SMC 28C 4000/5000 Hardcase Lipo part 2
03-28-2008, 06:46 AM
#451
If you guys want the cells tested to a "standard" call it out and I'll bet that Danny can have the test run.
I can't find an ISO or ANSI standard for maximum cell discharge ratings and if you guys want to fight your way through the SAE site be my guest. Better yet, what "standard" is Kokam using to set the C rating of their cells. I'll give you a hint, I couldn't find it easily on their site either. Hiding something?
Go bust Orion's balls about their C rating and see what it gets you.
Ever wonder what Kokam tests to? I did and they have very little useful information available. Looks like they base their C rating on the cell not going over 140 degrees during diacharge. There's no mention of percent capacity for the "C" rating just temp.
As far as I'm concerned, we need our own standard for RC based on how we use the cells. Having a cell rated at a 140 amp continuous discharge is probably not the best thing to do.
I can't find an ISO or ANSI standard for maximum cell discharge ratings and if you guys want to fight your way through the SAE site be my guest. Better yet, what "standard" is Kokam using to set the C rating of their cells. I'll give you a hint, I couldn't find it easily on their site either. Hiding something?
Go bust Orion's balls about their C rating and see what it gets you.
Ever wonder what Kokam tests to? I did and they have very little useful information available. Looks like they base their C rating on the cell not going over 140 degrees during diacharge. There's no mention of percent capacity for the "C" rating just temp.
As far as I'm concerned, we need our own standard for RC based on how we use the cells. Having a cell rated at a 140 amp continuous discharge is probably not the best thing to do.
03-28-2008, 10:03 AM
#453
Our manufacturer uses the IEEE industry standard for Lithium Polymer battery testing. I know this may not be as useful for testing cells/packs for RC car racing but atleast they are following a standard.
I still think that using the T35GFX give us the info were looking for. When we get new NiMH cells to test and they look better on the Turbo Matcher which is the same as a GFX but for single cells it will be better on the track. So if a Lipo pack has better performance on the GFX it will be better on the track.
Other Lipo suppliers and resellers can all get a few GFX and print the info of there packs like we do.
I still think that using the T35GFX give us the info were looking for. When we get new NiMH cells to test and they look better on the Turbo Matcher which is the same as a GFX but for single cells it will be better on the track. So if a Lipo pack has better performance on the GFX it will be better on the track.
Other Lipo suppliers and resellers can all get a few GFX and print the info of there packs like we do.
03-28-2008, 03:01 PM
#454
If you think about it, why would our manufacturer choose an obscure number such as 28 to reflect the C rating if it wasn't 28C? Why not just use 30C? Well...because it isn't a 30C, it is actually a 28C. I'm sure many other companies are abusing this much worse than anything we could ever be accused of. The cell is 88% at 30C. I don't think it such a stretch to assume that it would be 90% at 28C.
The fact remains- when we came out with our packs we were blasted for not supplying data and told our claims of high performance were bogus. Now, since the packs have been released and we have empirical and real world proof, I somehow don't feel vindicated. Perhaps instead of debating whether the packs are as claimed on a machine, we should be comparing them to other packs on the track where it counts. I think our packs will hold their own on both accounts.
The fact remains- when we came out with our packs we were blasted for not supplying data and told our claims of high performance were bogus. Now, since the packs have been released and we have empirical and real world proof, I somehow don't feel vindicated. Perhaps instead of debating whether the packs are as claimed on a machine, we should be comparing them to other packs on the track where it counts. I think our packs will hold their own on both accounts.
03-28-2008, 03:21 PM
#455
Danny/SMC: ? about the 5200 saddle pack you mentioned earlier. I realise you don't have all the stats on this pack being you are just gearing up to produce these, but do you have any idea if this is going to be a camparatively thick pack or will your cells allow a lower profile to fit easier with less modding to the chassis, etc. The TrakPower is only a 4800 but they are pretty tall packs, just wondering what kind of height dimensions your 5200 will have? Thanks in advance.
03-28-2008, 06:13 PM
#457
You may not feel vindicated about their performance, but I do, because I've run them in my car & made a direct comparison ontrack, & I'm CERTAIN that they run at LEAST as good as my best NiMh's, & maybe a bit better(don't know if the pack will improve after a few cycles, & I've yet to try things like warming the pack), & that's more than good enough for me.....
Glad tp hear the pack is running well for you. As far as the pack improving I don't think it will as all my cycle info shows they stay very consistent but no signs of improvement.
03-28-2008, 10:35 PM
#458
Danny and Jack,
As I was afraid, I've been mis-understood. I will be purchasing a LiPo battery in the next few weeks and there is 100% not a doubt in my mind it will be an SMC battery. I've had excellent success with your NiMH batteries and am really not interersted in spending money for anything other than SMC products.
That said, the point to my previous post was that the data shown in Danny's post absolutely did not support the conclusion being stated. Again, I HAVE NO DOUBT THE 4000 BATTERY IS, IN FACT, 28C CAPABLE. The graph for the 4000 battery provided, though, does not support this--it shows that it is not 30C and is very comfortably 20C.
I have 100% confidence in the numbers you are advertising, I only caution that the conclusions drawn from any posted data should really be conclusively supported by that data.
Scottrik
As I was afraid, I've been mis-understood. I will be purchasing a LiPo battery in the next few weeks and there is 100% not a doubt in my mind it will be an SMC battery. I've had excellent success with your NiMH batteries and am really not interersted in spending money for anything other than SMC products.
That said, the point to my previous post was that the data shown in Danny's post absolutely did not support the conclusion being stated. Again, I HAVE NO DOUBT THE 4000 BATTERY IS, IN FACT, 28C CAPABLE. The graph for the 4000 battery provided, though, does not support this--it shows that it is not 30C and is very comfortably 20C.
I have 100% confidence in the numbers you are advertising, I only caution that the conclusions drawn from any posted data should really be conclusively supported by that data.
Scottrik
03-28-2008, 10:39 PM
#459
indeed. That ain't how legitimate testing is done and I'm sure Danny will be the first to agree. That's probably how some of thier competitors would go about it, but by all appearances SMC are making sure if they err it is on the side of caution. They've got a great product, no doubt about it. I'm merely trying to coach them toward a better overall argument WHY their product is superior.
03-30-2008, 08:00 PM
#462
To sum it up for you though: It should fit barely, but may cause an issue with the top deck when the chassis flexes. That being said I ordered the 4000. That has PLENTY of runtime.
03-30-2008, 08:09 PM
#463
Thanks for the feedback and I saw the dimensions listed but I am asking to see if someone has actually mounted the pack in the car? I saw the measurements as I mentioned in the 416 thread - but I am checking to see if someone has mounted the 5000 MaH pack in the car to see if there were any clearance problems.
03-30-2008, 08:37 PM
#464
You can run the 5000 pack. You just can't run any weights under it. That's why I went with the 4000 pack as well. The top deck clearance on the 416 is 25mm. And the 5000 is what... 24.5mm. So it gives a tad bit of clearance.
The 4000 pack runs great. Ran it this past weekend up in Maryland. No drop in performance in 13.5 class through the 5 minute run.
Danny, where do you clip the voltage leads when charging with the GFX. I think you posted a pic awhile back. But I think it was deleted during the server move while back. **Nevermind, the pic is back online..**
The 4000 pack runs great. Ran it this past weekend up in Maryland. No drop in performance in 13.5 class through the 5 minute run.
Danny, where do you clip the voltage leads when charging with the GFX. I think you posted a pic awhile back. But I think it was deleted during the server move while back. **Nevermind, the pic is back online..**
03-30-2008, 08:46 PM
#465
You can run the 5000 pack. You just can't run any weights under it. That's why I went with the 4000 pack as well. The top deck clearance on the 416 is 25mm. And the 5000 is what... 24.5mm. So it gives a tad bit of clearance.
The 4000 pack runs great. Ran it this past weekend up in Maryland. No drop in performance in 13.5 class through the 5 minute run.
Danny, where do you clip the voltage leads when charging with the GFX. I think you posted a pic awhile back. But I think it was deleted during the server move while back. **Nevermind, the pic is back online..**
The 4000 pack runs great. Ran it this past weekend up in Maryland. No drop in performance in 13.5 class through the 5 minute run.
Danny, where do you clip the voltage leads when charging with the GFX. I think you posted a pic awhile back. But I think it was deleted during the server move while back. **Nevermind, the pic is back online..**