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Discussion Starter #1
So...coming from a little bit of an electronics background:

Why do we keep jacking up the mAh on these 1-cells? My (long-time) understanding has always been that adding mAh's adds run time to a battery, even in the round-cell days. It was a constant gearing game to make your 1200 SC's last an entire 4-minute run without dumping; now we're up to what, 6800mAh's for 1-cell carpet oval? Why? Why so high on the mAH's, when we're *still* only running 4-minute races? Why do we *need* "6800 mAh" 1-cells? Why aren't my 5000/5200/5400/5600 mAhs "good enough" to even "be competitive" any more?

Does the "voltage" ("horsepower") stay "up" more throughout a run with the higher-mAh batteries or something? Why do we need a 1-cell that will "stay up" longer than the race length of 4 minutes (or even 4:30)?
 

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Think of it this way...if the battery was 4000mah and we used 2900 in a 4 minute run you'd use that battery from 4.2 down to probably 3.5 or so. With a 6000mah battery you would use the same 2900mah but the battery would come off at 3.8 volts....with 7000mah you come back at 3.9.... So the bigger the battery the longer the voltage stays higher.
 

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WELL PUT NICK--

HENCE FASTER LAPS-MORE LAPS-

WE ALL KNEW 10000 MAH PACKS WERE COMING-

WHEN ARE WE GOING TO 5 MIN HEATS ?

EVENTHOUGH THE 4.235 IS THE MAX PER CELL VOLTAGE STANDARD,THE AVG-VOLTAGES (we use in our applications) WILL INCREASE AS THE MAH INCREASE,EVENTUALLY WE MAY SEE AVERAGE PEAK VOLTAGES @ 4.20 IN THE FUTURE,UNLESS WE GOTO 2CELL RACING.

NICK YOU MAY JUST GET THAT 65 LAPS-GOOD RUN SAT!!
 

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WELL PUT NICK--

HENCE FASTER LAPS-MORE LAPS-

WE ALL KNEW 10000 MAH PACKS WERE COMING-

WHEN ARE WE GOING TO 5 MIN HEATS ?

EVENTHOUGH THE 4.235 IS THE MAX PER CELL VOLTAGE STANDARD,THE AVG-VOLTAGES (we use in our applications) WILL INCREASE AS THE MAH INCREASE,EVENTUALLY WE MAY SEE AVERAGE PEAK VOLTAGES @ 4.20 IN THE FUTURE,UNLESS WE GOTO 2CELL RACING.

NICK YOU MAY JUST GET THAT 65 LAPS-GOOD RUN SAT!!
Yeah had the ole small block running good with all those big blocks out there
 

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SMALL BLOCK (ins. policy) WAS THERE,I WOULD HAVE BEEN THERE BUT RUNNING OLD ELECTRICS FOR POWER-
YOU GUYS ARE ON NEW STUFF-I WOULD HAVE BEEN ON NEW STUFF IF IT WERNT FOR THE ATTACHED INFO----

SOON-VERY SOON I WILL BE THERE----



Greensboro, NC, United States 09/30/2012 2:00 P.M. Late train. Cerritos, CA, United States 09/26/2012 3:04 A.M. Departure Scan 09/26/2012 12:11 A.M. Arrival Scan Aliso Viejo, CA, United States 09/25/2012 11:10 P.M. Departure Scan 09/25/2012 8:38 P.M. Origin Scan United States 09/25/2012 7:16 P.M. Order Processed: Ready for UPS
 

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SMALL BLOCK (ins. policy) WAS THERE,I WOULD HAVE BEEN THERE BUT RUNNING OLD ELECTRICS FOR POWER-
YOU GUYS ARE ON NEW STUFF-I WOULD HAVE BEEN ON NEW STUFF IF IT WERNT FOR THE ATTACHED INFO----

SOON-VERY SOON I WILL BE THERE----



Greensboro, NC, United States 09/30/2012 2:00 P.M. Late train. Cerritos, CA, United States 09/26/2012 3:04 A.M. Departure Scan 09/26/2012 12:11 A.M. Arrival Scan Aliso Viejo, CA, United States 09/25/2012 11:10 P.M. Departure Scan 09/25/2012 8:38 P.M. Origin Scan United States 09/25/2012 7:16 P.M. Order Processed: Ready for UPS
New stuff? That's last years stuff.
 

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I was thinking of running a scx in our 21.5 2-cell class with a shorty battery from revtech. Would I be at a disadvantage running the 4500 100c vs the standard length 6900 100c? I guess what I'm trying to figure out is, maybe I should just run a gen 3 with a standard length higher mah. What do you guys think??

Thanks
 

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WHEN ARE WE GOING TO 5 MIN HEATS ?
Never...The big races ( Snowbirds/Ovalmasters ) with their turn out need all the time they now have to run the number of heats ran in the event. Example...last year's oval at the Birds had 48 heats. Adding just one minute... would add 48 more minutes to a round of qualifing. That would be 6 to 8 less heats and about 45 to 60 less entries. You could put more racers to a heat but, Mike has a good show now. If he stayed at 4 minutes all the racers would want to just run 4 at the local level. There-for we will just get faster as batteries last longer.

Just my opinion
I could be wrong
 

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CNS48,

Go ahead and use that shorty pack, 2 cell racing is a voltage thing not an amp thing. We use 3400mah 25c packs in our sports mod class in the SouthWestTour series with open speedo's and do just fine. 1700mah used in a 5 min run on average. Our last race had a friend doing the same idea with his SCX and a Protek shorty pack, worked out just fine.
 

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Our last race had a friend doing the same idea with his SCX and a Protek shorty pack, worked out just fine.
HEY!!! Who in OUR class ran a SCX Car?????

*musta been that JOHN character!
 

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Discussion Starter #14
Thanks for the clarification.

*Sheesh*. *MORE* $$$ to spend now just to even keep up... :/

See, I was just curious, as to why (when I last purchased a new battery) I was told "You don't need mAh, you need voltage". But the voltage in current 1-cell carpet oval racing is limited anyways, to 4.22 volts at tech. It was my understanding that the voltage didn't drop off *that* much in a 1-cell 5400mAh; that it would stay "up" throughout a 4-minute run. I think I'd use about 2200-2700 (about half the mAh) depending on the gearing in a 4-minute run, so why not run longer races? Or better yet, why not *limit* the mAh for 1-cell racing (yes, I *know* about the 17.5 Sportsman Truck, etc., but why isn't mAh "limited" in the other classes, like a "cubic-inch" limit? It's like trying to run a 302 against 396's...or even worse...LOL)...?

OK...so....what *is* the current battery (1-cell, of course) of choice? Or, better yet - what's (which battery is) keeping the "horsepower" throughout most of, if not for, an entire 4-minute heat/main?
 

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While mah may be somewhat proportional to voltage, some of the lower mah packs have more voltage on discharge. When using a gfx you can see which battery holds voltage longer on discharge. Some of my newer packs will hold a given voltage twice as long as my older packs. I think ir has more effect on voltage than capacity. V=IR.
 

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Jimmy, adding time to races, will drive up the tire bill, one of the things many racer complain about. Cost is something you seem to be focused on, why do you seem to want to change stuff, every change drives racer cost...
 

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Discussion Starter #17
LOL...I don't *want* stuff to change, especially having to spend more $$$, especially batteries/electronics/motors. *BUT* - I was just curious as to why we (well, the battery companies) keep jacking up the mAh, but yet (for 1-cell, anyways), we're LIMITED by the rules to 4.22 volts. That's just more $$$ *I* have to spend (along with tires, stators, rotors, springs, etc.) *just* to even keep up. *I* REALLY don't have the "carpet oval experience" (i.e., setup experience) that a lot of you guys have; and I certainly *can't* get the track time just due to the fact that there's not a "regularly-open" carpet oval track nearby. If it were up to me, I'd spend four nights a week at an R/C track somewheres...LOL But - a very understanding wife (who goes to the races with me), a job, family, etc. comes first.

I *like* R/C racing; I've been doin' this stuff since 1986. Ran good a few years, until I grew up (wife, kids, family, military, jobs, etc.). I'd just like to *be competitive* again when I do get to race, so that's why I ask questions, make comments, etc. :)

LOL...Bill was the one that suggested going to 5 minutes.

My thinking - if we're going to *stay* at 4 minute races, *why* keep jacking up the mAh? It seems like it's back to "battery of the week/month" again. Told my wife when I got back into this stuff a few years back, I wouldn't need to keep buying batteries/motors/ESC's....LOL...
 

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Jimmy,

The 1c has a bigger restriction than 4.22 volts Max charge - it has a MAX case size - that will limit (at some point) the max mAh size of the pack.

As far as the 4.22 being the max voltage - that's just the static charge voltage - the KEY is a battery that "HOLDS" it charge under load the longest -

Yeah, we have batteries that could run for a very long time (where as the old days we geared to KILL the battery in 4 minutes) - we still TRY that in way, but the BL motors are much more efficient, and the LIPO batteries hold their voltages so much better than Round Cells did - so there is a fairly small amount of discharge curve now - but until there is NO curve - guys will quest for MORE MORE MORE.

I still say a software guru could write a ESC program that you could program a voltage curve into, and it would adjust your Motor timing to be backed off early, and increase as the run goes on, increasing RPM as the voltage starts dropping - (When I first mentioned something like that - I was told "YOU WILL NEVER SEE R/C ESC's with a programmable interface, they would be cost prohibitive" )

As far as longer races - we've done longer races for years, until guys wanted to start running like "The Tour" and go back to 4 mins. I still run our 2c/21.5 car @ 5 minutes, and our SPORTSMAN 1c Truck class we run 5 minute quals w/ 100 lap mains.

On the Banked Concrete the truck main went 100/9:48.37- on the rug it went 100/7:46.15 .
 
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