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Old 11-18-2008, 09:23 PM   #61
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So you attach the voltage sensing leads straight to the 12 gauge wire ?

When you cycled the pack what was the room and pack temperature ? Cool pack temp and room temps will make the numbers look worse. When I cycle my test packs I normally cycle them once then an hour later I cycle them again and that is when I look at the numbers.

We have seen packs go up by 1 or so milliohm and others don't so were trying to figure out why this is happening but I'm not sure if we will ever figure it out.

I told a few of our sponsored guys to discharge there packs down to 6 volts at 35 amps and to store them like this. Based on what I have seen in my testing so far this seems to be the way to go. If someone would not use there pack for a long period of time I would charge the pack up until it reaches 7 volts and then monitor it once in awhile to make sure it's not dropping off to much as once a cell goes below 3 volts it will most likely be damaged.
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Old 11-19-2008, 01:03 AM   #62
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If anything, would the lipo 13.5 tend to be faster or slower than 4cell 17.5? It would be way too convenient for them to be dead on equal . Just trying to figure out if other racers would complain that lipo 13.5 has an advantage over 4cell 17.5.
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Old 11-19-2008, 06:03 AM   #63
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From what I've seen, 13.5 single cell is just a touch slower than 17.5 4 cell. The 13.5 single cell guys will probably have to find a weight that allows them to run about the same as 17.5 (kinda like the weight system for 5 or 6 cell sedan).
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Old 11-19-2008, 06:33 AM   #64
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Originally Posted by buffalobill989 View Post
are lipos even legal at roar sactioned 1/12 races?
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Originally Posted by Fred_B View Post
LiPo in 12th isn't ROAR legal yet but neither was 6 cell LiPo. It takes people trying the new cells and figuring out what needs to be done to get things rolling.

I'm running at big races with 4 cell but I plan on running LiPo when it makes sense.
Technically that isn't true. Right now most of 1/12 scale is 4 cell, which is 4.8v nominal. There is no lipo equivalent of a 4.8v battery. So, assuming this battery were ROAR approved (no reason why it wouldn't) you could run it but it would be like running 3 cell against 4 cell cars. There's also the weight problem, the lipo is much lighter than a 4 cell pack, so you would have to add a ton of weight to make 794 grams. So while the pack is legal, it's too much of a disadvantage to run it.

Donny Lia made a strong case for allowing the 3.7v lipo 1/12 cars to run at the upcoming Region 1 Carpet Championships. I was unaware that so many people don't run 1/12 because they can't run lipo (wusses!). It would require the lipo cars have a lighter minimum weight, and to use 13.5 motors, versus the 17.5 stock motors. According to Donny, in this configuration the lipo cars are the same speed as the 4 cell cars. The big sticking point was the availability of the lipo's. Because the race is only 2 weeks away they probably won't be legal, but maybe run a demonstration class for these cars.

Also at that race, on Saturday night December 6th is the ROAR Region 1 General Membership meeting. Open to everyone who loves RC cars. Be there. Aloha!
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Old 11-19-2008, 06:38 AM   #65
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so if i understand this correctly, you can run the lipo and it is legal it just has to be with the same motor as everyone else? thanks for the info
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Old 11-19-2008, 06:46 AM   #66
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so if i understand this correctly, you can run the lipo and it is legal it just has to be with the same motor as everyone else? thanks for the info
The only sticking point is the lipo isn't ROAR approved yet. If you assume it was, yea you could run it but you would have to run a 17.5 motor and make minimum weight. That would make it far too slow.

There is no rule specifically saying lipo is not allowed in 1/12 scale, it just doesn't match the current specs.
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Old 11-19-2008, 06:53 AM   #67
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Old 11-19-2008, 06:55 AM   #68
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So you attach the voltage sensing leads straight to the 12 gauge wire ?

When you cycled the pack what was the room and pack temperature ? Cool pack temp and room temps will make the numbers look worse. When I cycle my test packs I normally cycle them once then an hour later I cycle them again and that is when I look at the numbers.

We have seen packs go up by 1 or so milliohm and others don't so were trying to figure out why this is happening but I'm not sure if we will ever figure it out.

I told a few of our sponsored guys to discharge there packs down to 6 volts at 35 amps and to store them like this. Based on what I have seen in my testing so far this seems to be the way to go. If someone would not use there pack for a long period of time I would charge the pack up until it reaches 7 volts and then monitor it once in awhile to make sure it's not dropping off to much as once a cell goes below 3 volts it will most likely be damaged.

Yes to your ? I will try that what you suggest, the room was a little cool about 69-71 deg.
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Old 11-19-2008, 07:19 AM   #69
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Technically that isn't true. Right now most of 1/12 scale is 4 cell, which is 4.8v nominal. There is no lipo equivalent of a 4.8v battery. So, assuming this battery were ROAR approved (no reason why it wouldn't) you could run it but it would be like running 3 cell against 4 cell cars. There's also the weight problem, the lipo is much lighter than a 4 cell pack, so you would have to add a ton of weight to make 794 grams. So while the pack is legal, it's too much of a disadvantage to run it.

Donny Lia made a strong case for allowing the 3.7v lipo 1/12 cars to run at the upcoming Region 1 Carpet Championships. I was unaware that so many people don't run 1/12 because they can't run lipo (wusses!). It would require the lipo cars have a lighter minimum weight, and to use 13.5 motors, versus the 17.5 stock motors. According to Donny, in this configuration the lipo cars are the same speed as the 4 cell cars. The big sticking point was the availability of the lipo's. Because the race is only 2 weeks away they probably won't be legal, but maybe run a demonstration class for these cars.

Also at that race, on Saturday night December 6th is the ROAR Region 1 General Membership meeting. Open to everyone who loves RC cars. Be there. Aloha!
All it will take is a weight break for LiPo similar to the weight break that they use to allow 5 cell sedan to run with 6 cell. They probably won't be exactly the same but if people want to run LiPo we have to start somewhere

It might be a little early to try to get the new packs into a regional but I don't think it's a big deal to mix the two at a club level to get things rolling.
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Old 11-19-2008, 07:43 AM   #70
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I think this needs to be it's own class once the electronics are sorted out. This way the cars can run lighter which will reduce wear and tear. For this year maybe local tracks can allow them to race against sub-c cars but Lipo cars can run 13.5.

Bottom line is that Lipos are taking over and sub-c cells are harder to find as only 12th scale and oval racers are using them. So there needs to be a solution and this should be the way to go as it will give different speed options for particular tracks.
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Old 11-19-2008, 07:48 AM   #71
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Bottom line is that Lipos are taking over and sub-c cells are harder to find as only 12th scale and oval racers are using them. .

Are you still matching cells?....... and will you be doing it for a while. Now you got me scared with a statement like that.

.......... Plus I agree with a LiPo class running seperate for now.
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Old 11-19-2008, 08:01 AM   #72
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Yes we still match cells but not every week like we use to.

Anyone who has run Lipos will tell you that they really like it. So it's normal to try to get 12th scale and oval classes to try and switch to them plus single cell Lipo has an advantage over 2 cell Lipo as there is no need for balancing.
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Old 11-19-2008, 08:12 AM   #73
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thanks for the info. i only race at club level (and not much at that) but i will be running lipo 13.5 w/ the otheres and i dont think anyone will have a prob. i will bet that most of them will do the same.
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Old 11-19-2008, 08:49 AM   #74
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tttttttttt
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Old 11-19-2008, 01:00 PM   #75
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Originally Posted by KHoff7 View Post
I should be posting some pics of this pack wired up in my db12 with receiver pack Wednesday, and doing some 17.5 testing Saturday.
Cant wait!!
Its wednesday! picz pleaze!
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