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Old 04-01-2013, 04:32 PM   #1
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Default Who charging 20+ amps or more now??

There's new lipo battery technology.

Who else is charging higher then 1C?
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Old 04-01-2013, 04:38 PM   #2
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I usually charge about 8 amps. I'm not running oval, so heating them up doesn't do much anything noticeable.
I do have a GFX and a Powerlab 8, so I have been tempted. I've heard high amp charging will knock the "shine" off a new battery sooner.
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Old 04-01-2013, 04:40 PM   #3
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10amps everywhere I run.
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Old 04-01-2013, 04:42 PM   #4
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Quote:
Originally Posted by MC112b View Post
I usually charge about 8 amps. I'm not running oval, so heating them up doesn't do much anything noticeable.
I do have a GFX and a Powerlab 8, so I have been tempted. I've heard high amp charging will knock the "shine" off a new battery sooner.
That and I'm a tight-azz. So the thought of shortening the cycle life of a battery to save a few minutes doesn't make much sense. I never have trouble getting batteries charged.
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Old 04-01-2013, 04:51 PM   #5
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Our rules do not allow us to charge at a rate higher than 1C and besides, i can really not see any need to charge at such high rates either. It is not like our race schedules demand a fresh pack every 10 minutes.

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3.11 Must be charged using a Li-Po capable charger only at a maximum rate of 1C.
The packs i use to bash with friends i charge at 10A which is the maximum rate of my charger, purely for keeping the car moving.
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Old 04-01-2013, 05:05 PM   #6
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Interesting..

I charged at 3C+ a two cell lipo pack and notice my internal resistance shot down really low and the pack that was over two years old.

Incredible punch and the lipo had a higher voltage through the discharge.
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Old 04-01-2013, 05:09 PM   #7
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I charge at 12A most of the time. 18-20A if I forgot to hit start, which occasionally happens. It's been at least a year and a half since I last charged at only 1C.
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Old 04-01-2013, 05:16 PM   #8
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I usually charge my 2s and 4s car packs at 10a. I don't see a need to go any higher than that. They charge up in about 15 minutes. Charge time has a lot to do with how the charger balances as well. The high end chargers will balance cells throught balance port by charging low cells instead of draining high cells like most chargers do. My charger balances by charging the low cells through the balance port at up to 2 amps. This really improves charge times. The cheaper 20amp chargers don't do this.
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Old 04-01-2013, 07:03 PM   #9
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If you want to charge at 20 amps, i strongly feel you should have a quality charger. A Powerlab or GFX will have the accuracy to do it safely. A $40 knock off out of china may not do what you want.
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Old 04-01-2013, 07:16 PM   #10
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If I'm in a big hurry, I'll charge at 20a, but usually it's 10a on an iCharger 206b.
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Old 04-01-2013, 07:34 PM   #11
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7 amps is the best compromise out there.... You don't want to keep pushing your equipment and batteries to their limits, or else you'll cause a fire !!!!
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Old 04-02-2013, 09:58 AM   #12
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Quote:
Originally Posted by Mr RCTech View Post
Interesting..

I charged at 3C+ a two cell lipo pack and notice my internal resistance shot down really low and the pack that was over two years old.

Incredible punch and the lipo had a higher voltage through the discharge.
Interesting indeed......Immediately raises some questions for me.

What amp rate have you been charging the same pack previously?

How old and what brand lipo was it?

What are you using to measure the IR drop (Turbo 30, etc)?

Thanks for your input.
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Old 04-02-2013, 11:16 AM   #13
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Oh boy here we go again.

I had hoped that Lipo would eliminate all the battery craziness that we had through the years with sub-C's. Guess not.
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Old 04-02-2013, 11:49 AM   #14
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The ONLY thing that charging at higher amps will do is: Charge the battery faster, cut down on the life of the pack (from 300 cycles to 200 cycles maybe all speculation), and it will warm the pack internally which will decrease IR and increase voltage. But with all the big races checking battery temp it will not help as it wont pass tech.

The heat is the only reason it increases the voltage and lowers IR. If you let the pack cool to room temp and check it it will be the same as if you charged it at 5 amps. I have yet to see a charger that has any special voodoo built in that will charge and make a battery faster without using heat.

Ive been charging at 40 amps since December with the ICharger Duo 4010 came out. I raced every week all the way up till the birds. I only keep two packs to my name at a time. I practice and race on those two packs every week in TC. Those packs are still good today as they were new in December. The 40 amps thus far has not shown any ill effects at all. Generally when I go to the track its 4-5 charges per pack per day. There were some 3 day races in there too.

The pack I won the birds with was charged at 40 amps every single charge. I used it in both 17.5 and 13.5 TC all week in every practice and every race. Then I sent it to Josh Cyrul and he did the same with it in Modified and 13.5 sedan which he won both classes. That battery was put through hell and still cycles the same as it did when it was new a week before the birds.

The key to keeping batteries fresh is USING THEM! And making sure they dont sit with a full charge or zero charge in them. Not being used is a Lipo's worst enemy I have found.

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Old 04-02-2013, 12:17 PM   #15
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The flight guys seem to be gravitating toward 4.1V/cell charging as the best way to preserve cycle life. Obviously not an option in stock racing, but for mod or practice, why not?
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