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Old 02-20-2006, 09:00 PM   #1
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Default Pros and Cons of using 4200 / 4300mah cells

What are the pros and cons of using these high capacity 4200 / 4300 mah batteries as compared with the 3700s/ 3800s.

The pros would obvisouly be longer run time, but I do not think that would be useful in stock and 19T racing unless you use it for pratice.If you are racing, you would not reuse the same pack without discharging and charging it back up again. With the 3800s now, there are already lots of runtime left after a 5min race.

The cons would be longer charging time. It would take an extra 5~10 mins to charge and longer time to discharge with so much runtime left.

Other then high capacity, do the 4200 / 4300 cells give out a high voltage and/or lower IR?

If I am only racing in stock and 19T, would the 3700 / 3800 be a better choice for me? The price between the batteries are $5~$10 so money woudln't be an issue.
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Old 02-20-2006, 09:13 PM   #2
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The middle of the discharge curve for these cells are relatively flat, but not totally...so with the higher capacity cells you will have slightly higher voltage throughout your run.

The tradeoff for this is higher weight as the 4200/4300 cells weight more than the 3800/3700 cells.

Feedback I have heard from several matchers so far is that the internal cell chemistry is basically the same between the different capacity cells but witht he larger cpacity cells having more of the chemical agents inside.

The net result is very similar voltages and IR with only higher capacity for those applications where too much just isn't enough.
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Old 02-20-2006, 09:26 PM   #3
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Be careful, the 4200/4300 can lasts more than 7 minutes on 8T but maybe not your speedo. I've seen some people melt their speedo because they run continuously until the battere empty on their practice.
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Old 02-21-2006, 04:18 AM   #4
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Quote:
Originally Posted by ChrisP
The net result is very similar voltages and IR with only higher capacity for those applications where too much just isn't enough.
Where does this information come from? My matcher only picked up 12 cells to mess around with. Both with higher voltages then 3800's, with lower IR's to boot.
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Old 02-21-2006, 07:02 AM   #5
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The information came from several different matcher's threads and was comparing cells from the latest batches at the time of launch of the 4200 and 4300 cells.

They are constantly tweaking the cell chemistry so it is perfectly reasonable that things could change. The newer batches will almost assuredly have better numbers than prior batches.
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Old 02-21-2006, 09:41 AM   #6
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Has anyone actually seen a production 4300? I keep hearing about them but I have not yet seen them on the shelf.....

Is GP doing a Microsoft? Vaporware???????
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Old 02-21-2006, 09:58 AM   #7
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Quote:
Originally Posted by XMSRacing
Where does this information come from? My matcher only picked up 12 cells to mess around with. Both with higher voltages then 3800's, with lower IR's to boot.

I also got the same results for a batch of 50. lower ir's i am getting 09-13 volts are consistent out of the 50 i only got 7 cells wich are 1.194 @ 30 amps. the rest were showing about 1.210-1.200v they are a much more stable cell but i did notice that the more you cycle these cells the more consistent the numbers get.

Usually i cycle new cells 4 times before i stick the lable on them. But i took the low batch of 1.19 and originally it started like a 1.16V with high resistance after 4 cycles it went up to 1.18 IR's kept getting lower. after 5 cycles it hit 1.193 i kept cycling it abotu 5 more times numbers would only fluctuate about .002 and the IRS would play around +/- 1 point.

My test was done on fresh IB4200 by Trinity with the Trinity wrapper. Zapped using an Integy 3000 zapper, matched using CE 4/35.
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Old 02-21-2006, 01:11 PM   #8
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<Bender engages "RANT MODE" >

Oh, great, the never ending updated battery saga

Pros: Drivers who buy these new cells WILL go faster, one way or another.

Cons: Once EVERYONE has gone out and bought these new cells, the status-quo will have returned - except that we will all be a few $ poorer

But, by that time the battery manufacturers will have their next "latest and greatest" version/update out, so that we can be ready to spend more $

Now before someone says "You don't need the new cells", or before this turns into a lipo debate, or a brushless vs brushed debate - let me ask everyone a simple question.

Why, when new cells are released, is everyone so keen on going out and buying them (even though they are initially illegal for competition use), without thinking of whether this is the right choice for the hobby?

The cell manufacturers seem quite happy to constantly try and outdo eachother, without thinking about what effect all this increased run-time and voltage will have on motors and esc's. They are doing this because WE the consumer, are running out and buying these new cells without thinking about whether or not we NEED them.

WE perceive that they will give us an advantage, but of course the cycle of past events tells us that once we all have the latest cells, we are back to where we started from (see Cons).

This instant buying of new (illegal) cells in turn puts pressure on our organising bodies to approve these new cells, even if they aren't "what's best" for our hobby.

The talk lately has been about motors and speedies being pushed to their limits by always-increasing cell capacity and voltage.

7 turn motors are now common - what will we see by the end of next year??
How will the current motor and esc situation be helped by us having MORE capacity available.

The 4-cell and longer race time ideas won't work - drivers will ALWAYS find a way to extract 100% of the capacity and voltage of whatever cells we use.

Unfortunately, IMO, we should have limited the capacity of cells a couple of years ago (at 3300) - their is only so fast you can go when you limit your source of power.

Seems like it's too late now......

<Bender disengages "RANT MODE", and puts on heavy-duty FLAME SUIT>
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Old 02-21-2006, 03:08 PM   #9
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Good Rant Bender - but why limit it to batteries - why not vent your spleen on car manufacturers, motor manufacturers, and ESC Manufacturers all producers of flavour of the month stuff, all contributing to the need to spend spend spend.
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Old 02-21-2006, 08:38 PM   #10
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Although I agree it can be difficult to keep up and has its downside.. we should never hold back technology developement for any reason. someday that 4300 will be the $12 stick pack and we will run all afternoon on a watch battery..... power storage rules the world and is the next great advancement due to move this rock forward.

Pushes all the manufacturers to get better and what pro level racing is all about....pushing the limits. Bring on the Power!!! We will figure out how to handle it.. you figure out how to enjoy it..

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Old 02-21-2006, 09:52 PM   #11
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Heavy- With the exception of cars, I don't believe their is a lot of "flavor of the month" equipment.

ESC's are fairly stable - maybe one update and/or new version every 12 to 15 months.

Motors are even more stable, at least the brushed motors are. V2's are quite old - yet still a popular choice, and many drivers still run the old Ti3 type motors. Perhaps in 19T there is a fast evolution occuring but this is because it is a relatively new class - it will slow down soon enough.

Even cars (with the exception of XRay and Tamiya) are not being developed in that short a period. Brands like HPI, AE, Losi, Schumacher etc seem much more "relaxed" with regards to their updates when compared to XRay or Tamiya.

Cells on the other hand have developed so quickly over the past 18 months (partly due to competing brands) that it's just silly. We've gone from 3300-3600-3700-3800-4200-4300mah in such a short space of time

I simply find it odd that most people agree with the idea of controlling costs via great ideas such as controlled tyres, yet are willing to spend up big on the latest cells at the drop of a hat

This is not a bash on any organising body, as I said : it is the consumer's obsession with owning the latest cells that forces those cells to be eventually legalised. If no-one bought the new cells would the manufacturers be still keen to rush back and develop more?

Ideally, with the exception of Mod, the slower classes should be more tightly controlled IMO.

Team Tekin-

Well I'm not sure I agree with those comments. If "someday that 4300 will be the $12 stick pack and we will run all afternoon on a watch battery" was going to be a reality, then wouldn't we already be seeing some of the benefits of this?

When I started racing we used 1200's. We now are approaching 4 TIMES the capacity- and yet we still run races of the same length

We really still don't have the opportunity to "run all afternoon" even with such a huge increase in capacity.

Remember, for racing, you only ever need enough capacity to finish the race at a competative pace: whether or not you can run 2 or 20 laps after the race is over seems a little irrelevant.

Finally, whilst I agree that Pro Racing is all about pushing limits - constantly improved cells affects not just the Pro's, but even the club racers.

As I said before, everyone wants a competative edge - and if new cells provide that, then racers will buy them.

Once that advantage has been demonstrated, the have-nots will also buy them so that they are not disadvantaged.

The end result is that everyone has ended up back where they started - except now they're going a little quicker, and being a little (or a lot ) poorer.

The only positive I can see is at least with all the battery-wars, the prices are kept down, so buying 3 or 4 packs is not quite the shock it was 5 or so years ago.
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Old 02-21-2006, 10:40 PM   #12
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Quote:
Originally Posted by bender
Remember, for racing, you only ever need enough capacity to finish the race at a competative pace: whether or not you can run 2 or 20 laps after the race is over seems a little irrelevant.
sorry but it is relevant.

when i run mod my 3800's have about 400mah left in them after the race.

if i had 4200's i may have about 800mah.

its obvious that the 4200's will be higher on the discharge curve and thus more voltage when the end of the race. which means more votlage over the course of the race. if you drew a discharge curve the 4200 will always sit equal or slightly above the 3800's at any point in time and especially near the end.

also as the cells age and lose capaicty over time, once a 3800 lose about 500mah of its capacity then it becomes pretty much useless for mod racing. but a 4200 can lose 900mah before it becomes useless

end of the day its up to you whether you can afford it. but for mod racing its definitly the way to go.

my 2c.
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Old 02-21-2006, 10:55 PM   #13
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...I don't know how the above question should really be asked, but it was posed that the question asker is running STOCK or 19T.

Depending on the Length of the race at his local track, I'd take HIGHER VOLTAGE which ever battery that would be.

When you have a 3700 or 3800 mah battery that will run nearly 8 minutes at MODIFIED amperage, in stock you should have nearly 4-5 minutes of runtime left. So, if that's true...at that point of the battery is where I'd mark MY voltage Cutoff. If you look at a battery that has a 1.120 "Average Voltage" that's taken down to .9v per cell and at THAT moment is where the Run Time is calculated. But that is NOT the average VOLTAGE of a RACE PACK during a RACE, that number would be close to what the voltage is at the 1/2 way point of an actual race. (I actually use Initial HIT voltage, 1/2 way voltage and 4(or now5) minute mark voltage added and averaged...)

If the initial HIT Voltage (About 2 seconds into the run) is
5.08 v and the 1/2 way is
4.87 v and the 5 minute is
4.78
____

4.91 would be the pack average I'm using. That would come out to 1.2275 "usable volts" per cell. I would also use the 4.91 Volt number when setting up the dyno for motor numbers.
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Old 02-21-2006, 10:59 PM   #14
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So would the 4200 / 4300 have an effect on stock and 19T racing?

I guess if the voltage curve is higher, then it must make more power.
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Old 02-21-2006, 11:17 PM   #15
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Quote:
Originally Posted by lookinco
So would the 4200 / 4300 have an effect on stock and 19T racing?

I guess if the voltage curve is higher, then it must make more power.

Yes,thats right.Your car will have overall more speed over the 5 mins compared to a lower capcity cell.
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