SMC 28C 4000/5000 Hardcase Lipo part 2
02-22-2008, 04:59 PM
#212
Tech Fanatic
iTrader: (6)
Tony .... sorry but your wrong about the rule. We knew this way before it was even being made public on rctech. This rule was in the first drafts of the lipo rules. In fact I've know about overcharging for almost a year now. How did I know? The person that was instrumental in the writing of these rules explained this to me and how to tech for it way before I or he became involved with ROAR.
I appreciate your point, but if that's the intent make it clear and there’s no misunderstanding. As you said "To catch a thief you gotta know how to be a thief" so if it walks like a duck, quacks like a duck and smells like a duck wouldn't you think it's a duck?
I appreciate your point, but if that's the intent make it clear and there’s no misunderstanding. As you said "To catch a thief you gotta know how to be a thief" so if it walks like a duck, quacks like a duck and smells like a duck wouldn't you think it's a duck?
Last edited by schurcr; 02-22-2008 at 05:10 PM.
02-22-2008, 05:00 PM
#213
Now in a later post (since I posted my response) I see he does tell how to get up into the 8.5's and maybe that was the "missing" information from the other post. Above 8.5 is definitely not legal, that "overcharge" rule is very specific.
There seem to be two things being discussed here, and I'm a bit leery of both. Danny is using, say 3X C for charging and not (apparently...correct me if I've missed something) ending up with voltages outside what is acceptable. What he IS getting is getting significantly lower IR and some VERY minimal average discharge voltage and run time changes. Tony is, apparently, playing games with sensor leads, etc, (or has at least experimented with same) to get higher voltages. In reading the rules it seems clear that Tony's increased voltage is illegal therefore the method is of no real use. Danny's "processing" seems to be within the reality of how the rules were written, whether it meets "intent of the rule" or not.
It also seems that LiPo show a lot less voltage drop "off the charger" than batteries I'm used to.
02-22-2008, 05:25 PM
#214
I know I'm late in this but I wanted to add...Ruben, as our Competition Director, has expressed my personal views and that of the ROAR Executive Committee very well.
When it comes to our membership's safety, we are serious. The rules in the book are more an instructional manual of HOW TO BE SAFE and WHY.. for a reason. We posted the general reader on the website to explain the rules and the process of testing, for a reason.
We aren't kidding on this one. There are no second chances with safety or... somebody abusing the priviledge of racing our events and disobeying the rules.
Please, do not promote such things publically. If you want to help us catch that thief, email is a better method or Private Messages.
Ok, we have hijacked Danny's thread enough... I'm intrigued to read more .. please continue this awesome conversation.
Thank you for your time...
Dawn
02-22-2008, 05:56 PM
#215
Tony .... sorry but your wrong about the rule. We knew this way before it was even being made public on rctech. This rule was in the first drafts of the lipo rules. In fact I've know about overcharging for almost a year now. How did I know? The person that was instrumental in the writing of these rules explained this to me and how to tech for it way before I or he became involved with ROAR.
I appreciate your point, but if that's the intent make it clear and there’s no misunderstanding. As you said "To catch a thief you gotta know how to be a thief" so if it walks like a duck, quacks like a duck and smells like a duck wouldn't you think it's a duck?
I appreciate your point, but if that's the intent make it clear and there’s no misunderstanding. As you said "To catch a thief you gotta know how to be a thief" so if it walks like a duck, quacks like a duck and smells like a duck wouldn't you think it's a duck?
Oh, so if it looks like alot of CRAP, smells like alot of CRAP, and sticks to your shoe like alot of CRAP.........this must be alot of CRAP then huh!
Danny............
Sorry for the hijacking of your thread again.
Alot of us appreciate the knowledge and findings you have posted. Please keep up the hard work.
02-22-2008, 06:35 PM
#218
Scottrik: Somewhere in these threads... it was explained that the packs were charged to well over 8.4v, having nothing to do with the charge rate. I think that's what is being referred to with the overcharging stuff.
Dawn: right on... I hope ROAR has some teeth on this one.
It has the look not of ducks or crap. It's more like the cops walking up to a group of guys practicing auto theft and picking locks with all the tools of the trade etc, and then telling the cops it's all good, they are merely showing the boys how a thieves do it so they can keep an eye out for suspicious activity around the hood. You know... just being a good neighbor.
Still, it's not like nobody understood this stuff already and it's brand new idea. It may not have been common knowledge but plenty of us know you can push the charge voltage on a lipo to get a little extra out of it. And no doubt it will come out at some point... perhaps it's best to air it out now.
About the charge sensor leads... I'm not very familiar with the charger being used (I will have a GFX soon) but apparently the charger incorrectly reads the voltage without the leads hooked up. So.... that would mean that everyone using CE chargers are overcharging their packs if they don't use the leads. Do CE users normally use the leads?
Assuming this is correct I think CE needs to make sure everyone know it. I guess if they show up at a ROAR race they may find out the hard way.
Other lipo chargers don't have this "problem"
Dawn: right on... I hope ROAR has some teeth on this one.
It has the look not of ducks or crap. It's more like the cops walking up to a group of guys practicing auto theft and picking locks with all the tools of the trade etc, and then telling the cops it's all good, they are merely showing the boys how a thieves do it so they can keep an eye out for suspicious activity around the hood. You know... just being a good neighbor.
Still, it's not like nobody understood this stuff already and it's brand new idea. It may not have been common knowledge but plenty of us know you can push the charge voltage on a lipo to get a little extra out of it. And no doubt it will come out at some point... perhaps it's best to air it out now.
About the charge sensor leads... I'm not very familiar with the charger being used (I will have a GFX soon) but apparently the charger incorrectly reads the voltage without the leads hooked up. So.... that would mean that everyone using CE chargers are overcharging their packs if they don't use the leads. Do CE users normally use the leads?
Assuming this is correct I think CE needs to make sure everyone know it. I guess if they show up at a ROAR race they may find out the hard way.
Other lipo chargers don't have this "problem"
02-22-2008, 06:56 PM
#219
CE uses external voltage sensing leads cause they are FAR more accurate.......chargers that use combo leads, will not be as accurate....
I do have to ask, how is ROAR going to enforce this rule on overcharging.......so many variables factor into to measuring these voltages, that an innocent person could end DQed through no fault of their own.
Later EddieO
I do have to ask, how is ROAR going to enforce this rule on overcharging.......so many variables factor into to measuring these voltages, that an innocent person could end DQed through no fault of their own.
Later EddieO
02-22-2008, 07:37 PM
#222
It's up the local tracks and club to make sure that no one overcharges. The voltage of Lipo pack should not be more than 7.40 but I did hear that some chargers do charge a the pack a bit more than 7.40 so this is why I think the rule is 7.44 .
This past week I did allot of tests on figuring a way to make Lipos perform better. I now believe that Lipo performance is directly related to the packs temperature immediately prior to it being discharged.
So for those who are looking for maximum performance you should heat up your pack for awhile before you run it. There is no need to warm it up prior to charging and there is no need for charging at higher amp rates as charging cold down the pack.
This past week I did allot of tests on figuring a way to make Lipos perform better. I now believe that Lipo performance is directly related to the packs temperature immediately prior to it being discharged.
So for those who are looking for maximum performance you should heat up your pack for awhile before you run it. There is no need to warm it up prior to charging and there is no need for charging at higher amp rates as charging cold down the pack.
02-22-2008, 08:22 PM
#223
Ok, please forgive me on this but i want it VERY clear. To set you charger above a 8.40 amp charge rate is not legal? Is this correct? If that is the case how are you gonna stop it? Some sort of handout resistor device to cap your charge rate? I don't know, you guys tell me I would like the ROAR opinion. Am I right on this as far as the charge rate?
02-22-2008, 08:52 PM
#224
Volts, not amps HD. Not beyond 8.44 volts.
Good points though about how the 8.44 could still be compromised. Sounds like not only will they need to be teched in tech, but someone paying attention to the goings on in the pits.
If the GFX is so great with voltage precision, then why does it overcharge without the sensor leads? Yet chargers which do not rely on sensor leads do not?
Good points though about how the 8.44 could still be compromised. Sounds like not only will they need to be teched in tech, but someone paying attention to the goings on in the pits.
If the GFX is so great with voltage precision, then why does it overcharge without the sensor leads? Yet chargers which do not rely on sensor leads do not?
02-22-2008, 08:53 PM
#225
HD-F1, no, clearly you misunderstood what was being discussed in the thread earlier. I'll help clarify; "charge rate" and "overcharge" in terms of Lipo's are two completely different things.
Let's start with "overcharge", which is purposely taking Lipo's past the 8.40 vlt (+-.04) by overriding the charger's cc/cv software. Long as you properly charge your pack the normal way using your charger's cc/cv setting to 8.40 mark, you will be fine, and there should be no concerns here.
Then "charge rate", at this point ROAR has suggested you stay with the 1C max setting (this would be 5.0 for 5000 Mah pack, 3.2 for 3200 Mah pack etc), and states not to take it past 1C setting unless the manufacturer says it's okay to do so without any loss in cycle life. This seems to be the wording on this so far.
Let's start with "overcharge", which is purposely taking Lipo's past the 8.40 vlt (+-.04) by overriding the charger's cc/cv software. Long as you properly charge your pack the normal way using your charger's cc/cv setting to 8.40 mark, you will be fine, and there should be no concerns here.
Then "charge rate", at this point ROAR has suggested you stay with the 1C max setting (this would be 5.0 for 5000 Mah pack, 3.2 for 3200 Mah pack etc), and states not to take it past 1C setting unless the manufacturer says it's okay to do so without any loss in cycle life. This seems to be the wording on this so far.