Lipos and sub-c parallel rule?

[Paul Pachmayer]

Hi Guys,

There's been many topics covering lipos use in FE and I'm thinking it's time to move forward. My thought is to introduce a max voltage rule in the larger cell count classes (24/32) so that lipos or what ever can be used. I DON't want to see them in the lower cell count classes yet. I'll come right out and say it, anyone with the investment of these large boats will more than likely respect the nature of the beast.

The other thing I would like to see is being able to parallel 24/32 cell packs to allow for lower current draws and higher capacity matching the Lipos higher numbers. I plan on using sub-c cells rather than Lipos and don't mind running against a lipo powered boat.

The other thing to talk about is running the bigger nitro size course, 330' straights and 35' turns. Even on a single set of batteries it's easy to go the distance.

Okay guys, how about your thoughts?

Paul.

 

[AlanN]

Right with you there big guy. Howie, Kelly, Doug Forrester are the main body of people I have discussed this with for the past year. Howard worked up the chart that did include ALL classes. I understand what you are saying about the smaller cell classes but I think they should be included. We would have to drop the M and O classes all together though. I really don't think they are neccessary anymore.

Howie is prob gettin his stuff to go to Batavia right now so when he gets back...I'll ask him to post the list. If I can ever get out of work today pack my car and sleep while driving I might just make Chi town....looking grim so far. But I digress.

We (CAFE) has been experimenting with the LiPos but have not had as much testing in as we hoped for this year. Too hot and many other reasons to get together too....At the Cafe cup we might just introduce this as a n-2 o/s class...I would rather see it in P O/S but that is what people are asking for.

I reccomend at least 7500 12C rated packes and would really like to see 10000 mah as a standard for sprint due to the amp rates. Some of us have seen some ballooned cells for no apparent reason but I personally have yet to experience any probs with mine.

Tapped out for now...yes pun included no charge(yet another pun)

 

[sjslhill]

There probably should be an area for an open class where voltage is the factor over cell count, I would agree.

However, you can't be running 10 classes with LiPoly packs and go off racing with packs charging by themselves, you will need someone in the pits monitoring the charging. You also better get some fire extinguishers that are rated for burning metals. It's not a matter of if, it's a matter of when a pack will burn.

thanks,

Steve

Hi Guys,
There's been many topics covering lipos use in FE and I'm thinking it's time to move forward.  My thought is to introduce a max voltage rule in the larger cell count classes (24/32) so that lipos or what ever can be used.  I DON't want to see them in the lower cell count classes yet.  I'll come right out and say it, anyone with the investment of these large boats will more than likely respect the nature of the beast.

The other thing I would like to see is being able to parallel 24/32 cell packs to allow for lower current draws and higher capacity matching the Lipos higher numbers.  I plan on using sub-c cells rather than Lipos and don't mind running against a lipo powered boat.

The other thing to talk about is running the bigger nitro size course, 330' straights and 35' turns.  Even on a single set of batteries it's easy to go the distance.

Okay guys, how about your thoughts?

Paul.

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[AlanN]

Steve,

Please this is a discussion of LiPo's and classes. I am fully aware of what you want to warn everyone about.

I have seen many cases of racers blowing up nicads and nimh's. I really wouldn't expect it any other way. Keep a bucket of sand near by but let's not get ultra paranoid about a battery that I guess over 50% of hang on ourselfs and stick next to our head everday.

Now about those classes....

 

[drobie]

If I can ever get out of work today pack my car and sleep while driving I might just make Chi town....looking grim so far. But I digress.

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What? You getting soft in your old age. It's 2.5 hours less than Mazo for cripes sake.

Get your butt in the car....oh wait...5 PM the night before...it is a little early for you to leave yet. h34r:

Sorry, back to the topic.

 

[Hydromaddicted]

Let's just slow down a little here.Classes with Lipo's?

I would'nt be the first to say, I would Love to try Lipo's

But?These Lipo's have'nt even been used at SAW yet and

Until someone has used 6,12,18,24,32cell voltage equivilents of Lipo's

with boats in a setting to push them to there absolute limits like nihm and nicad and we all have the results. Are'nt we just jumping the gun a little?

Let's sit back and experiment with Lipo for now and see just how big that explo :blink: sion might be

 

[AlanN]

OK Paul it's official...Forget it we can't do it noone can....we'll ruin the planet or blow off our hands....good thing we have such open minded people here to save us from ourselves. Gee I thought Paul and I were over 21 to...guess I'll have to check my drivers permit.

Oh well...we'll see you guys in the future....in our rear view mirrors!!!!!

Speaking of mirrors...better get on the road....

Just to avoid the 2 traffic jams Howies already been in.

This weekend I'm going to do alittle racing...don't have anymore time for discussing with closed minded sorts.

Oh and Hydro: IMO screw the SAW's that's not the point. Yeah lets start with the highest amp draw thats smart.

Paul and I just don't know anything. :wacko:

 

[eddieh]

Parallel packs? sounds ok, I think it would be cool to use 64 2200's instead of 32 3700"s or if you got a big enought boat 64 3800's would be neat too....LIPOS were already run at the nats in 1/8th...

 

[sjslhill]

Allan,

Did you read what I said? Did you skip this part? I agree with you.

"There probably should be an area for an open class where voltage is the factor over cell count, I would agree"

OK Paul it's official...Forget it we can't do it noone can....we'll ruin the planet or blow off our hands....good thing we have such open minded people here to save us from ourselves.  Gee I thought Paul and I were over 21 to...guess I'll have to check my drivers permit.

Oh well...we'll see you guys in the future....in our rear view mirrors!!!!!

Speaking of mirrors...better get on the road....

Just to avoid the 2 traffic jams Howies already been in.

This weekend I'm going to do alittle racing...don't have anymore time for discussing with closed minded sorts.

Oh and Hydro: IMO screw the SAW's that's not the point. Yeah lets start with the highest amp draw thats smart.

Paul and I just don't know anything. :wacko:

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[AlanN]

No Steve I wasn't really offended by your post. But last week was not a good one and I was a bit on edge.

What really got me was the next post about using them in the saws. Not very logical or reasonable to what was being proposed and I let my anger get the better of me. If no one ever tried something new or different where would we be?

I was raised by a father from the old school....don't think about why it won't work think about how it can.

 

[photohoward1]

Just an observation.....

Why would you parallel any size nickel based cell? 2200 or 3800? 64 average 3800 cells will cost you

about $400. and the weight will kill you.

Good matched cells could cost $750 and the weight would still kill you.

A good 10s3p lipo pack (7500 to 8000mh) would cost $800, give higher sustained voltage and

you could pull 80 to 90 amps safely.

So far we are only pulling 50 to 60 amps to get an 8th to go 55mph.

HEAVY BABY

 

[sjslhill]

I agree with you....go LiPo in this case.

thanks,

Steve

Just an observation.....
Why would you parallel any size nickel based cell?  2200 or 3800?  64 average 3800 cells will cost you

about $400. and the weight will kill you.

Good matched cells could cost $750 and the weight would still kill you.

A good 10s3p lipo pack (7500 to 8000mh) would cost $800, give higher sustained voltage and

you could pull 80 to 90 amps safely.

So far we are only pulling 50 to 60 amps to get an 8th to go 55mph.

HEAVY BABY

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[sjslhill]

As a matter of fact...Polyquest is looking into adding some of the 15-20C cells into some larger packs with taps to check single cell voltage ect. Astro is also working on a balancer device to work with the taps and the 109 charger, which can do 10 cell voltages

thanks,

Steve

 

[Paul Pachmayer]

Hey Guys,

I can say the weight is not a concern with 64 cells. I would also like to see someone pull 80 amps continuous out of a 7500 lipo pack.

I'm sticking with sub-cs right now and parallel packs in the right boat do work. There's also full Cs and full Ds that could be made to work also.

Use your imagination for a minute and think of what can be done.

Paul.

 

[Dennis Whitt]

Im with Paul.Tried to sneek Lipo into N2 offshore rules.About got my balls chopped and hooked up to Schultze charger.

I will be messing with 32 in paralel in 8th and maybe T offshore.

As far as changing the course size,I think an additional course would be eiser to get passed as it will not cut some clubs out that just dont have the room for a larger course.

A pond is hard enough to find let alone to have to give one up for a larger course.

Been there done that.

I would like to see a nitro sized course in addition to our regulation course.What say yee ???

 

[AlanN]

Totally new subject: larger course............but I fully agree.

Should start a new link but our current course IMO for ALL classes is too small.

I would love 330' of straight to let things wind out. I would love a bigger turn rad too.

What say at the CAFE CUP this yr we do a full blown course....for the 1/8 ers at least.

OK back to the LiPos ....was talking with Kelly and found out he is also using the 7500mah packs.....I thought he was using 10000mah. I really do think that if your gonna try the LiPo route to start with the 10000 at 10-12c rating first.

They weigh a little more than the neccesary amount of sub c's but the V is higher.

That is 6 sub c's compared to 2 cells of lipos.

 

[brooks93]

I will say this.. you will get longer run times with 2 sets of 64 but, you will not be faster then me in the same boat and setup with my 7500 or 10000 lipos.

I can pull 75amps without a problem. so 75 at 38 volts is 2800 watts you guy try and pull 100 amps and put it to a 2280 you will be buying a new motor. They are rated at 3000 watts and at that 100 amps you would be at 3850 watts. Sure you might get away with it a couple of times but, I bet you won't make a season with it at that draw.

I am only talking lehner motors here but, the 2280's have a pcb in the back of them. you draw to much and that board will pop.. Now a hi amp might handle it but, I think you will do more harm then good with that one.

now how much more watts will it take to push that extra 4 or 5 lbs through the water.. keep in mind my 7500's weight as much as 24 cells so you will have to push 5 to 6 more pounds then me. Or I could just run 2 sets of 10s6p lipos at 15000 mah. I could pull 6000 watts with out breaking a sweat batt wise anyway. Motor would just giggle as it grenaded into a million pieces

anyone want to take that challenge? 4 min enduro or 6 lap nitro course. Heck I will even give you a head start if you want to try it with D's

now I would say 2x32 in saws would make a HUGE difference but, again you motor is the weak link but, for a short burst you might be ok

I would also like to see someone pull 80 amps continuous out of a 7500 lipo pack.

Paul you already did.. my last run on the internats. the boat was running wet because of the glassy water I pulled 78amp cont.

 

[photohoward1]

It's called competion. I run a Chevy you run a Ford, Paul runs a Hemmi.

That's what makes it great run what you want and I will runwhat i want.

I still say weight is an issue but prove me wrong. PLEASE!!!!!

Go gettum guys.....

 

[T.S.Davis]

Technology

We can either find a way to embrace it and make it ours or it will run way from us.

The reality is that the rule book wont allow any out of the box thinking at this time. It's sub C 1.2v cells and that's it. It's a class thing. We have to get past THAT. That spec anchors us and keeps our creative juices in check. At least where cells are concerned.

ooooo, No Lipos. What comes after Lipo? There will be an "after" Lipo. Then what? Another couple of years to debate it's merrits before we can incorporate it?

Hoist anchor! What do you guys think of this idea?

As it's written we're stuck with Sub C's. BUT It's not a safety rule. It's in the FE section. It's there so that classes can be defined.

Any venue can allow LiPo if it so chooses. Parallel packs can be allowed also. All it takes is for some venues to allow it to prove that it can be done.

Dennis and I talked about allowing LiPo for MC6 in T Offshore but it being the NATS and the first official running of T offshore we figured we better stick to the book. We didn't even bother asking the club to vote on it.

Not many races left this year to allow the tech and kind of short notice too. What if we allow it at MC7 and CAFE for the 2006? It would require some careful attention to safety. Of course, MMEU would have to vote on it for MC7. Heck, not many venues are even running the big cell boats yet.

I personally would like to try 2 sets of GP2000 cells. 4/5 A cells for 4000mah. Should be able to yank 80 amps from them. Toss that in your 1/8 Scale. Simple and no extra safety concerns.

 

[Blake Hedges]

I personally would like to try 2 sets of GP2000 cells.  4/5 A cells for 4000mah.  Should be able to yank 80 amps from them.  Toss that in your 1/8 Scale.  Simple and no extra safety concerns.

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Don't waste your time, being the same diam. as the 2/3A cells I am guessing they cant handle much more current. I wouldn't expect anything more than 15-25A (max) from them. If you draw 80 amps you'l get like .6v a cell

Too small a diam. cell to handle what you want... the 2200's are the way to go