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-   -   Rustler VXL Trailer (https://www.rc-monster.com/forum/showthread.php?t=22319)

magman 07.16.2009 06:21 PM

Nice vid...especially like the end when the truck is sliding on it's roof for what seems like forever:lol:

Byte 07.17.2009 07:14 AM

Quote:

Originally Posted by magman (Post 305095)
Nice vid...especially like the end when the truck is sliding on it's roof for what seems like forever:lol:

Thank you. My whole body looks like shit now because the car slided to oft on his back :lol:

PBO 07.18.2009 07:48 PM

My stock Rustler did it's highest speed (50.1 mph GPS) on it's roof!

Very nice vid

Byte 07.29.2009 06:39 PM

Well, I just drove with my Rustler. Same setup as in the video. And now I know my Rhino can deliver 60C peak! This is incredible, isn't it? And what about the pack voltage? The minimum is 8.87, is this critical or is it good? And why doesn't my LiPo cutoff comes in? It's set to 3.0V so that would be 3 x 3.0 = 9V and the LiPo got under 9V?

Anyway:

http://img139.imageshack.us/img139/7913/rustleret.jpg

skellyo 07.29.2009 07:27 PM

Quote:

Originally Posted by Byte (Post 308520)
Well, I just drove with my Rustler. Same setup as in the video. And now I know my Rhino can deliver 60C peak! This is incredible, isn't it? And what about the pack voltage? The minimum is 8.87, is this critical or is it good? And why doesn't my LiPo cutoff comes in? It's set to 3.0V so that would be 3 x 3.0 = 9V and the LiPo got under 9V?

Your packs are definitely not 60C, not even a 60C burst. If it were a 60C burst pack, your voltage would not drop below 3V/cell at that load level. 8.87 is definitely not healthy for that pack.

From what I see, you're pushing the very maximum limits of that pack and will be lucky if they last very long before puffing, especially when you start dipping below 3V/cell.

suicideneil 07.29.2009 08:11 PM

I would need to see seperate volt,watts and amps graphs to give an accurate C rating judgement (the overlaid graphes obscure the voltage lines when its dipping low).

On the LVC issue, it seems it just isnt sensitive enough- I would raise ot to 3.2v per cell, maybe even 3.4v.

Byte 07.30.2009 05:58 AM

I was just looking at the graph again. But the LiPo only got 2 times under 9 volt. And I was driving in grass hill up and down. Maybe because of going full throttle up hill got the LiPo beneed 3.0V/cell?

http://img70.imageshack.us/img70/7913/rustleret.jpg
http://img90.imageshack.us/img90/7913/rustleret.jpg

As you see it sometimes get over 80A and the voltage doesn't drop below 3.0V/cell

shaunjohnson 07.30.2009 06:57 AM

i dunno!
i'd say it's doin a pretty darn good job!!:party:
yeah so it's pushing the limits...but it weighs what? fark all and i bet it was super cheap too:party::yipi:
looks like a heap of fun, the worse thing i did for my rustler is use the 3s 8000m,ah packs, too heavy but cant argue with 1 hour runtime under race conditions (that's how i got 2nd in the MT unlimited 1 hour mains :rofl:, all the nitro's broke down/ran dry)

Byte 07.30.2009 07:38 AM

Quote:

Originally Posted by shaunjohnson (Post 308702)
i dunno!
i'd say it's doin a pretty darn good job!!:party:
yeah so it's pushing the limits...but it weighs what? fark all and i bet it was super cheap too:party::yipi:
looks like a heap of fun, the worse thing i did for my rustler is use the 3s 8000m,ah packs, too heavy but cant argue with 1 hour runtime under race conditions (that's how i got 2nd in the MT unlimited 1 hour mains :rofl:, all the nitro's broke down/ran dry)

What is bad/normal/good for a LiPo? A voltage drop under 3V/cell is bad? Exactly 3V/cell is normal and 3+V/cell is good?
It weights... well... yes, nothing :lol: It costed 15 dollar!
And yes it jumps like hell because it's awesome light! And I get a runtime of 15+ minutes. As you see in the graph I was at 13:30 minutes or something and I used 1050mAh of the capacity.

Wow, 1 hour... That's damn long, but I still like my 15+ minutes and super light car :) But for a 1 hour race that's perfect ofcourse!

skellyo 07.30.2009 09:00 AM

Quote:

Originally Posted by Byte (Post 308706)
What is bad/normal/good for a LiPo? A voltage drop under 3V/cell is bad? Exactly 3V/cell is normal and 3+V/cell is good?
It weights... well... yes, nothing :lol: It costed 15 dollar!
And yes it jumps like hell because it's awesome light! And I get a runtime of 15+ minutes. As you see in the graph I was at 13:30 minutes or something and I used 1050mAh of the capacity.

Going under 3.0V/cell on a Lipo is not good at all. You'll shorten the life of the battery at a minimum. While you may be getting away with less battery, you're certainly not promoting a long lifespan of the battery running the way you are. IMO, it's just not safe to run a battery in application where it will be routinely subjected to currents beyond it's burst rating.


Also, IMO, if the Lipo was an optimum choice for the application, it should not drop consistently below 3.5V/cell until nearing the end of the run.

suicideneil 07.30.2009 02:07 PM

~9.7v @ 80amps = 60c.. ermmm.

It is actually putting out 60c bursts- the voltage stays around 3.3v per cell, the current being drawn is up around 75-80amps, so 80amps / 1.35amps (1350mah pack remember) = 59.xxx. If you go by the heavier bursts, then its putting out around 40-50c bursts.

The weird thing is that some of the smaller bursts around 65amps are what cause the voltage to drop down to around 3v per cell. That I dont quite understand myself, could do with some more expert input & interpretation of the graphes.

It is still very impressive for such a small pack though, would love to see how a larger version of the same cell will perform. :yes:

skellyo 07.30.2009 02:43 PM

Quote:

Originally Posted by suicideneil (Post 308779)
~9.7v @ 80amps = 60c.. ermmm.

It is actually putting out 60c bursts- the voltage stays around 3.3v per cell, the current being drawn is up around 75-80amps, so 80amps / 1.35amps (1350mah pack remember) = 59.xxx. If you go by the heavier bursts, then its putting out around 40-50c bursts.

I'm not sure where you see it staying at or above 9.9V at 70+A? It's routinely under 9.9V at most any current over 40A.

I'm not saying it's a crappy pack by any means. I just think it's way overtaxed in that application. Hitting peaks of 40C+ on every trigger pull is not a safe use of a Lipo, period. I stand by my comments that this pack is not being used safely and if it goes poof, it's absolutely the fault of the user for putting it in the wrong application.

suicideneil 07.30.2009 02:53 PM

Its around the 375 second mark- but that is a fairly isolated incident. It does drop down around 9v with most 50amp bursts, but thats the thing- it isnt consistent. One 70amps burst drops it down to 9.7v, another a few minutes later drags it down much lower...

I would like to see a couple of these pacsk in parallel, that would boulster the performance for sure.

skellyo 07.30.2009 03:44 PM

Quote:

Originally Posted by suicideneil (Post 308791)
Its around the 375 second mark- but that is a fairly isolated incident. It does drop down around 9v with most 50amp bursts, but thats the thing- it isnt consistent. One 70amps burst drops it down to 9.7v, another a few minutes later drags it down much lower...

I would like to see a couple of these pacsk in parallel, that would boulster the performance for sure.

Oh, no doubt. I'd bet that if the capacity of this pack was doubled, the voltage would be maintained to 3.5V+/cell for just about any peaks.

RCShocker 07.30.2009 04:50 PM

Quote:

Originally Posted by Byte (Post 304947)
(It's a bit short, but it's a Trailer)


I say it's a TEASER .......:yes:


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