picco007

iTrader: (99)

Rick,

With all do respect. I will respect what you comment. But your time in the RC industry can sometimes keep you from understanding what us common racers see.

I understand bench testing well. You made the comment "But when you start comparing different brands and their discharge numbers, they do not always relate." THEY are not supposed to relate, we are talking about two different cell manufacters. That's the basis of this thread. We know your a fan of IB's or whatever. Don't worry, your not going to lose market share if that's what your worried about. Bench testing is what your matcher uses to give you the cells. If I gave you some 1.17's whether they were IB's or GP's and then gave you 1.19's of either of the brands you would definitely see a difference. That is bench testing.....and that does relate to performance.

The bench testing was done with fairly the same run time numbers and voltages. Crimson Eagle is an engineer and understands in how to compare.

The "bench testing" that was done earlier in this thread was done as a basis of discharge characteristics, Voltage is voltage which relates to more to rpm. Performance at the beginning or the end of the race is relative and what you want in a cell.

We common racers don't have the money to buy packs or receive packs like you factory drivers so we have to make decisions on what we see and hear. You have to understand that. Bench testing and performance go hand and hand. If you don't agree with my statement then your being hypocritical.

Bench Testing is the basis of getting numbers on those cells YOU get.

elvo

That's one of those things that a TurboMatcher won't tell you. You'd need a pretty sophisticated bench test to incorporate parameters like that.

An 8-turn motor is more efficient than a 7-turn (generally speaking), so there is an overall power gain there.
This is the butterfly effect in action: a small change in one parameter can have a big effect on other parameters.


Slightly off topic: voltage is a good thing. Both high and low voltages can flow big currents, it just depends on the resistance, BUT.... high voltages can do so more efficiently. That's why power lines (the ones with the big poles that give you cancer) are 10.000 volts or more.

John Malin

Here it is on level guys.... There are currently two and now possibly three decent cells to choose from. While Ib is not the default standard they are trying to make the overall best cell. Gp on the other hand seems like they are not worried that Ib might get it right anytime soon. Time will eventually show which is the best cell. It might turn out that some cells are better for some people and or applications than others. I personally am very anxious to see what the final regular production version of the Ib cell looks like. Currently we only sell gp cells but we are still interested in Ib cells as well. Perception is a weird thing. My perception is that Ib wants into this market and are doing some of their reseach and development in the public, much like X-ray has in the past. I feel sorry for those that thought they were getting the best available only to find out that a few weeks have gone by and a few revisions have also been put in play. Now their cells are not quite what they thought they were getting at the start. Kinda buyer beware in a way. Dont get me wrong I am not pointing fingers at any matching companies per se but at the manufacturer for a premature release. I understand what all the testing and feedback required would be and ya gotta start somewhere. Damned if you and Damned if ya dont.

mtveten

iTrader: (29)

I prefer the IB cells to the current crop of GP and this is why:

First off I have found the IBs to provide higher voltage for the 1st 30sec or so than the GP3700 @ a 30A continous discharge. Voltage taken every 30sec there after to about the 390-420 marker is equivelent to GPs. The GPs do provide slightly better voltage (about .1-.15V) from the 420 to begining of dump around the 440-450sec range. 300sec volt avg is higher with the IBs but the GPs have a higher volt avg over the full discharge curve. In general the GPs had a flatter voltage curve from begining to end with the IBs flat in the middle with steep initial drop and more tapper at the end.

2nd The IBs provide more runtime allowing me to push longer or run more motor in mod races. Runtime on the GPs was in the low 460sec range compared to the IBs just over 500sec

3rd Although the IBs are reported to have lower IR the packs I tester averaged only about .03IR less per cell. and was not noticible on the track.


On the plus side for the GPs I found:

The GPs were more resilent and gained voltage, at the expense of runtime by step charging them with a high initial rate of 10A with a peak rate of 6A. With a step charge profile the GPs had better voltage than the IB from the 30-210sec marker and felt as though they had more punch on the track. Runtime droped from 460 to just over 400sec discharging about 600mAh less.
The IB packs decreased in performance with the step profile and did not respond well to a charge rate over 6A or to being equalized down to a .1V/cell level.

Please note my GP/IB testing was done of the 1st batch of IB3800 and a recent batch of GP3700(about 5 weeks ago). Your results may vary.

For predominatly mod racing I would suggest the IBs for their superior runtime.

For Stock I think the GPs with a stepped charge profile would yeild the highest avg voltage for the duration of the race.

Bob Nilsen

iTrader: (1)

I think Tex meant to say GP3700s on line 2, right?

Jack Rimer

John, I perfectly understand your point. GP did the same thing to some extent. They made improvements over the life of the cell while keeping the same shrink. In fact, we caught all kinds of grief at the Snowbirds a few years ago for running "special" cells when in fact they were just the latest version of the cell we had aired in. With regard to some racers purchasing packs only to find out in a couple months that there is better stuff available: at the time they buy them they ARE the best available and any changes are slight and incremental. Competition in China to one-up the competition is rampant. Actually, I'm not a big fan of the constant tweaking that all the manufacturers are guilty of because it makes the matchers look bad. But, as you know, we are all at the mercy of the battery companies. We don't determine if or when they change a cell. All I can say is that if you are in the market for packs, don't go crazy and buy 8 or 10 packs. Buy only a couple at a time during this period of intense battery competition. At least the batteries are getting better from batch to batch unlike the Sanyo's which seemed to decline from date code to date code.

John Malin

Jack well said. I too have been telling people the same as you and danny have....just get a couple every so often. I think that makes more sense besides then you always got some freshies that should be really good.

rayhuang

iTrader: (5)

good point-I have been buyting two packs at a time. About two a month and selling off two or so a month. Although I am not a "great driver" I do love testing and more testing and for me its fun ot get two more packs and see how different if at all they are.

Also-I can remember as a past large volume GP dealer-there was quite a bit of fluctuation in product quality in the GP3300 cells. I would bring in 10,000 a month and get varyng reporst from case to case to month to month as to how good or bad they were from my customers. I can tell you-so far-IB has gone up and up and up in performance and reliability-not up and down and up and down and up and down. The first short button GP was a nightmare.

Jon Williams

iTrader: (5)

Definitely some good discussion on here, boys.

(As an aside, I would like to compliment mtveven on some valid observations on the differences between the GP and IB cells.)

One thing I do want to bring to light is that the latest batch of IBs is *extremely* good and the reliability factor has increased substantially. The initial runs of these cells were prone to deterioration and inconsistency. This is not the case with the latest batch. There is no observable deterioration and the voltage and runtime numbers are extremely consistent. I was grateful to hear nothing on my matchers while going through the latest batch. That's right--I said 'nothing'. The previous generations would crack and fizzle quite a bit if you didn't monitor their cutoffs acutely. Now, I can actually let them cycle out like another brand's cell.

As far as GP3700s are concerned, I like the cell. It's sturdy, consistent and can be treated just like the 3300s. It responds very, very well to deadshorting and the packs feel identical run to run. Having said that, there is no question that the IB cells are the stronger cell for stock and 19T. I'll have both types of cells with me for Vegas, but I know which one I'll be running in my rides.

teamgp

I noticed the same thing as I routinely cycled four packs of the latest IB batch with 30A DX that brought their temps up to 170F. I use a Futaba CDR-5000 charger and the voltage and runtimes have been very consistent. I did have some decent results with step charging them @7A till 3050mA @.5A till 3080mA and finally @6.5A till they reached a 5mV/cell delta peak. Three out of four packs increased their runtime by an average of 10s and the voltage increased throughout the entire discharge, but I don't remember how much. The fourth pack increased its voltage, but lost 4s of runtime.

I'll fire up the charger, do a few cycles and provide some pics of the charging results.

Of course I don't have any 3700's to compare results with though.

Jack2

iTrader: (1)

teamgp

Correction, I use a 4mV/cell (.24V/pack) delta peak.

josh69162

iTrader: (3)

I think one thing that needs to be realized is that IB is in this market for the sole purpose of benefitting the R/C community. While GP may have tweaked their cells to get the major tweaks out, IB is here to squeeze the last thousandth of a volt to get the most track performance possible. They aren't selling their batteries for cordless drills, or an alarm clock battery. They develope the cell with R/C cars in mind, and I think that is something GP hasn't really been doing, just because they collect enough revenue from the mainstream market. They don't need to worry about us. Leave it up to the matchers to make the cells better. But now that they have competition, I think the battery market will become extremely competitive. Especially if this third company (IP, I believe...) comes into play. We will see high numbers with full wallets at the same time.
-Josh

Danny/SMC

iTrader: (2)

Actually competition amongst cell manufacturers will increase cell performance and quality and keep the prices down. The end result is or will be better cells for the same or lower price.

josh69162

iTrader: (3)

I meant OUR wallets...
-Josh