SMC 28C 4000/5000 Hardcase Lipo part 2
#121
Tech Initiate
You're not supposed to actually drink the bong water.......
#123
I think its well proven over the last 20 years that packs that put out more volts with lower IR are faster on the track than a pack with less volts and higher IR........assuming you can stop from hitting stuff. If you hit stuff, .03 volts ain't gonna do you much.......but get in the A main at snowbirds and tell me with a straight face that .03 extra volts didn't help get you there....
Interesting info Danny, makes me chuckle a bit when I think back to.........weren't all Lipos packs supposed to be the same according to the lipo fanatics? Weren't there supposed to be no advantages to pushing them to the limit......yeah yeah, and brushless motors are all equal and can't be tuned....
I am getting similar reports from hardcore people who have switched to lipo, that different charging methods and such can increase voltage and lower IR, regardless of the battery they are using.....not just isolated to the SMC cells...
Later EddieO
Interesting info Danny, makes me chuckle a bit when I think back to.........weren't all Lipos packs supposed to be the same according to the lipo fanatics? Weren't there supposed to be no advantages to pushing them to the limit......yeah yeah, and brushless motors are all equal and can't be tuned....
I am getting similar reports from hardcore people who have switched to lipo, that different charging methods and such can increase voltage and lower IR, regardless of the battery they are using.....not just isolated to the SMC cells...
Later EddieO
#124
Danny,
I for one will say a big THANK YOU! I appreciate that you are performing these tests in a reasonably precise manner and posting the results for all of us to learn from. One would think that a forum called rc'TECH' would be to promote just such activities. I have no plans to perform the tests you are performing and will not follow certain procedures that your results indicate will deliver performance. However, your testing allows me to consider strategies that I may find useful without placing my own equipment at risk. It's my choice as to what I am going to do with my batteries and you are being "my canary in the coal mine" for which I am grateful.
So far I am not going to try the procedures you have found to be beneficial, but you may hit upon something that is, to me. You have taken a lot of flak for your efforts which I have generally found unfair. Yes the toys we play with can be dangerous and we must be responsible with them, but we are engaged in competition and that requires innovation and discovery. It seems many of those criticizing you don't appreciate the dangers that have been taken in the past to allow for the toys we have today. I can assure you that much of the knowledge we have today was not gained by one man performing tests and passing that detailed knowledge on to thousands of others. Rather, much of it was gained by hundreds of young men doing dangerous things at their local tracks while other racers laughed or cursed at the results. Ultimately I think your approach has made us all safer, if perhaps less entertained, and for that I am again GRATEFUL.
I for one will say a big THANK YOU! I appreciate that you are performing these tests in a reasonably precise manner and posting the results for all of us to learn from. One would think that a forum called rc'TECH' would be to promote just such activities. I have no plans to perform the tests you are performing and will not follow certain procedures that your results indicate will deliver performance. However, your testing allows me to consider strategies that I may find useful without placing my own equipment at risk. It's my choice as to what I am going to do with my batteries and you are being "my canary in the coal mine" for which I am grateful.
So far I am not going to try the procedures you have found to be beneficial, but you may hit upon something that is, to me. You have taken a lot of flak for your efforts which I have generally found unfair. Yes the toys we play with can be dangerous and we must be responsible with them, but we are engaged in competition and that requires innovation and discovery. It seems many of those criticizing you don't appreciate the dangers that have been taken in the past to allow for the toys we have today. I can assure you that much of the knowledge we have today was not gained by one man performing tests and passing that detailed knowledge on to thousands of others. Rather, much of it was gained by hundreds of young men doing dangerous things at their local tracks while other racers laughed or cursed at the results. Ultimately I think your approach has made us all safer, if perhaps less entertained, and for that I am again GRATEFUL.
#125
Please don't attempt any of the tests I'm performing or use a charge rate higher than 1C. Never warmup your Lipo packs. Doing any of this can result in fire and can be dangerous[/B].
Once again if your worried about cycle life or any other issues with using a higher amp rate for charging then don't do it. It's not up to me to decide what everyone should use for a charge rate. I'm just letting everyone know what I'm finding out and what I would do if I would be racing at the high end level.
I will test a 1C charge rate with a pack 140 degrees to see if it will cycle out the same as one with a 12 amp charge rate. By the way 15 amps would be 3C on a 5000.
Our Lipo manufacturer has mentioned that 3C charge rate is o.k. but will drop down the cycle life. Once again it's my opinion that the hardcore racers would rather have 50 strong runs on there packs then to have 100 that aren't as strong.
It's impossible for me to do all the tests and maybe some of you could do some of your own to prove some of your points instead of just quoting what certain Lipo experts or manufacturers are saying. It seems like I have to prove everything I say so it would be nice if you guys could prove some of the stuff your saying as well.
Once again if your worried about cycle life or any other issues with using a higher amp rate for charging then don't do it. It's not up to me to decide what everyone should use for a charge rate. I'm just letting everyone know what I'm finding out and what I would do if I would be racing at the high end level.
I will test a 1C charge rate with a pack 140 degrees to see if it will cycle out the same as one with a 12 amp charge rate. By the way 15 amps would be 3C on a 5000.
Our Lipo manufacturer has mentioned that 3C charge rate is o.k. but will drop down the cycle life. Once again it's my opinion that the hardcore racers would rather have 50 strong runs on there packs then to have 100 that aren't as strong.
It's impossible for me to do all the tests and maybe some of you could do some of your own to prove some of your points instead of just quoting what certain Lipo experts or manufacturers are saying. It seems like I have to prove everything I say so it would be nice if you guys could prove some of the stuff your saying as well.
Last edited by Danny/SMC; 02-19-2008 at 10:25 AM.
#127
Danny
I completely understand where you are coming from... and I think it's great that you are testing and posting the results here for all to see.
The only thing I would recommend is that when you post something like you did (with the 180* tests.... and wanting to get temps even higher...) you need to be clear that it us kids should not be doing this at home. And that these temps are outside what the mfg. specs allow. (assuming that's true in this case?)
I'm trying to help you out here... prevent the bashing that you took in the last thread.
For the record Danny did just say this:
IMO just be careful where SMC draws the line for proper lipo usage. There must be a point where hot is too hot? I hope we all agree that winning races at the risk of getting hurt isn't worth it.
I completely understand where you are coming from... and I think it's great that you are testing and posting the results here for all to see.
The only thing I would recommend is that when you post something like you did (with the 180* tests.... and wanting to get temps even higher...) you need to be clear that it us kids should not be doing this at home. And that these temps are outside what the mfg. specs allow. (assuming that's true in this case?)
I'm trying to help you out here... prevent the bashing that you took in the last thread.
For the record Danny did just say this:
Just because I'm doing some tests to actually figure out what helps and doesn't help[doesn't mean I recommend this but I do feel I can post my findings.
#128
Thanks Frank I'm glad to pass on my knowledge and results. It does get frustrating at times when the same 5 guys or so just want to refuse to believe what I have to say or challenge me to prove everything I say but in the end helping out is my goal and I will continue to do so.
#129
Tech Champion
iTrader: (38)
Yeah I agree that SMC should be aware of possible liability issues. Some kid puts his lipo in the over then burns himself on the melting plastic. When he says to his parents "well Danny from SMC said to do it" you gotta believe eventually one of those parents is going to sue SMC.
Perhaps I should get one of verndogs lipo plates and apply a 800 degree soldering iron to it before my race to get better performance. <- thats the kinda silly thinking some of these posts will spawn.
I dont think it is that no one believes you. I just think people question the risk vs the reward of doing so. Hopefully ROAR will put rules in place to stop all this non-sense. We can all be "equal" and safe or all be "equal" and unsafe. Why not go the safe route?
Perhaps I should get one of verndogs lipo plates and apply a 800 degree soldering iron to it before my race to get better performance. <- thats the kinda silly thinking some of these posts will spawn.
I dont think it is that no one believes you. I just think people question the risk vs the reward of doing so. Hopefully ROAR will put rules in place to stop all this non-sense. We can all be "equal" and safe or all be "equal" and unsafe. Why not go the safe route?
#130
"*To charge at greater than 1C (no more than 3C): You must use a Thunder Power 1010C charger in
conjunction with a Thunder Power Balancer (205 or 210) and data cable. Only ProLite 910, 1320, 2000 and
2100 cells qualify for charging up to 3C."
http://thunderpowerrc.com/PDF/THPSafetyWarnings.pdf
(I'm pointing out the bold, not the marketing about buying their charger.)
From people that have been in the lipo biz much longer. You cannot say one way or another that balance charging will effect . I have no issues with your tests. Its just not scientific which creates doubt. When you have a hypothesis, you research it before beginning experimentation.
I should also point out one of those that did tell you the heat was the cause of the IR, was Linger.
#131
glassdoctor: I understand what your saying but my goal is to point out the challenges I feel that Lipos will have in high end racing. As most will remember I have been against using Lipos in high end racing because I feel it will make racing to be not as competitive as it currently is. I also feel the info we have been given about Lipos being easy to maintain and use may not be as simple as originally thought.
What happens if you refuse to charge at 3C or warm up your pack to a certain temperature but all of sudden guys you were normally running with are faster than you but there doing all this crap ? You will either have to do it , just live with the fact you can't hang with them unless you do it or quit racing.
I should be happy that Lipos are now legal for racing as our Lipos have very good performance and were committed to staying on top of this market but believe it or not I just want RC racing to be competitive and fair. The current NiMh may not be the most reliable cells we have had but there is an abundance of great cells for everyone and this is reflected by very tight racing at the major races. How would you feel if you buy 140 dollar pack to go to a big race only to find out that your pack is obsolete because company X has a new pack that is .20 of a second faster on the track and it costs 175.00.
Anyway we can argue and debate all we want time will tell if Lipos or any other technology is or was the way to go.
What happens if you refuse to charge at 3C or warm up your pack to a certain temperature but all of sudden guys you were normally running with are faster than you but there doing all this crap ? You will either have to do it , just live with the fact you can't hang with them unless you do it or quit racing.
I should be happy that Lipos are now legal for racing as our Lipos have very good performance and were committed to staying on top of this market but believe it or not I just want RC racing to be competitive and fair. The current NiMh may not be the most reliable cells we have had but there is an abundance of great cells for everyone and this is reflected by very tight racing at the major races. How would you feel if you buy 140 dollar pack to go to a big race only to find out that your pack is obsolete because company X has a new pack that is .20 of a second faster on the track and it costs 175.00.
Anyway we can argue and debate all we want time will tell if Lipos or any other technology is or was the way to go.
#134
I hope I'm not frustrating you I agree you get a big THANKS for giving the testing and info you are giving out.
You have to understand though that some are very experienced with lipos and are concerned about how some things have been presented. You have admitted to being a newbie with lipos after all....
Some of us have been following the lipo scene and looking at discharge graphs etc for years and have a good idea how this stuff goes. But of course, not many have pushed the tests to the same limit or done them for the same reasons that you are doing them. And not every lipo cell is the same. So I do find it very interesting, and I think there is more to learn.
I've done things I can't recommend too. It's all good imo.
Dustin
You have to understand though that some are very experienced with lipos and are concerned about how some things have been presented. You have admitted to being a newbie with lipos after all....
Some of us have been following the lipo scene and looking at discharge graphs etc for years and have a good idea how this stuff goes. But of course, not many have pushed the tests to the same limit or done them for the same reasons that you are doing them. And not every lipo cell is the same. So I do find it very interesting, and I think there is more to learn.
I've done things I can't recommend too. It's all good imo.
Dustin