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Lipos getting hot
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Klausen
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Lipos getting hot - 07.27.2009, 08:52 AM

I have 2 x 7,4v. Maxamps 6000 mah. lipos

I have never really driven them out to their full potential, and I have never been near the cutoff point.

Then today I ran them in my Brushless E-revo, for around 15 minutes mixed driving, with some speedruns too. After I stopped they were really hot ( It was possible to hold them in my hand though), but they were kind of like "floating" and a bit blowed up.

My E-revo have the MMM set-up, and the esc´s fan wasn´t even activated.

Do you know what have happened, and are my lipos ruined?
   
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suicideneil
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07.27.2009, 09:12 AM

Maxamps = fail. Older Maxamps 6000mah packs (3000mah cells in parallel inside) = even bigger fail.

Thats all you need to know, seriously. They are well known to be poor cells that cant handle high current draw, like the MMM system requires. Since they have now exceded 120*F and have puffed, you should dispose of them by cutting off the wires, and submerging them in a plastic bucket of salty water for a few days, to drain them down to 0 volts.

Or you can hook them upto a power supply putting out 10amps, stand well back, and enjoy the fireworks...
   
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zeropointbug
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07.27.2009, 10:48 AM

Yeah, you pretty much have the textbook MA pack failure... the 6000 packs were baaaad! Just throw them in the F!@#$N garbage.

On a serious note, dispose of them how Niel said.

And go get some Hyperion G3 packs, or if you want something cheaper, the Zippy flightmax packs.


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Klausen
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07.30.2009, 08:15 AM

Thanks for the info. Obviously I placed my money wrong when choosing these packs :o(

But now I have balanced them and charged them. Fortunately they still work fine, but I think I will use them in a smaller car, than the E-revo.
   
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nitrostarter
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07.30.2009, 12:02 PM

Yeah, they should be ok in a smaller car. E-Revo's demand a higher quality pack that than, something that can dish out some Amperage.


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jzemaxx
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07.30.2009, 02:12 PM

Its hot cause their C rating is WAY over inflated. They can't sustain the amp draw.


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lincpimp
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07.30.2009, 03:46 PM

If your lipos shrink back down after sitting they are still ok to use, but I would not suggest using them in a higher amp draw situation again. Anytime a lipo puffs up, some of the internal chemicals have out gassed, so you will have either diminished capacity, performance, or both. The 6000 MA packs are good for about 70amps cont, and maybe 100amps burst. They are great packs for a 10th scale 2wd truck or buggy, and make a killer roto start/ez start pack. That is what I used to use my 6000 MA packs for. As far as running a MMM/2200 combo on 4s, you will need a better lipo, like the enerland 5000 25c series, or the new hyperion g3 lipos.
   
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redshift
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07.30.2009, 08:13 PM

Deja Vu... I feel your pain, same thing happened to mine over the winter.... the 6000's were/are complete utter trash.

Look into the Hyperion Swift Classic 4000 packs, Mike sells them- http://www.rc-monster.com/proddetail.php?prod=HP-SW0001 The 80 amp rating looks unimpressive- do not be afraid. All you need to do is clip the Tamiya connector off and use a high current connector, they only have those so they will work with the older cars.

They will make your MA packs seem like toys, they will toss my 14+ pound rig around for 18- 20 minutes and come out lukewarm. The price is also a tremendous bargain- these packs are twice what I expected- I am sold on Hyperion for the foreseeable future- seriously I won't even look at Flightpower anymore because these 4000s are that much stronger than my 2S FP Evo25 4900s were- I sold those.

Look at the Hyperions- they are phenomenal!

Last edited by redshift; 07.30.2009 at 08:52 PM.
   
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Klausen
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07.31.2009, 08:17 AM

How about the Zippy 30 c 5000 mah. packs. How are they compared to the Hyperions?
   
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