Eagletree owners, I need info, please.
 

Hey guys,

In the last month, I've toasted about $600 worth of Lipo packs. Well, I didn't toast them all. Some died a miserable death as a result of some pretty bad crashes. After tonight, I'm down to two 4S packs and I need more.

I was going to get on Maxamps and order some batteries, but the 4S2P 6Ah packs are right at $200 (I'll killed one tonight) and my last two or three orders took over two weeks to get. Although I don't mind paying, I hate waiting.

I was looking around on ebay for some packs and came across truerc. He has some very reasonable prices on the 4S2P 8Ah packs. I think they're 10C packs with a constant of 80A and bursts of up to 120A. I also found a few others that were reasonably priced.

So...I'm looking for some data on the actual current draw of a Feigao 7XL with a Mamba Max ESC being run in a buggy with 14/46 gearing. Constants, peaks, whatever you can provide. I need to know if the truerc packs will do what I need them to do on the track without melting the heatshrink off.

Thanks.

I don't have #'s from a 7XL, but in general I can't see how any setup like this can cook a good lipo pack... like a 6000-8000mah from truerc or maxamps.

I have barely got mine warm even in the heat of summer. I think I temped a pack around 120... on a 90 day.

Currents will spike over 100A very briefly... only for like 1 second... then tapers off to 30-40 max under constant power. Average for the entire run will be @20A or less. I can see damaging a pack with excessive spikes, even though it never gets hot... but that shoul happen over time I believe... a slow death.

I have 2 3S2P 8000mah packs from TrueRC and ran them for the first time yesterday. I ran one for testing on a 10XL and 7020. I ran for a good 20 minutes and the pack never got hot, had AWESOME acceleration through the whole run, and aftewards, I checked the voltage and it only went from 12.4 to 11.69...

I have a 7XL and MMcombo, running maxamp 8000 and 5s i have seen over 120amps for like 2/20 of a second. Most of my runs are about three minutes and on blacktop with hard acceleration, so i doubt you'll see thos numbers

I have an Eagletree and a Mamba Max, but not the 7XL Feigao motor or the buggy. Sorry.

I've got graphs of my 7XL on 5S 4K packs of maxamps; they need a 2P for sure!

their 6K (2P 3000 cells) pack isn't capable of 20C continues. i've got graphs of these packs, and they are not capable of pushing out 100A

Yes, i am too interested to see Eagletree graphs from different setups. Interesting to see how all things work in real life.
I am to try do decide between 10c 5S 8Kmah TRUE RC or New 20c 5Kmah Maxamps.

With maxamps you will have top notch service. i don't know what truerc does?

TrueRC's customer service is right on par with the best.

I run the TrueRC 5s (2s + 3s) 8K packs in my Revo, Emaxx and XLB conversion with a bunch of diferent setups. Including a 1940/7 motor which is just as hot of a motor as the 7XL. The trucks are heavier than a buggy also so the amp draw should be even higher. I have never had a situation where the packs got more than even a little warm or had the LVC cut out before the pack dumped. I think you will be fine with the TrueRC 8K packs.

TrueRC has good service and usually ships quickly. Dan who runs the place is a good guy thats easy to work with also.

Just for reference, I just ordered 2 4s2p 8Ah TrueRc packs that I am going to run in a LSP with a Neu 1515 1/y (similar Kv to a 7xl). When they arrive I'll let you know how they run.

Bye:018:

The only conclusion that I can come to is that the 4S2P 6Ah packs that I got from maxamps suck big time. They don't even come close to being able to put out 20C, not if what you guys are telling me is true about the demands of my system. My track consists of mostly technical parts with lots of twists and turns, whoops and table tops, with two 160' straights. It really isn't anything that should put a strain on a true 6Ah 20C battery. When I run these packs fresh off of the charger and run them until the esc cuts out, they temp around 140-150, which tells me that I'm running them to their capability. After tonight's running, one of my packs won't even balance. It's been on the balancer for about four hours now. Cells 1, 3, and 4 are reading that they are discharging at the maximum rate of 300ma. I think that cell two might be dead. The pack isn't even two weeks old. I also have a 4S 4Ah pack and it's a joke. The first time I ran it, I couldn't even hold it when I tried to pull it out to switch packs.

We did order a 4S2P 8Ah pack, maybe that will fare better, but I'm going to have to re-do my battery tray and hold down to accomodate it. Unfortunately, I ordered the pack on Feb. 12, and it hasn't even shipped yet. I keep hearing all of the great stuff about maxamps' customer service, but I'm still waiting to see it. I mean, the guys are really nice on the phone. I've been recommending them to everyone that asks me about brushless and lipos. I think I'm going to stop doing that. Disappointing performance and some hard crashes have led me to seek a more cost efficient source of lipo packs.

Since it's clear to me that the maxamps packs are over rated, I think I'll try the truerc packs. I figure that a true 10C pack should be able to deliver all of the current that my setup could need.

Oddly enough, I have a "Hi-Po" Twenty 4400mAh pack. I probably paid too much for it at $160, but that thing kicks butt. I run it until the esc cuts out and it's barely warm. When I put it on the balancer, it balances almost immediately. With the Maxamps packs that I have, I usually have to wait for them to finish balancing EVERYTIME I charge them.

OK, I'll give truerc a try. I just hope that he ships his batteries a bit quicker than he ships his becs. Man, I don't mean to sound like a whiner, but all of this waiting is making getting setup a PITA. I'll tell you who has good customer service, it's RC Monster. Mike ships within a day or two of your order. Amain is quick too. If I order in the morning, it either ships the same day or the next morning.

AAngel, have you contacted Maxamps about the sub-par performance of these packs? If you haven't, I'd imagine they should be able to help you out.

I should do that, although one of the packs sustained some physical damage when it was thrown from a buggy and then someone T-boned that buggy with the battery hanging out. I guess I'll have to send them in and WAIT.

Of course, I could just order some packs from Truerc.

Contact Austin. He is familiar with the poor quality of the 6K packs, i contacted him about it as well.

If you are not happy with the batteries, you can sent them back.

Serum,

I contacted Austin at Maxamps and I told him what I was running and the trouble I was having. He didn't comment about the packs heating up, but only said that he wouldn't worry about the imbalance. He said, "They will go out of balance more if you are peaking at 120 amps. I would not worry about it."

I'm thinking that they are tired of hearing from me. I've been emailing about when my orders were going to ship, only after not having heard anything for over a week, and these 6K packs.

Well, maybe the 6K packs do suck, but they have some new 5K cells. I guess I'll try those.

I don't think a 20C continues pack should get out of ballance that bad. perhaps you can sent them back and trade them for the 5K cells.

I'd just get some 2P 8k Lipo's. I have them and they don't even heat up at all. They are the same temp when I put them in as when I take them out.

Given, I was running an HV-Maxx on them, but Novak says it pulls 150Amp Spikes (I talked to Charlie - this was when I went to purchase Lipo's, I wanted to make sure that the Lipo's were capable of providing for the system).

However, being rated at 160amps continuous, they should be plenty. Even if they aren't 20C and are actually something like 12C, they still provide 96 amps continuous, agian, plenty.

If you really want to go overboard, you can get the new 5K cells in a 2P pack...that should be overkill, but overkill works.

I'm planning on getting a LMT 1950/6, so I'll let you know how they handle it. It should be pulling similar amps I would think, but then again my truck is on the light side (~9 pounds).

the 150A spikes are when the wheels are blocked i guess. buy an eagletree, and you'll see the hvmaxx is a very 'tame' controller, current wise.

maxamps 6K packs drop bellow 2.75V on a 20C load for .2 seconds. so that's no way near a 20C continues. that's a 20C burst pack IMO

I have the same setup, BP. 1950/6 on 4S, MM esc.

How's it run Dafni - does the MM handle the motor ok?

I was gonna use a MM but many people doubted its capability to handle the 1950, especially one with such low turns.

Serum, just to clarify, I was saying the LMT would probably pull similar amps to AAngel's setup, not the HV. I know the HV doesn't pull that much, since I get like 40+ minute runtimes on the track with it and my 8k packs.

Serum,

Austin didn't even come close to suggesting anything like exchanging the packs. As I said above, he said that I just shouldn't worry about it. I don't know why I keep feeling the inner compulsion to continue buying from Maxamps, but I do. I'm going to give the 5Ah cells a try. The 4Ah cells in a 2P configuration make my buggy too heavy for my taste. Our track is on the tecnical side and the extra weight makes the buggy harder to handle. Even the 6Ah packs were a bit big for my taste.

As far as exchanging the packs goes, I don't think I can in any event. Both of the 6Ah packs that I have suffered some damage as a result of crashes and the battery hold downs not doing their job. Boy, R&D is expensive.

What I'll probably do this time is just order some bare cells. That way I can assemble them myself and if I have a problem, I can just replace cells. Working on the welded packs is a PITA, when you have to do repairs.

BTW, has anyone had any experience with the 10Ah cells? I want to get a couple of those in 4S packs to run in my Monster GT conversion. Lots of space for batteries there.

Get them in a pack, (it's easier to point a finger when they are dropping too much in voltage) and ask Austin if he wants to replace them if they are not up the task.

You haven't got an eagletree?

You can forward this thread to him, he always has been very reasonable to me. If the cells don't do as advertised, something must be wrong, right?