Say it ain't so, PLEASE! Atomik Stupidity!

[ray schrauwen]

LOL....

[properchopper]

Tony got the Point.
I remember a tech-discussion in germany regarding cells and oval rules half a year ago. There was stated, that with the extreme sensitivity of the current Generations (6,6Ah Aspec, etc.) at and above 60° watercooling could be an effective way to drive the whole capacity in a race without overheating/damaging the cells.

If it makes really sense in practice and how to get it ideally integrated (the temp dramatically rises in the end of capacity, for 80% of running time you do not want to cool your cells) is another discussion

Since this discussion rolls on I'd like to re-state my original point : (Like I told my Ex on our honeymoon):
"It's all how you look at it". If we're performance-sport or sprint racing, the setups are usually configured to not unduly tax the electronics. We know fairly accurately what our runtimes are and use enough mah capacity to allow some headroom. No need to cool the packs.

For the entry-level Atomic/Venom casual FE'er, it seems(from posts I seem to recall reading), extended runtimes are desired and THAT's where the batteries end up getting destructively hot and could benefit from cooling. And as my buddy Ralf alluded to, European racing employs much longer heats than here (Offshore excluded but...) and "..watercooling could be an effective way to drive the whole capacity in a race without overheating/damaging the cells."

I'm not defending nor criticizing the issue of pack cooling, only that by thinking outside our often narrow-minded frame of reference we can see points made from other directions.

[TheShaughnessy]

I tried to water cool nihm cells when I was starting out. Seemed like a good idea since they kept melting the shrink wrap.

[Ralf]

Why opening a ton of parallel topics?

Many of us use setups that don't put the batts in this kind of peril. Doing so does not guarantee a win.

Did i described that?

There are far better cells for the same $$ than A-spec.

They were an example for the generation of lipos.

So to make a battery cooler effective you may have to have a 3rd channel switch for a valve to incorporate the cells into the cooling cct. or have it's own separate system. Seems like if you just backed off your setup, you would not require this complication.

Another discussion for personal feels.

I explained a discussion which was going on because of the heat sensitivity and where it is coming from.
I do not care of that stuff, but the technical background makes it interesting.

"It's all how you look at it"

[Brushless55]

So some like to pre warm their packs and some like H2O cooling for their packs

[kfxguy]

Well fellas just think if this cooling of packs was applied to good batteries....then you might be on to something! Wait....if you actually have good batteries they don't need cooling muhahahaha!





I know I know...I got jokes...true story tho

[olwarbirds]

Ray you can PM me the results of your testing pls ... we will keep it ... this is a good smile type thread.... Im going to make a thermostatically controlled sheath to put my lipos in, use water cooling and esc and motor heat, this will keep the packs at a constant peak temp of performance. So look out next yr

[Doby]

I velcro my lipos to the deck...provides water and air cooling. Only after preheating them to 125.7F, the optimal temp for maximum discharge.

[keithbradley]

Ready for the next laugh, I had previously mentioned that I had asked on their site how could they be selling a watercooled lipo but it not be warranted against water damage...well they did finally respond
"A: Hello DJ,
These batteries are designed to be ran in conjunction with your boats contained cooling system. The battery is to be used inside of a dry boat hull. You will run this water-cooled battery inline with all of your other water-cooled components.
Thank you "
Now talk about not actually answering the question ..... Happy Turkey day guys

Forgive my ignorance (or perhaps lack of comprehension), but I'm not sure what you see wrong with their statement. It seems like a pretty reasonable answer to me. Many ESCs are water cooled and not warrantied in the event of water damage. I don't see where this is any different.

I also think that while this may be a gimmick for the most part, at least they tried something (although I remember maxamps doing this a couple years ago, resulting in a similar thread). The majority of lipo companies do little more than slap their sticker on a pack that someone else made and call it a day. There is nothing wrong with those companies, but I applaud the companies who go a little off the beaten path and try to offer something different.

I don't think this idea is as silly as many of you think it is, either. I think liquid cooled cells are a possibility, likely a probability in the near future. I don't know if they will become commonplace in models but in larger machines that need to run for longer periods of time it seems pretty logical.

[keithbradley]

So some like to pre warm their packs and some like H2O cooling for their packs

The ideal situation would be both, right? "Moderation" of temperature change...Lower the delta T between the start and the end of the run.

[NativePaul]

I saw a few battery coolers at the Naviga worlds last year, water cooled plates to slip between cells in a pack allowing a slightly deeper discharge with similar (not quite death inducing) end of run temperatures to allow a little more average power during the race. The theory seems sound to me, but whether the little extra power outweighs the extra weight of the coolers is debatable, so until they are popular enough here for me to get a good sample of numbers from I will keep things simple and cheap and stick with my existing cutoff voltages and un-cooled cells.

With the aid of datalogging the temperature of the water motor, esc and the batteries it may be feasible to restrict the water flow enough to both heat and cool the LiPos, it is far too much time and effort for me to take on for something that may or may not be worth its weight, but I bet someone successfully does and I see the results in the next few years.

Many of us use setups that don't put the batts in this kind of peril. Doing so does not guarantee a win.

Same here Ray, I like my cells to last 2 seasons, so I don't fully empty them, but if I left the common 20% in the cells it would guarantee never getting a win.

There are far better cells for the same $$ than A-spec.

I'm sure that is correct for the racing that you do, but that is not the case for Naviga racing with our 280g/560g weight limit, there are better cells available from Redzone and Tenshock but they are more expensive, or there are competitive alternatives from ETTI, Desire, and Victory Batteries, but I believe them to be the same cells and you still pay more.

European racing employs much longer heats than here (Offshore excluded but...)

Propperchopper, Offshore isn't really an exception, we race for 6 minutes in Naviga, which is much closer than with your sprints, but we still need half as much runtime again. We also need to do it on only 560g (1lb 3.75oz) of battery for our equivalent of "P". What do the periods allude to, do some of your guys have trouble with hot cells puffing in Offshore too? What does a typical P offshore pack weigh? I guess most people run 2p? You limit capacity not weight over there right, what is it, are most folks near the capacity limit?

[Make-a-Wake]

Apparently Maxamps was the pioneer of these water-cooled morphs.......

http://www.rccaraction.com/blog/2011...battery-packs/

[Make-a-Wake]

OMG, check out the only comment on the Maxamps review thread I posted above...............its at the bottom when you scroll down, but here it is...........

"How about a pump to deflate the packs when then puff ?"


Thats Hilarious, the only comment on their "new" product

[properchopper]

"......Propperchopper, Offshore isn't really an exception, we race for 6 minutes in Naviga, which is much closer than with your sprints, but we still need half as much runtime again. We also need to do it on only 560g (1lb 3.75oz) of battery for our equivalent of "P". What do the periods allude to, do some of your guys have trouble with hot cells puffing in Offshore too? What does a typical P offshore pack weigh? I guess most people run 2p? You limit capacity not weight over there right, what is it, are most folks near the capacity limit? ...."

Paul, As far as the P class goes (which is where I mostly compete except for P-Ltd) ; A mill + 6-Lap heat on the 1/6 mile oval usually runs @ 2 1/2 minutes (barring penalty laps). Offshore is a 30 second full mill + 4 minutes.

In NAMBA P class the mah limit is 10,000. 4S2P is usually the norm. A single 4S2P weighs @ 540g.

I stopped entering P-Offshore with my P-Oval rigged Mono 'cause I worried that I'd draw my packs down too low.

The last time I entered P-Offshore I had a way propped down (to conserve mah) dual rudder Mean Machine which wasn't competitive.

The Ltd Offshore class uses motors drawing maybe 80A / 100A max so with 10Kmah on board no worries.

[ray schrauwen]

I saw a few battery coolers at the Naviga worlds last year, water cooled plates to slip between cells in a pack allowing a slightly deeper discharge with similar (not quite death inducing) end of run temperatures to allow a little more average power during the race. The theory seems sound to me, but whether the little extra power outweighs the extra weight of the coolers is debatable, so until they are popular enough here for me to get a good sample of numbers from I will keep things simple and cheap and stick with my existing cutoff voltages and un-cooled cells.

So I am seeing it this way. Naviga rules have weight limits as I knew already so, add weight with coolers to your already setup boat that may be at max weight already, therefore you have to trim weight somewhere else...

Does anyone else see this as tail chasing? I'm not trying to be rude or condescending but, give and take is the quandary. Where do you take weight away from, cells, motor, hull, hardware?? I'm sure it's only a few grams or it could be more depending on the design.

What is in there anyway, just an aluminum plate or a copper plate or a water filling type like the ones hobby king sells?

Did Max Amps and or Atomik test the efficacy of the water plates and is there testing data available?

Why should the public be the guinea pig to find out results if they are effective and useful? What do they (Atomik & MaxAmps) know that you or I missed?

I find this slightly humorous:

This system offer lower temps and higher performance in the Traxxas Spartan

We all know how the Spartan started out, motors and esc's burning up. Before they hit the stores I predicted that their original system would melt down and I was right. I'm not right about everything, hell, I'm wrong a lot! Lets see how this stuff plays out.

Max Amps also states that you will get 26 minutes run time in a Spartan with these 6500 cells in series for 14.8v nominal. I think that's maxing out at 35 amps for 24 minutes by some quick math in my head but, again, I can be wrong.

[Brushless55]

We all know how the Spartan started out, motors and esc's burning up. Before they hit the stores I predicted that their original system would melt down and I was right. I'm not right about everything, hell, I'm wrong a lot! Lets see how this stuff plays out.

Max Amps also states that you will get 26 minutes run time in a Spartan with these 6500 cells in series for 14.8v nominal. I think that's maxing out at 35 amps for 24 minutes by some quick math in my head but, again, I can be wrong.

to run those packs for 24min to the 20% rule means, that boat is only pulling 12amps
man that sucker must really fly with 178watts

[NativePaul]

So I am seeing it this way. Naviga rules have weight limits as I knew already so, add weight with coolers to your already setup boat that may be at max weight already, therefore you have to trim weight somewhere else...

Does anyone else see this as tail chasing? I'm not trying to be rude or condescending but, give and take is the quandary. Where do you take weight away from, cells, motor, hull, hardware?? I'm sure it's only a few grams or it could be more depending on the design.

What is in there anyway, just an aluminum plate or a copper plate or a water filling type like the ones hobby king sells?

Naviga do have some maximum boat weights for the smaller speed and steering classes, but they are not endurance events so battery cooling will be of no use to them.

I was thinking of the oval and Eco classes, none of which have maximum boat weight limits, the maximum weight limits we have for these classes are just for the battery, (Mini=110g, Mono/Hydro1 and Eco=280g, Mono/Hydro2=560g) including anything fixed to them ie wires, heat shrink, connectors, velcro etc. By having separate cooling plates plumbed into the boat that freely slide in and out of the cells they are part of the boat and are not included in the battery weight.

It should not be possible to save the weight of the cooling plates as the motor, hull, and hardware should already be as light as is practical to do their jobs reliably. As the boat will be heavier with the plates you will need to discharge the LiPos deeper to get the extra power needed overcome the increased wetted area, there will be a threshhold where you are swapping the acceleration and nimbleness of a light boat for the rough water capability of a heavier boat but maintaining the same speed, and I suspect if it allows you to reliably get any more power out of the cells than that it will be an advantage.

The coolers I saw were aluminium alloy or brass plates, with a tube soldered, glued or one piece machined in/on to one or both sides, they have to be quite thin to fit between the cells in a standard battery, I would guess they were between .75-1mm thick, If you wanted to use a water in a cavity type cooler (which would be more effective for cooling), not only would you have to rebuild all your batteries with enough slack in the tabs to fit the thicker coolers in but you would have to design new hulls with space to fit the thicker batteries in.

[ray schrauwen]

They state 32+ mph.....

to run those packs for 24min to the 20% rule means, that boat is only pulling 12amps
man that sucker must really fly with 178watts

Paul, thanks for educating me. Sorry I was a bit un-read on the Naviga classes you were referring to.

[Spartanator]

Can't I just make the lipo be a ride pad??? Lol

Haha, 26 minutes in a Spartan... Maybe 26-20=6!

[ray schrauwen]

I thought of doing that once...