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I cut and pasted from fred b above .. try this one

http://www.hobbycity.com/hobbycity/s...ooster_for_BEC
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Old 11-18-2008, 03:12 PM   #420
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The 5V moduals are about the same size as a 3300uf 6.3V capacitor. 12mm x 25mm
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