SMC 28C 4000/5000 Hardcase Lipo part 2
02-19-2008, 07:06 AM
#106
We appreciate you being a guinea pig. But I really hope your taking precautions with doing all that. Sounds extremely dangerous.
What about using a heat lamp over a salad bowl wrapped in aluminum foil with a grill placed on top. Put the lipo on the grill. Maybe use a small fan just to move the hot air around more evenly.
At least then you can watch it out in the open. Plus allowing another experiment. Keeping it hot while charging.
What about using a heat lamp over a salad bowl wrapped in aluminum foil with a grill placed on top. Put the lipo on the grill. Maybe use a small fan just to move the hot air around more evenly.
At least then you can watch it out in the open. Plus allowing another experiment. Keeping it hot while charging.
02-19-2008, 07:11 AM
#107
Danny we told you so, LOL.
Anyway... IMO 180*F+ is too hot by anyone's standards. You need to do some research into what the mfg state about max temps and safety etc. I agree that it's ok to get them warm... there must be a limit. I will bet that the performance will continue to improve right up until the battery goes nuclear. But that doesn't mean it's ok to push it that far.... at some point it becomes grossly irresponsible for a guy to do, and especially for a mfg/reseller to recommend. So we might be right back to where the other thread went if we aren't careful.
BTW, I tried to tell you I have a lipo-warmer that would help... and it won't get to irresponsible temps like 180-190... it maxes out around 140-150*
But I would recommend and be happy with @100-120 range for good performance without hurting the pack.
Dustin
Anyway... IMO 180*F+ is too hot by anyone's standards. You need to do some research into what the mfg state about max temps and safety etc. I agree that it's ok to get them warm... there must be a limit. I will bet that the performance will continue to improve right up until the battery goes nuclear. But that doesn't mean it's ok to push it that far.... at some point it becomes grossly irresponsible for a guy to do, and especially for a mfg/reseller to recommend. So we might be right back to where the other thread went if we aren't careful.
BTW, I tried to tell you I have a lipo-warmer that would help... and it won't get to irresponsible temps like 180-190... it maxes out around 140-150*
But I would recommend and be happy with @100-120 range for good performance without hurting the pack.
Dustin
02-19-2008, 08:19 AM
#108
Id like to see how your packs can help me on the track.I have many years of racing experience and have been matching cells for many years as well and I know how racers are always looking for that little extra. My concerns about Lipos not being any simplier than NiMh seems to be correct.
02-19-2008, 08:27 AM
#109
Once again please read some of my posts. My info is only for those who are looking for the best performance out of there packs and can actually benefit from a pack that runs at its best. If your not one of those then don't worry about all of this and just keep repeaking your Lipos and enjoy RC.
I have many years of racing experience and have been matching cells for many years as well and I know how racers are always looking for that little extra. My concerns about Lipos not being any simplier than NiMh seems to be correct.
I have many years of racing experience and have been matching cells for many years as well and I know how racers are always looking for that little extra. My concerns about Lipos not being any simplier than NiMh seems to be correct.
What is your judge of "best performane"? Certain #'s on a charger or laptimes? I judge performance on the track. Thats what Im trying to determine. Best Performance pack/methods for racing. If there was a contest on battery #'s then it sounds like you win. I want to know if that translate on the track.
02-19-2008, 08:32 AM
#110
warming LIPO's
Putting a lipo in an oven or on a heating pad just seems too slow. Have you tried putting the LIPO into a microwave???
We need exact times to heat up the pack, and the point at which the pack catches fire.
This is important to try, because we all know that pushing the extra .03v out of a pack makes all the difference in the world when racing. Race results can't possibly be largely based on driver skill, or else 1/2 the r/c industry would be out of business.
Keep up the good work. Oh, and by the way, the best charger for lipo is the fma scorpian charger, the only true balance charger on the market (doesn't bleed balance like every other balance charger.) And it's only $70.
We need exact times to heat up the pack, and the point at which the pack catches fire.
This is important to try, because we all know that pushing the extra .03v out of a pack makes all the difference in the world when racing. Race results can't possibly be largely based on driver skill, or else 1/2 the r/c industry would be out of business.
Keep up the good work. Oh, and by the way, the best charger for lipo is the fma scorpian charger, the only true balance charger on the market (doesn't bleed balance like every other balance charger.) And it's only $70.
02-19-2008, 09:02 AM
#111
Umm Bill.. You ever put metal in a microwave? 
EDIT:
I'm wondering for the electric gurus out there. Would a series of infrared leds put out enough heat to warm a pack to 150 degrees or so? Say like in a small box with a entire inner surface covered in infrared leds.
If that would be possible, that could be something easy to port and power at the track.
EDIT:
I'm wondering for the electric gurus out there. Would a series of infrared leds put out enough heat to warm a pack to 150 degrees or so? Say like in a small box with a entire inner surface covered in infrared leds.
If that would be possible, that could be something easy to port and power at the track.
02-19-2008, 09:03 AM
#112
Danny we told you so, LOL.
Anyway... IMO 180*F+ is too hot by anyone's standards. You need to do some research into what the mfg state about max temps and safety etc. I agree that it's ok to get them warm... there must be a limit. I will bet that the performance will continue to improve right up until the battery goes nuclear. But that doesn't mean it's ok to push it that far.... at some point it becomes grossly irresponsible for a guy to do, and especially for a mfg/reseller to recommend. So we might be right back to where the other thread went if we aren't careful.
BTW, I tried to tell you I have a lipo-warmer that would help... and it won't get to irresponsible temps like 180-190... it maxes out around 140-150*
But I would recommend and be happy with @100-120 range for good performance without hurting the pack.
Dustin
Anyway... IMO 180*F+ is too hot by anyone's standards. You need to do some research into what the mfg state about max temps and safety etc. I agree that it's ok to get them warm... there must be a limit. I will bet that the performance will continue to improve right up until the battery goes nuclear. But that doesn't mean it's ok to push it that far.... at some point it becomes grossly irresponsible for a guy to do, and especially for a mfg/reseller to recommend. So we might be right back to where the other thread went if we aren't careful.
BTW, I tried to tell you I have a lipo-warmer that would help... and it won't get to irresponsible temps like 180-190... it maxes out around 140-150*
But I would recommend and be happy with @100-120 range for good performance without hurting the pack.
Dustin
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 a fire and can be dangerous
Just because I'm doing some tests to actually figure out what helps and doesn't help doesn't mean I reccomend this but I do feel I can post my findings.
Some of you have stated that charging any higher than 1C will not yield any benefits. I did some tests and posted the results which seem to prove that a higher charge rate helps.
Then some said that if you get the pack warm/hot prior to charging it the results would be the same as charging it back up immediately after a 35 amp discharge cycle. This was correct but I decided to push the temp up and got better results.
So now we know that a 35 amp discharger is not necessary but I still feel it's the easiest way to get the temp up especially considering that your sure the inside of the cells/pack will be warm/hot by doing this.
After doing all these tests if I would be attending a Lipo race and wanted to extract the most out of my Lipos I would charge at 12 amps and get the pack to be atleast 140 degrees before I charge it back up. This can be done by using some kind of heating device or by discharging a fully charged pack at 35 amps.
Last edited by Danny/SMC; 02-19-2008 at 10:29 AM.
02-19-2008, 09:05 AM
#113
Tech Fanatic
iTrader: (1)
Danny...... or anybody
Is it possible that ??... If there is any change in the resistance in the load (IR of battery) on any volt meter.... Will you get different volt readings ??
What would happen if all volt readings were done with the volt meter at the same temperature as the battery as in the first volt readings ??
I am trying to understand how accurate all these readings are.
I hope you can understand what i am trying to ask you
Is it possible that ??... If there is any change in the resistance in the load (IR of battery) on any volt meter.... Will you get different volt readings ??
What would happen if all volt readings were done with the volt meter at the same temperature as the battery as in the first volt readings ??
I am trying to understand how accurate all these readings are.
I hope you can understand what i am trying to ask you
02-19-2008, 09:12 AM
#114
What is your judge of "best performane"? Certain #'s on a charger or laptimes? I judge performance on the track. Thats what Im trying to determine. Best Performance pack/methods for racing. If there was a contest on battery #'s then it sounds like you win. I want to know if that translate on the track.Racers have been using a T35 for years now and when a pack gives better results on a GFX it gives better results on the track. It may not be a huge improvement but trust me when the hardcore racers start using Lipos they will want to have any advantage even if it's a small one.
When I was at the Snowbirds you should of seen how many racers were bringing over multiple Brushless rotors and cans to the Novak pits to have the rotors gaussed out and the cans measured for IR to try and build the best possible BL motor. That is just the nature of the hardcore racer and that is in every type of racing not only RC racing.
02-19-2008, 09:19 AM
#116
Racers have been using a T35 for years now and when a pack gives better results on a GFX it gives better results on the track. It may not be a huge improvement but trust me when the hardcore racers start using Lipos they will want to have any advantage even if it's a small one.
When I was at the Snowbirds you should of seen how many racers were bringing over multiple Brushless rotors and cans to the Novak pits to have the rotors gaussed out and the cans measured for IR to try and build the best possible BL motor. That is just the nature of the hardcore racer and that is in every type of racing not only RC racing.
When I was at the Snowbirds you should of seen how many racers were bringing over multiple Brushless rotors and cans to the Novak pits to have the rotors gaussed out and the cans measured for IR to try and build the best possible BL motor. That is just the nature of the hardcore racer and that is in every type of racing not only RC racing.
02-19-2008, 09:20 AM
#117
Lazer Guy: Not sure what your getting at ?
A GFX will charge the pack until it peaks then it will go into a discharge which you set the amp rate. It can go up to 35 amps which is what I use. The discharge will be a constant discharge from full charge to 6 volts then it will stop. You will then have the packs discharge time in seconds and mAh , average voltage and the packs internal resistance.
A GFX will charge the pack until it peaks then it will go into a discharge which you set the amp rate. It can go up to 35 amps which is what I use. The discharge will be a constant discharge from full charge to 6 volts then it will stop. You will then have the packs discharge time in seconds and mAh , average voltage and the packs internal resistance.
02-19-2008, 09:27 AM
#118
or8ital; Our 22C pack has been tested on the track and is faster than the Orion packs in actual laptimes. The test was done with an Orion 4800.
I did test a 3600 pack and the average voltage and IR was not really better than the 4800.
Our new 28C packs have a better average voltage than our 22C pack and the IR is 4 milliohms lower. Once again this is the info were getting on a GFX which should translate to better laptimes. If it doesn't then we just spent money on tooling and better materials for nothing.
I did test a 3600 pack and the average voltage and IR was not really better than the 4800.
Our new 28C packs have a better average voltage than our 22C pack and the IR is 4 milliohms lower. Once again this is the info were getting on a GFX which should translate to better laptimes. If it doesn't then we just spent money on tooling and better materials for nothing.
02-19-2008, 09:35 AM
#119
Danny, with your higher charge rates, are you certain the "benefit" you're seeing isn't also due to increased temperature in the cells? There is a lot of hard data to prove that anything above 1C is deeply detrimental to cell life, and can possibly lead to degradation in the cells that would make them more prone to fire. I know you say your cells can handle it, but you really should do some long-term testing and let people also know how it affects other aspects of the battery's life. I know some guys don't care, because they get packs for free, but for the rest of the world, knowing the potentially severe drawbacks to 3C charging would be useful. You're kind of throwing the advice out there like it's no big deal, but the effects are cumulative, not instant. How about doing 50 3C cycles compared to 50 1C cycles, and showing us how things like voltage and capacity hold up over time.
My understanding is that some LiPo manufacturers won't even sell you their batteries (to re-sell) if they don't feel comfortable with how you're using them. How does your supplier feel about recommending 3C charging? Are they okay with that? Have they told you it's "no problem?" And why don't they have a web page? Doesn't China have the internets yet?
My understanding is that some LiPo manufacturers won't even sell you their batteries (to re-sell) if they don't feel comfortable with how you're using them. How does your supplier feel about recommending 3C charging? Are they okay with that? Have they told you it's "no problem?" And why don't they have a web page? Doesn't China have the internets yet?
02-19-2008, 09:38 AM
#120
I'm wondering why you haven't been balancing your packs in any of your tests ? Is the life of the pack cut so short that balancing isn't an issue?