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Old 02-14-2007, 11:56 AM   #676
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They're most likely not allowed at big events, and you'll have to work a little bit to balance your car (get creative adding weight) because the LiPo is so light. Otherwise, it's a dream in comparison to NiMH.
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Old 02-14-2007, 11:58 AM   #677
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Mr. Black,

I heard a rumor that Kokam makes different grades of the cells used in the Orion packs. The story I heard is that the higher grade batteries are the same size, but have a much lower IR and better voltage. Of course, they're also a lot more expensive.

Is there any truth in this?
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Old 02-14-2007, 11:59 AM   #678
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The only thing i do is (duh) use a li-po charger but the batt is in my car all the time charging or storage

With li-po vs. Nimh you spend as much on 2 li-po's as you do on 3 Nimh but the li-po takes 3 times as long to charge
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Old 02-14-2007, 12:35 PM   #679
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Thanks for the replies....Should I purchase 2 or 3 or will one be sufficent for 3 5's and a 5 main.....or will I need to top off or swap out w/ a fresh charged Lipo?
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Old 02-14-2007, 12:38 PM   #680
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Chris G and I both only run 1 for 2 5's and a 5min main topping off after each race and when its race time we pull the batt fully charged or not
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Old 02-14-2007, 12:53 PM   #681
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thanks for all the help steve.amain have shipped it already.
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Old 02-14-2007, 12:59 PM   #682
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You can't go wrong with these batt.packs... And there not going to blow up on you like ppl like to say..lol Just don't run them passed 6.25Volts and you will be just fine..
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Old 02-14-2007, 01:02 PM   #683
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does your speed control have a cut-off if not the li-po cut off from novak is great and easy to install
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Old 02-15-2007, 09:21 AM   #684
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I apologize in advance if this is a stupid question, I didn't take the time to run it by R/C Tech's Appropriate Questions Committee.

I'm running the 3200 LiPo in a sedan with a Novak 13.5 motor (sintered rotor). As you may know, in order to make that motor fast, it needs a rollout in the neighborhood of 44MM. I've noticed that the car slows down significantly the last minute or so of a race, probably 3-4 tenths per lap, and it's very noticeable on the track. I'm trying to determine the cause of this, as it's affecting me in competitive races.

When the races are done, I put about 2200-2300 mAh back into the pack to get it fully charged. Is it possible that I'm hitting the downward part of the voltage curve once I get that deep into the pack's capacity? Presumably, I'm dipping into the last third of its power by the last minute of a race, especially considering it's probably not truly 3200 mAh after 4 months of use. I'm wondering if I'd be better served with the 4800 pack since we seem to be running these so hard in on-road.

Does that sound like a possibility, or should I be looking elsewhere for my trouble? My other possible culprit is that I'm heating up the stator of the motor too much (outside temp is about 140-150 after a race) and causing it to fade. I can address that with additional motor cooling and slightly more conservative gearing.

Again, sorry if this is a dumb question, hopefully the R/C hierarchy will have mercy on my mortal soul.
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Old 02-15-2007, 09:47 AM   #685
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Quote:
Originally Posted by syndr0me
I apologize in advance if this is a stupid question, I didn't take the time to run it by R/C Tech's Appropriate Questions Committee.

I'm running the 3200 LiPo in a sedan with a Novak 13.5 motor (sintered rotor). As you may know, in order to make that motor fast, it needs a rollout in the neighborhood of 44MM. I've noticed that the car slows down significantly the last minute or so of a race, probably 3-4 tenths per lap, and it's very noticeable on the track. I'm trying to determine the cause of this, as it's affecting me in competitive races.

When the races are done, I put about 2200-2300 mAh back into the pack to get it fully charged. Is it possible that I'm hitting the downward part of the voltage curve once I get that deep into the pack's capacity? Presumably, I'm dipping into the last third of its power by the last minute of a race, especially considering it's probably not truly 3200 mAh after 4 months of use. I'm wondering if I'd be better served with the 4800 pack since we seem to be running these so hard in on-road.

Does that sound like a possibility, or should I be looking elsewhere for my trouble? My other possible culprit is that I'm heating up the stator of the motor too much (outside temp is about 140-150 after a race) and causing it to fade. I can address that with additional motor cooling and slightly more conservative gearing.

Again, sorry if this is a dumb question, hopefully the R/C hierarchy will have mercy on my mortal soul.

Hi Syn -

I run the exact same as you... (rubber tires) and my temp is about 137 when I come off. My Roll out is 42.40 and have not noticed any fade.
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Old 02-15-2007, 09:59 AM   #686
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Quote:
Originally Posted by tbeardmore
Hi Syn -

I run the exact same as you... (rubber tires) and my temp is about 137 when I come off. My Roll out is 42.40 and have not noticed any fade.
Hey Todd. How many mAh go back into your pack after a race? Any idea what its voltage is when you first put it back on the charger? I think mine is around 7.4. It's 8.4 when it's done charging.

Charlie said a while back that if the stator in the motor gets too hot, it will definitely fade. With the sintered rotor, you wouldn't think that would be a problem. Maybe I'm just overgearing it, I just checked and I was closer to a 45MM rollout for my last race where it was VERY noticeable.
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Old 02-15-2007, 02:10 PM   #687
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Quote:
Originally Posted by syndr0me
I apologize in advance if this is a stupid question, I didn't take the time to run it by R/C Tech's Appropriate Questions Committee.

I'm running the 3200 LiPo in a sedan with a Novak 13.5 motor (sintered rotor). As you may know, in order to make that motor fast, it needs a rollout in the neighborhood of 44MM. I've noticed that the car slows down significantly the last minute or so of a race, probably 3-4 tenths per lap, and it's very noticeable on the track. I'm trying to determine the cause of this, as it's affecting me in competitive races.

When the races are done, I put about 2200-2300 mAh back into the pack to get it fully charged. Is it possible that I'm hitting the downward part of the voltage curve once I get that deep into the pack's capacity? Presumably, I'm dipping into the last third of its power by the last minute of a race, especially considering it's probably not truly 3200 mAh after 4 months of use. I'm wondering if I'd be better served with the 4800 pack since we seem to be running these so hard in on-road.

Does that sound like a possibility, or should I be looking elsewhere for my trouble? My other possible culprit is that I'm heating up the stator of the motor too much (outside temp is about 140-150 after a race) and causing it to fade. I can address that with additional motor cooling and slightly more conservative gearing.

Again, sorry if this is a dumb question, hopefully the R/C hierarchy will have mercy on my mortal soul.
Wow - 44mm rollout! Is it a large open track? Sounds pretty high to me? In the 40's is what I run with a 540 silver can motor...
What are the other guys running at the track then compare it with what Novak recommend.
Cheers,
Tony
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Old 02-15-2007, 02:19 PM   #688
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So what do you say to the skeptics at the track who say that lipo's still have significant safety issues in response to why they are not accepted for competition. Others say the lipos are an unfair advantage, as they put out 7.4 volts, not 7.2, so you can't mix them in with nimh cars.
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Old 02-15-2007, 02:27 PM   #689
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Quote:
Originally Posted by r0adrunn3r
Wow - 44mm rollout! Is it a large open track? Sounds pretty high to me? In the 40's is what I run with a 540 silver can motor...
What are the other guys running at the track then compare it with what Novak recommend.
Cheers,
Tony
It's medium sized. The 13.5 is a different animal entirely, especially with the sintered rotor. Presumably it needs that kind of gearing because it's ALL torque.
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Old 02-15-2007, 02:35 PM   #690
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Quote:
Originally Posted by Iceracer
So what do you say to the skeptics at the track who say that lipo's still have significant safety issues in response to why they are not accepted for competition. Others say the lipos are an unfair advantage, as they put out 7.4 volts, not 7.2, so you can't mix them in with nimh cars.
I haven't had to convince anybody, our race directors were cool about it from the start. Safety is a valid issue with any battery, including LiPo. If someone is saying you can't use them because of safety, and they haven't actually investigated the issue for themselves, then it's a pretty sure bet they just don't want LiPo around and are hiding behind the safety issue to make their case. Trying to explain anything to people like that is generally a waste of time. By now, anybody that actually has an open mind about LiPo but is concerned about safety has investigated it themselves.

In general, the cells Orion uses (Kokam) have proven to be EXTREMELY safe, even more so than NiMH. Cheaper cells are more prone to spectacular fires. I keep my LiPo in a Liposack, and follow all the recommended safety guidelines. We haven't had a single LiPo incident at our track with about 60% of the racers using them for 6+ months.
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