60C really?

[Finnster]

That's a pretty disappointing graph Brian, as well as a disappointing response from Austin. I guess I would be hard pressed to explain that as well, not that that is an excuse. That's unfortunate Austin has chosen to no longer participate in the discussion as the thread was for the most part was lively yet constructive. I must say such data and behavior does not inspire me to pay such a premium for Maxamps batteries. Such is the line between poor and foolish I guess.

For consideration Brian, here is a graph of my Neu 3S 2500 30C/60C batteries on my CRT.5. Please not that these were purchased in Jan 08, so comparable to the 1yr old models you have from MA.

As you can see, the batteries were holding approx 9.3V (3.1V/cell) at 85A draw (35C) and the highest output occurred towards the end of the pack where there was a 114A (~45C) discharge that yielded 8.9V. Please note that the pack was nearly empty, as the resting voltage was ~11.3V, so it represents a 2.4V (.8V/cell) drop. I'm not sure how a 60C discharge is determined however. This run was a considerable stress on the battery, but did not create any puffing or overheating.



To be fair, I don't know that I would advise running a pack so hard. I did run the pack even harder in some grass tests later on, managed to kill my lehner and the pack has seemed a bit flat ever since. Hence the need for accurate ratings. Theoretical burst ratings are fine and all, but do not help much in determining the performance or appropriateness of the battery for such an app.

Overall I highly recommend NeuEnergy lipos, and they can be had for really good prices if you care to look. They have been a bit more powerful than any zippies, but far better cell matched and constructed. You can buy nearly two Neu 4S 25C or 30C 5000 packs for the $250 the original MA pack is listed at.

Let me dig out a 4S zippy-h graph that replaced this system.

[Finnster]

Sorry I drew the graph so poorly, but basically we are looking at a max discharge of 90A (42C), and worst V drop to 13.3V (3.3V/cell), tho I don't think they are at the same time, but for now lets assume worst case and they do. These were purchased in May of 08, also last years chemistry and beyond their ratings. I still use these today. Very happy for $40.

[zeropointbug]

What also ridiculous is how they have runtime for their packs for the respective vehicle: (2) 2s 6500 packs in a BL e-revo will get 39 minutes runtime, ya, right.

Who else votes that Austin should cough up a pack or two for someone respected on this forum to test?

It will be the only thing that can put this thing to rest, is it not?

[_paralyzed_]

Give Lutach a pack, he'll test the bejeesus out of it and post vids.

[lutach]

Originally Posted by _paralyzed_

Give Lutach a pack, he'll test the bejeesus out of it and post vids.

I would have to pass....I would recommend a member that can be found in rcgroups.com (Sorry to mention another forum here), he goes by the username of everydayflyer and he has tested a lot of lipos.

[_paralyzed_]

Originally Posted by lutach

I would have to pass....I would recommend a member that can be found in rcgroups.com (Sorry to mention another forum here), he goes by the username of everydayflyer and he has tested a lot of lipos.

I just figured you had some amp hungry setups. It was a pipe dream anyway.....

[lutach]

Originally Posted by _paralyzed_

I just figured you had some amp hungry setups. It was a pipe dream anyway.....

I do have some amp hungry set ups, but after my 2 3S 3000mAh packs almost opened up, I will not take any chances, even if they do have better cells now.

[zeropointbug]

Originally Posted by lutach

I would have to pass....I would recommend a member that can be found in rcgroups.com (Sorry to mention another forum here), he goes by the username of everydayflyer and he has tested a lot of lipos.

YES! Everydayflyer is an AWESOME reviewer! He tested the TP 40C packs along side the G3's, very close in performance. With many many graphs and had all the cycling data based.

[lutach]

Originally Posted by zeropointbug

YES! Everydayflyer is an AWESOME reviewer! He tested the TP 40C packs along side the G3's, very close in performance. With many many graphs and had all the cycling data based.

He's the type of guy who will tell it like it is. If a cell or pack sucks, he'll say it, but if the pack is as good as it claims to be, the only one winning is the company that made that pack. That's why I like to test things over and over to make sure it performs not only good, but great. MA should do this as they have no control of manufacturing the cells and not all of them will be perfect.