Danny/SMC

iTrader: (2)

I have said it many times in previous posts that my concerns are if Lipos become the power of choice for high end racing. At the moment it still seems like NiMH have an advantage but this may change if Lipo manufacturers keep working on improvements. I know our new packs will be better than our current pack and I expect other manufacturers to step it up as well and since there is so many of them I expect improvements to be made fairly often. The good news is that ROAR has set size limits so atleast that will keep some control on improvements.

As far as getting your Lipos to run faster it's not voodoo you just need a Lipo GFX or a Lipo charger and T35. You simply discharge your pack down to 6 volts at 35 amps then immediatley charge it back up. If you do this with a full pack you will get the pack to be hotter which seems to be what is making the increase in performance based on what Linger has mentioned. There is nothing super complicated about this and it works. Linger is saying that getting the packs warm/hot will do the same but I'm not sure what we could use to get the packs up to 150 degrees which is what a full discharge at 35 amps yields.

syndr0me

iTrader: (32)

The cell warming tray from MuchMore seems like a decent start. It gets hot enough to melt the skin off your fingers if you're not careful. What about a heating pad? Maybe even a smaller one like those used in reptile cages? If you can achieve the desired results without putting a hard cycle on the pack, that would be ideal.

I'm banning myself from this section of the site. :-) See you guys around.

JayBee

iTrader: (31)

You know I always gotcha back; just didn't want any harboring of animosity. I get enough of it already in my neck of the woods

Sigearhead

iTrader: (74)

I love the fact that guys like Danny, Jack, Josh, etc.. will come on these threads and post answers to our questions about their products. A select few like to stir the pot an point fingers, assume and take things out of context. I consider myself a hardcore racer and like to know that there is hardcore testing being done by some manufacturers to find out what can and can't be done to products. I am one of those who if there is a way to squeeze out (safely of course!) more performance out of my motors, batteries, tires, cars, whatever, I want to know.

On another note. I believe the MuchMore battery warming tray when used with your CTX cell master will warm your batteries to 35C which I believe is 95F. The SMC Lipo fits on there, the soft pack. I don't know about the new ones, and I know they won't heat up the lipo like a 35 amp discharge will but this may definitely be something to look into and tried. I don't know if the optional temp controller will heat them up hotter than that or not.
If you are like most, you show up a couple of hours before racing anyways and practice. Just run your packs, and charge them up a few times before the races and your pack should perform better as the days go on.

Sigearhead

iTrader: (74)

aaahhhhhhhh, somebody was reading my mind on the warming tray and posted first!

4wd Racer

iTrader: (8)

Danny, I'm pretty sure as the Cactus Classic rolls by, running your 2wd & 4wd under the hot Arizona sun will heat up the car and battery packs plenty past 100F on the track, as they are being run during practice. Just as Linger already described, running them in practice should be sufficient. Setting your Lipo's pack exposed to the full blast of sun’s rays on a pit table out of the shade for a while will help heat them up plenty well past 100F before a qualifier I would imagine as well. Things get pretty hot during the summer equipment wise. Probably no real need to discharge them fully at 35 Amps linear, then back up during those cases, but that's probably a good idea for the colder months in indoor facilities or when racing indoors (i.e. Cleveland on-road) I would imagine. I'm pretty sure though car warmers and battery heating trays could achieve similar effect as you described (the complete 35 Amps linear discharge procedure), and is far easier and safer than doing the other overcharge/cycle procedure as well. Just a few ideas, but I’m sure you knew all that.

Josh, even though much as the discussion got heated on this thread, I'm pretty sure for the most part it was civilized and there wasn't much crap thrown. I would like to think that most of the people you've seen on this thread that frequent RC tech know how to carry such conversations without going over the line. Sorry to hear that you had bad experience in the past years with the forums board, but once you get to know everyone again as I have (i.e. you learn who is credible with experience and who aren’t) , it isn’t all that bad.

Ted Flack

Well now. I tried to get some sleep and this thread got WAY to personal. I know there are strong opinions in this sport but this is crazy. I too enjoy a nice debate but this isn't "Nice".

Please you guys stop the personal attacks! It helps no one.

Let's debate about warming trays, that sounds like fun.

GO!

oXYnary

iTrader: (4)

There is only one area that this may be of concern: The manufacturer side. As like Trinity pushed packs (in example). Whose to say a pack from a manufacturer trying to get that edge over the competition may not be overcharged and cycled once or twice before reaching the consumer? I realize ROAR now need submission, but unless they can watch the entire step by step process..

Also, I realize companies thinking ahead will realize the bad press that could come from early failing cells or worse, law suits from burn victims. But the immediate benefit of sales for a manufacturer as people claim how well these new lipos perform may make them unconsciously blind to these later concerns.

Linger, if your still out there. When the lithium is turned into its metal state, would it have that temporary effect of the increased specs as earlier listed? As per the energy being able to conduct easier through the metal versus a ion state?

I should point out that Lipo isnt the end all of tech either. Its not like our hobby is going to stand still as it did so long with Ni-mh. Li-ion, A123, Li-Mn tech are also growing exponentially in development and usage. Plus other techs behind closed doors. So let us all not forget this when talking of the future.

But ehh, I run 1/18th. We are too fast as it is for the power we put in the cars.

kvrc

iTrader: (10)

in the matter of heating a lipo with a tray it wont be a good idea and here is the reason.
lipos are 2 or 4 cells that are the complete length and width of the pack. so if you just put it on a tray you will only heat up the bottom cell. it will need to be in a blanket like a heating pad so it heats up the top and bottom more evenly.

Davidka

iTrader: (86)

I use my pants pockets to warm my lipos. Get's them to right about 95*

I seriously do this though. I race on weekdays and leave my gear in my car (it's 3*f today) and put my lipo packs in my pockets for the 1/2 hour drive from work to the track. Works like a charm.

On this thread I have read about cycling to get the pack to get more performance which may or may not be caused by warming of the pack's chemistry and I have read about a method of charging that pushes the pack well past the manufacturer's limits using a current delivery (nimh charging) that is strictly forbidden by all lipo manufacturers. The difference between this conversation and every battery conversation before it (pre lipo) is that when a Nicd or Nimh battery fails the cell either vents or pops and while this can be a little dangerous to the user standing there, no fires will get started. If a Lipo is pushed over the edge the byproduct is hydrogen, it makes a hot fire that is hard to put out.

Danny, maybe you can get the ball rolling in the other direction by #1 offering a cycle life warranty for the packs you sell and #2 voiding that warranty if there is any evidence of overcharging or abuse.

Pushing and spiking relatively benign battery chemistries was fun and it worked but it just can't happen with this stuff. Josh, I hear you own a track. Thank you for choosing to do that. There are many easier ways to make a living but you choose to do it in a way that benefits the rest of us R/C racers too. You know better than anybody that you just can't have some kid is performing electrical/chemistry experiments in the corner with lipo packs. Your insurance probably wouldn't cover the damages.

jag88

iTrader: (1)

I hope Josh didn't put locks on the thermostats......

beavis353

iTrader: (4)

WOW what a great thread. I truly wish I had been able to read some of the posts prior to people coming to their senses. Thread entertainment at its absolute best.

Hey Danny, hope all is well. You back livin in the states?

Beavis

2-Bad

iTrader: (24)

Danny, several pages back you mention that you were going to post the dimensions of the 4000 and 5000 packs.
Has this been done or did I manage to skip over it amongst the incessant personal attacks that are lying around on this thread… And if they are handy, the part numbers of those packs too.

Thank-you

Danny/SMC

iTrader: (2)

The dimensions of the prototypes are:

5000
L-135MM W-47.8MM H 25.5MM

4000
L-135MM W 46.8MM H 20.1MM


We will get the 5000 to fit ROARs maximum specs as there is room for adjustments. Part numbers and pricing will be released in a few weeks. We expect to have our first production shipment by the end of February.

Danny/SMC

iTrader: (2)

All is going great. Not back in the states yet. Hope to be back at some races in the near future.