I am wrong about MaxAmps.

[aqwut]

Thank You Austin, TBH..
You are absolutely correct!! As a company grows, more people will lash at you. But after your explanation of the tronics cells, I understand. And I'm aware that LiPo cell technology are always improving. It doesn't take much to calm down a situation. I personally think Jason should just quit calling people a Liar. I have never thought about never buying MaxAmps packs again, until Jason replied to my post in the manner which he did. Maybe it's a good thing that he has a lot of pride in the MaxAmps product, but you can't just push this thought or opinion to everyone who has a difference of opinion. Thank you for the explanation, and especially the graphs...

[DrKnow65]

Is it possible i've hit 250amps with this rig?

Specifically a Team academy SBV2-Pro 1/10 4wd buggy, MM/5700Kv, 5000mah 3S, 15/86 gears (around 78mph on BrianG's speed calc)

I would think the tabs would have to conduct the burst rating of the pack. I mean the sustained rating is 150amps, and the continuous is 100...

So far this is the best arguement for high voltage I have seen. No matter how good the cell is, if the tabs can't handle the load, better run more volts and less amps.

[johnrobholmes]

Awesome! Graphs! It might be my monitor, but could you blow them up a bit so I can read the numbers? Any temperature data and 1c, 10c, 15C graphs for comparison would be nice too. Especially temperature that is needed to duplicate these rates.


It is really nice to see some data finally, bravo Austin.

[johnrobholmes]

Looking at the graphs a bit harder here, it seems that the average voltage is around 3.6v/cell. Wouldn't this indicate that running them at 20C is not the max continuous rating, and that they could be pushed quite a bit harder? But at the bottom of the 3.2a/h cell graph it shows 12a/h on the discharge?


edit: my eyes hurt, I will wait for you to enlarge them before I try to read any more

[lincpimp]

Originally Posted by DrKnow65

Is it possible i've hit 250amps with this rig?

Specifically a Team academy SBV2-Pro 1/10 4wd buggy, MM/5700Kv, 5000mah 3S, 15/86 gears (around 78mph on BrianG's speed calc)

I would think the tabs would have to conduct the burst rating of the pack. I mean the sustained rating is 150amps, and the continuous is 100...

So far this is the best arguement for high voltage I have seen. No matter how good the cell is, if the tabs can't handle the load, better run more volts and less amps.

Sike and I came to the conclusion that there is no way that the thin little tabs could hadle the spec discharge numbers, just not going to happen. High voltage is a much better way to go. My 8s savages with the 14xl feigao runs 3600 12c poly rc packs (around 45 amps cont) and has no issues. Motor gets to around 140 and stays there for a 30min run. The 60 amp esc barley gets warm, maybe 110, and the batteries are around 105 when the run is done. It is a heavy truck, and has plenty of power, more than my 7xl 4s revo.

[DrKnow65]

I'm with you there JRH, I put it on photoshop 11 and blew it up, cleared it up as best I could, and still can't make out the numbers well enough.

Linc, It's just hard to fit HV into this little buggy. I need to get a better understanding of how to calculate the wattage different KV motors pull at different voltages. I do have a 2300KV ammo motor that I turned the shaft down to 3.2mm and use in this buggy to make it more raceable on the micro track at the nearest hobby shop. I guess I could get a 5S pack to get the performance back, but can I find one that will give me similar performance to the 5700/3S/5000mah and not weigh a ton?

Sorry for the small graphs...

There are larger versions here

http://www.nitrokillers.com/forumdisplay.php?f=117

John-I am not seeing the 12ah that you are referring to.

The tabs that we use are copper, not nickel. Copper is 10X more conductive and our copper tabs are very thick. Twice as thick as most the manufacturers I have seen. They can handle those very high amp draws in bursts. I think I have an eagle tree showing bursts in the 250 amp range. I will see what I can dig up. Very few setups are running in this range.

At 20C average, a pack will last 3 minutes. Most guys will set up for a longer run time than that unless they are drag racing or doing speed runs on boats.

With the expanded CBA we were able to do burst at 120 amps. I will try and dig them out or get them tested again.

I do agree that high voltage is a sweet way to go if it will fit.

-Austin

[johnrobholmes]

Can't see them, I have been IP banned from your site unfortunately.

Did you collect any temp data?

Oh yes. There is that little issue:)

The temps were all between 85-90 degrees at the end of the discharge. Keep in mind that this is without shrink wrap on the cells so the temps would be higher in a pack format but no where near the 140 degree max.

I will try and get the high def versions of these posted here also so you don't have to squint.

I will also see about taking care of your banned IP issue:)

[Serum]

@ austin;

Jason swapped the graphs; he swapped the 4200 with the 3200.

are these graphs provided by the producer are are these own measurements?

And can you share what equipment was used for testing?

[Sammus]

There is a 12Ah there.. the scale down the bottom on both graphs goes to 10x the battery capacity. Instead of 4.2Ah its 42Ah... it even says it on the side that it was measured at 32Ah, or 40Ah... is that a 10p pack or something?

[Serum]

my guess it's just a scale error, i think a bug in the software or such;

The capacity and voltage are setup correctly; I assume the software automatically scales with the variables you can put down in these fields.

[Sammus]

Maybe its a 1s10p pack and thats why the voltage is so good under load :)

I kid I kid...

[Serum]

That's bellow the belt mate! Austin is doing his best to help here!

[Sammus]

Bahaha I'm just a stirrer, I tried to make the sarcasm obvious with the second line :P To Austin or any one else: just kidding, please don't take me seriously :P I was just poking fun at the haters :)