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Old 02-19-2008, 01:48 PM   #151
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Wow, I leave for a few minutes and have to read all through this already?!

Danny, hate to say this, there's a whole other realm to the Lipo thing rather than seeing performance increase from increasing temp or charge rate. The post/link by Syndrome would help to clarify a lot of thing, as well as pulling up and reading over reliable test results/graphs by several Lipo companies. There is a chart showing you the huge drop in life cycle when 2C, 3C charge is used over 1 C charge. Understandably a higher charge would yield best results, but you are forgetting that the internals chemicals are being heated up more during a 3C charge over the conventional 1C Charge. Wait a few hours, and you will see that either using 3C or 1C charge rate would not yield very much difference on the discharge data. Only thing is, there's like hundreds of pages of readings to get started on, amazing stuff.

About newer Lipo's coming to the market and being better than what we have, sure that's naturally to be expected as product improvement is part of the grand scheme of things. I don't see a problem with that. However I would say this, it shouldn't be an issue in off-road mod racing as we almost have too much power with current Lipo's as is to put down in 2wd and the rest. I consider myself one of the higher end racers, but that being said I donít want 50 cycles out of Lipos for best performance, as I am looking for far more.
Maybe other classes such as on-road/carpet would see more of the benefits of the stronger Lipo's batteries to come.

All that aside, I would like to comment on the CE charger thing and the belief that CE produces better equipments than others though. For many years I believed they were truly the best with the higher end charger/ discharger unit they manufactured, that their lower end chargers would have similar software and high-end components built in them. After all they are the same device that matchers use to charge and discharge cells, and put labels on them.

Not any more. Aside from the GFX I have used, their lower end chargers the blue Pit bull and the updated black Pit bull aren't written with very good software when it comes to charging NiMh's cells in general. The software written into the Checkpoint TC1030 yielded far superior and better results when bringing up NiMh (especially older NiMh's cells) to full peak each time without the repeated false peak's I saw in all Pit bull units (4 separate units in all) when back to back testing were done with both brands.

I tried nearly everything possible with all 4 Pit bull units far as changing mv values to compensate for unexpected drop back and false peak during the charge curve, but the lower quality software written into them cannot tell the difference between a true peak or a false peak most of the time, and shut down often, especially so on older NiMh's cell. The Checkpoint software did this with nearly no issue, and was far more impressive and consistent.

If lower cost chargers like Checkpoint (and some others) easily outperforms the lower end CE Pit bulls on back to back consistent full charge on NiMh cells, that leads me to believe otherwise that the equipment and software used in the lower endís CE chargers aren't made of the best quality components and software that their website claims are from taken their CFX cousin. So the argument that CE uses best equipment in their chargers versus other brands, I don't think is no longer the case at all, except when it comes to their high end GFX which is their exception to the rule.

I admit I was wrong to believe the CE is better than the rest hype in the first place. I know better now. I'm sorry I didn't realize this so much in the past, as it could have saved me some headache, lol. Other companies have closed the gap since then. I will no longer say CE makes the best chargers in that area to this today.
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Old 02-19-2008, 01:49 PM   #152
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Our original pack was long and thinner as it used 2 cells. For us to be able to make it fit in most RC cars we paid for tooling and got a 2S2P pack which puts out the same performance.

I will look into these packs and see what I come up with. The pack you listed the link for seems to be the proper size for RC cars minus the hardcase.
Actually, the dimensions listed on FMA's site are wrong. It's quite long, like 160mm. John managed to cram it into his TC5. I removed the board on one and squished the tabs down enough to fit it into an Orion platinum case. It ran exceptionally well, but I wasn't comfortable with my hack job on it.
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Old 02-19-2008, 01:50 PM   #153
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Yes it will increase the voltage but shouldn't be done. Tracks who allow Lipos should be checking packs to make sure they aren't above 8.4v
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Old 02-19-2008, 01:55 PM   #154
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Actually, the dimensions listed on FMA's site are wrong. It's quite long, like 160mm. John managed to cram it into his TC5. I removed the board on one and squished the tabs down enough to fit it into an Orion platinum case. It ran exceptionally well, but I wasn't comfortable with my hack job on it.
Where does it say on the FMA site that they use Saehan cells ? It seems like the cells they are now selling are new and something else. They mention a company in Australia ?
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Old 02-19-2008, 01:56 PM   #155
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Danny,

Have you tried intentionally overcharging the packs to say 8.5v? I'd be curious to see if that increases the voltage over the entire discharge.
See Part 1 of this thread. or are you trying to stir the pot?
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Old 02-19-2008, 02:07 PM   #156
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4wd Racer: As you race in offroad power of the battery should not be an issue but for those who race in classes where speed is limited due to motor then battery performance will make a difference.

Tony Moffre has been cycling Lipos for 3 months now and has always charged at higher C rate and even doing some overcharging. He has yet to have an issue and his packs are still very good. What is good cycle life ? 50 , 100 , 300 or 1000 cycles. As a racer myself if you give me the choice to go faster and run 100 cycles or run slower and run 300 cycles I will take the 100 cycles.

We also have the guy who tested our Helicopter 2200/11.1v/25C pack and tells us it keeps getting better after 50 cycles and is all that he wants to fly now. He uses the packs in a 3D Helicopter which is known to put way more loads on the packs than RC cars.

I guess some of you think our Lipo manufacturer is just a guy in his living room who has no clue what he's doing.
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Old 02-19-2008, 02:09 PM   #157
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Danny,

Have you tried intentionally overcharging the packs to say 8.5v? I'd be curious to see if that increases the voltage over the entire discharge.

One of Danny's team drivers was making a regular practice out of that very procedure you describe but at a much higher rate for several months, and posted his results and finding on another thread, and was pretty much comfortable with doing a procedure at the track around others that probably werenít aware of what he was doing. He did say though that it was not a SMC endorsed practice, and was entirely of his own doing. You'll have to do a search for it though.

Keep in mind, that is a Roar illegal procedure as taking your Lipo's to 8.44 vlt or more is subject to disqualification at an event, as well as a safety issue not only for yourself and those around you for such procedure not to ever be done in the first place.

Besides that, there are many other reason as not to do so, such as corrosion and build up on the lithium plates from repeated practice of a such overcharge procedure, and possibly eventually resulting in a fire once the plating builds up to a point from repeated overcharge treatments. The risk alone isn't worth it.
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Old 02-19-2008, 02:13 PM   #158
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Where does it say on the FMA site that they use Saehan cells ? It seems like the cells they are now selling are new and something else. They mention a company in Australia ?
It was independently confirmed a while back in John's TC5 thread. I haven't heard about them changing cells, but I suppose that's possible.

It's not hard to find a ton of praise for these cells in the R/C world, especially amongst the flight crowd.
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Old 02-19-2008, 02:23 PM   #159
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Danny, about cycle life, on the rc side of things, I think it's still early to say what would be consider good cycle life and far as trade off in performance when it comes to r/c racing. I know I am looking for more than what I’ve experienced with NiMh’s though.

I think the Lipo cells that SMC are bringing to the market may surprise you and some others in terms of cycle life and performance trade off they seem to offer. That is something we'll have to do a wait and see on once they hit the market.

I would be willing to bet that it would be far more than 50 excellent cycles considering what those poor Lipo's have been put through so far, if they can handle 183 temp, heck they can handle anything harsh thrown at them!, lol. haha.

If it wasn't mentioned earlier in the thread, when can we expect them to hit the market for us to do our own testing? on and off the track.
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Old 02-19-2008, 02:24 PM   #160
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See Part 1 of this thread. or are you trying to stir the pot?
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One of Danny's team drivers was making a regular practice out of that very procedure you describe but at a much higher rate for several months, and posted his results and finding on another thread, and was pretty much comfortable with doing a procedure at the track around others that probably werenít aware of what he was doing. He did say though that it was not a SMC endorsed practice, and was entirely of his own doing. You'll have to do a search for it though.

Keep in mind, that is a Roar illegal procedure as taking your Lipo's to 8.44 vlt or more is subject to disqualification at an event, as well as a safety issue not only for yourself and those around you for such procedure not to ever be done in the first place.

Besides that, there are many other reason as not to do so, such as corrosion and build up on the lithium plates from repeated practice of a such overcharge procedure, and possibly eventually resulting in a fire once the plating builds up to a point from repeated overcharge treatments. The risk alone isn't worth it.

Not trying to stir the pot. I'll have to go read part 1.

I realize it's against ROAR's rule to overcharge the pack, but so is charging above 1C. Since Danny is doing the testing I figured I'd ask to see if overcharging produces more voltage than he was getting with his 3C charge testing.
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Old 02-19-2008, 02:29 PM   #161
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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


I just wrapped up some more tests and to my surprise it seems like the reason why Lipos will provide better IR and average voltage is due to heat. I have done my normal back to back cycling 3 times in a row and on the second and third time the numbers were pretty much the same.

I then did a pack with 3 back to back cycles but the 3rd cycle was done at a 5amp charge instead of the 12 amp charge and the numbers were back like a regular 5 amp cycle.

So I guess heat is the solution and trying to keep the pack up in temp prior to running it. I will do more tests to try and figure out what works best.

Once again these tests are to prove how Lipos react to different charge rates/discharge rate and heat. Don't attempt this or do so at your own risk.
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Old 02-19-2008, 02:40 PM   #162
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You are allowed to charge at rates above 1C with no issues without breaking any ROAR rules, since the chargers with correct cc/cv software would arrive at the cut off in low 8.xx vlt regardless either way regardless of what C rate the Lipo pack is set at. (in addition ROAR rules does say you can charge beyond that 1C rate if Manufacturer says it's okay, with no loss in cycle life, etc. That's part of the fine print of using 1C rate or more)

That being said, Danny's testing at 2C-3C rates on his Lipo's pack is legal in a way. He is just sharing his finding with others through means that are currently legal. Although I'm not so sure about taking the pack past 140-150 deg though and the legality of doing so, lol. However ROAR does suggest 140 deg max temp, but I'm not entirely clear to the wording of that part. I don't really care to comment on that part though.

I think pretty much right now what's he's doing is helping everyone learn about what their Lipo are capable of (or those offered from SMC’s in a hardcase), I think. I do think that being said it's a good idea to do all the testing in an oven though, seems to be a safe place to me, lol. Heck, I would do the same!

It's taking Lipo's past 8.44 vlt that isn't currently permitted or legal by ROAR at the moment for obvious reasons...

Last edited by 4wd Racer; 02-19-2008 at 03:14 PM.
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Old 02-19-2008, 02:45 PM   #163
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4wd racer: I have no doubt that our Lipos have very good cycle life as the 3D Helicopter flyer is having great results.

Just because we use a manufacturer that is not Kokam, Enerland , Saehan or other mainstream manufacturers doesnt' mean that our supplier is not capacble of making some of the best Lipos. R&D and the use of the best materials is what makes a good Lipo and that is what they are doing.
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Old 02-19-2008, 02:51 PM   #164
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....double post, lol.

Last edited by 4wd Racer; 02-19-2008 at 03:09 PM.
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Old 02-19-2008, 03:31 PM   #165
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Just because we use a manufacturer that is not Kokam, Enerland , Saehan or other mainstream manufacturers doesnít' mean that our supplier is not capable of making some of the best Lipos. R&D and the use of the best materials is what makes a good Lipo and that is what they are doing.
Danny, I think it's awesome how you were able to work with and get Lipo's through a supplier your company trusts. Personally I don't care whose manufacturer you use. I have no issues if you don't use cells from the mainstream manufacturer, as I am certain the Lipo you outsource are just the same, if not better from the test data you've provided. I think that is what matters the most, and look forward to trying them out. Let me know when you plan to release them to distributors (i.e. a projected release date?)

Honestly to tell you the truth, this whole Lipo deal (having multiple manufacturer) is way better than in the days when we were at Tiltyard at the Norrca Nationals and talking with Homer about how Trinity was the devil and the whole deal, and we had to go through them exclusively then for the Sanyo (the only manufacture at that time that made a real cell for RC) NiCd 2000/2400 cells, except for Panasonics that were slowing working their way in the picture with a Trinity exclusive as well. Seems like nobody talks any more about how great Trinity is any more? Has the mighty fallen since then?! lol.
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