SMC 4000/25C/3.7V single cell Hardcase pack.
11-18-2008, 08:23 PM
#61
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.
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.
11-19-2008, 12:03 AM
#62
Tech Initiate
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.
. Just trying to figure out if other racers would complain that lipo 13.5 has an advantage over 4cell 17.5.
11-19-2008, 05:03 AM
#63
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).
11-19-2008, 05:33 AM
#64
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!
11-19-2008, 05:46 AM
#66
There is no rule specifically saying lipo is not allowed in 1/12 scale, it just doesn't match the current specs.
11-19-2008, 05:55 AM
#68
Tech Adept
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.
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.
11-19-2008, 06:19 AM
#69
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!
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!
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.
11-19-2008, 06:43 AM
#70
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.
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.
11-19-2008, 07:01 AM
#72
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.
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.
) 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.
11-19-2008, 07:49 AM
#74
tttttttttt
