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-   -   questions re: 3800 and 4200 for stock or 19t motor (https://www.rctech.net/forum/electric-road/122908-questions-re-3800-4200-stock-19t-motor.html)

cheehtae 07-25-2006 06:13 AM

questions re: 3800 and 4200 for stock or 19t motor
 
Maybe this question has been ask already or may have been existing somewhere in this forum, but just for the sake of argument let me give a scenario.

Same car
Same motor
same numbers on the batteries,just different Capacity.

?????
would the only difference between 3800 and 4200 be just the run time?
because right now most battery matchers or dealers are phasing out the 3800's and stocking 4200/4300's.

will the extra $10 be worth it?

4200/4300 are heavier too, isn't it one of the factors needed to be considered?

squarehead 07-25-2006 06:32 AM

Right now the voltage and internal resistance on the average IB4200 packs is considerably better than my "team" IB3800 packs. Runtime hasn't made a difference in stock or 19T since we had 3300s. In 4- or 6-cell, the punch and consistency they offer should be a LOT of difference in stock.

IMHO, I think that they will make every other battery a practice pack once they are legal everywhere.

ooliganRC 07-25-2006 07:23 AM


Originally Posted by ApexSpeed
Right now the voltage and internal resistance on the average IB4200 packs is considerably better than my "team" IB3800 packs. Runtime hasn't made a difference in stock or 19T since we had 3300s. In 4- or 6-cell, the punch and consistency they offer should be a LOT of difference in stock.

IMHO, I think that they will make every other battery a practice pack once they are legal everywhere.

sorry to gloat but they are already legal in the UK and have been for a while.

my suggestion is that if u get any ( matched or unmatched is to not charge over 6 amps as its not worth it.

secondly drop the pinion on the motor a tooth or too ( ie go smaller) as with the extra voltage you get more rpm.......

WhoMe 07-25-2006 07:47 AM

Time for the new battery debate again. Seems these new 4200 SHV cells are touted to have a significant advantage over the last generation of 3800s.

ottoman 07-25-2006 09:59 AM

What debate? The 4200's are better all around than the 3800's... nothing to debate. :nod:

WhoMe 07-25-2006 10:23 AM

Thats not the debate Im talking about..Its the cost of staying competitive one. But yeah I keep hearing that about the cells..however I havent gotten to use them or see them in action myself. My personel debate is weither I should just run my 3800s for the rest of the year or take the plunge now. I guess I would only upgrade if the difference was very significant.

ottoman 07-25-2006 10:40 AM

That would depend on how competitive you are/want to be. If you cant drive clean for 5 mins they wouldnt help. If your a A main type driver then they will be a little faster. I personally dont worry about the latest cells.... before a big race I buy a few new packs and then move them to club packs after the race.... just part of racing. The packs I rotate out I then give to the "sportsman" class racers.

HarshGuy 07-25-2006 11:00 AM

Well one thing, even though you probably won't have a runtime issue with 3800's I would imagine that you would have more voltage at the end of 5 minutes with 4200's than with 3800's ..that is actually how I "rate" my packs to decide which ones to use for racing i.e. what is left at the 5 minute mark Look here:

http://www.arroyoc.com/rcracing/harshbatcharts.pdf

And you'll see that even though all the packs I charted have plenty of runtime, the newer packs I have picked up have more voltage left at the 5 minute mark, which I wouls suspect that the 4200's have even more so.

DR VOODOO 07-25-2006 11:13 AM

Good ? but the answer is the same voltage rules .

A 4200 shv cell will run all over a 3800 cell a low 4200 cell will have a 1.22 average at 35 amps where a great 3800 would maybe be 1.215 There are 1.227 s out there at 35 amps and higher! + much more runtime .Dont want people thinking the 3800 s wont run but if any pro driver had there choice they would grap a 42 over a 38 anyday! hope this helps!

Grizzbob 07-25-2006 02:46 PM

Right, though there is one other factor that makes a BIG difference in whether it's a good idea to go with 4200's or not, & that's the driver. It doesn't matter how much of an edge you have in battery voltage, if you have even ONE bad hit on the boards during a race, you just wasted that edge, because every bad impact makes the motor draw a LOT of amps for a few milliseconds(& that takes the edge off the battery's voltage for that discharge cycle). However, if you can keep it clean & smooth for a complete run, time after time, then you may see the benefit of the better pack(but I know of few "mortal" racers who can do that regularly, myself included, I know I'm FAR from perfect). Now, all that being said, from what I've seen from the major matchers, the price difference(for packs of the same performance level, going from 3800's to 4200's) is what, five bucks? To me, that's NOT a significant difference, so it seems like a no-brainer to me, but you certainly don't have to buy any NOW, if you till have good 3800's, keep racing them until it's tme for fresh packs, & THEN get some 4200's(which is what I plan to do)..... :cool:

DR VOODOO 07-25-2006 02:49 PM

well said grizzbob!

squarehead 07-25-2006 04:25 PM


Originally Posted by Grizzbob
Right, though there is one other factor that makes a BIG difference in whether it's a good idea to go with 4200's or not, & that's the driver. It doesn't matter how much of an edge you have in battery voltage, if you have even ONE bad hit on the boards during a race, you just wasted that edge, because every bad impact makes the motor draw a LOT of amps for a few milliseconds(& that takes the edge off the battery's voltage for that discharge cycle).


Very true, but if you really think that way, then I have a box of 1700s in the shop that should still work fine for like 80% of racers who can't run a perfectly clean race.

The fact is, in the always changing battery & motor game with electric R/C racing, bigger is better. While I might not be able to make a perfect 5 or 8 minute run, the extra speed and power from a stronger motor or battery will also help to compensate for imperfect driving. I don't know any racer who thinks that slower motors or batteries are better for them—regardless of whether it is true or not.

And we as racers, regardless of costs, will always throw more power at the car in hopes of making up for any talent shortcomings. I'm not perfect, and at this point, I'm not an A-main racer anymore, but I'll take the 4200/4300s just to make up for what I lack in skill. I'm guessing most everyone else will, too.



Look, the battery complaint has been raging for 30 years in R/C. It won't ever stop, really. Don't bother bickering over it because it is a part of electric racing. By the time we all have 4200s in our pit boxes this winter, there will be one of the battery players ready to release a 4500 or a 4600. You know they are coming, so why worry about how fast everything you own obsoletes and just consider it a cost of racing electric cars?

Dragonfire 07-26-2006 03:42 AM

This is the same stupid question ppl always ask... If you can make runtime, why buy bigger batteries? Answer?
voltage
The newer bigger batteries sustain higher voltages for their discharge cycle. If you have more voltage, you have more speed and power.

The end.

Grizzbob 07-26-2006 02:46 PM


Originally Posted by ApexSpeed
Very true, but if you really think that way, then I have a box of 1700s in the shop that should still work fine for like 80% of racers who can't run a perfectly clean race.

The fact is, in the always changing battery & motor game with electric R/C racing, bigger is better. While I might not be able to make a perfect 5 or 8 minute run, the extra speed and power from a stronger motor or battery will also help to compensate for imperfect driving. I don't know any racer who thinks that slower motors or batteries are better for them—regardless of whether it is true or not.

And we as racers, regardless of costs, will always throw more power at the car in hopes of making up for any talent shortcomings. I'm not perfect, and at this point, I'm not an A-main racer anymore, but I'll take the 4200/4300s just to make up for what I lack in skill. I'm guessing most everyone else will, too.



Look, the battery complaint has been raging for 30 years in R/C. It won't ever stop, really. Don't bother bickering over it because it is a part of electric racing. By the time we all have 4200s in our pit boxes this winter, there will be one of the battery players ready to release a 4500 or a 4600. You know they are coming, so why worry about how fast everything you own obsoletes and just consider it a cost of racing electric cars?

You're right about that, but you need to read the last part of my previous post, my point was that if you have packs that are in good shape, you shouldn't feel so pressured to buy the latest & greatest, just for that little bit of extra voltage(for the reasons I already stated). But if you need new packs, then of course, the 4200's are a no-brainer. And about the price thing again, for those of us who've been doing this for over a decade(I've been at it for over 17 years), we've actually seen the price of the good stuff going DOWN over the years(seriously, when I got started, you had to pay $80 or more for cells that were just pushing 1.12 volts per cell at 20 amps, now we have cells putting out over 1.2 volts per cell at 35 amps & strong packs can be had for about $65-70). That's why I don't worry about it too much, just wait till a pack of mine needs replacing, & then upgrade..... :cool:


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