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Old 04-02-2013, 11:18 AM   #16
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EAM - After a race in say 17.5 TC. Do you further discharge the pack before charging or just charge it back up?
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Old 04-02-2013, 11:35 AM   #17
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EAM - After a race in say 17.5 TC. Do you further discharge the pack before charging or just charge it back up?
Shaun,

We race 6 minute heats at our track and I usually leave the pack at that voltage after a race. It seems to work really well for me. If I break or dont finish a run I'll discharge the pack a bit.

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Old 04-02-2013, 12:29 PM   #18
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Quote:
Originally Posted by Mi4cxl View Post
10amps everywhere I run.
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Originally Posted by EAMotorsports View Post

...We race 6 minute heats at our track and I usually leave the pack at that voltage after a race. It seems to work really well for me. If I break or dont finish a run I'll discharge the pack a bit.
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Old 04-02-2013, 12:47 PM   #19
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Most of my batteries will do 5 c but i dont charge them more than 10amps. Batteries
Might be rated higher but its still considered generally unsafe.
Tx/rx packs i charge at 1c always.

Never seen 1c rules enforced. People are usually too busy running the race to care about that.
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Old 04-02-2013, 01:14 PM   #20
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Charge my IP 80c at around 40 amps. No ill effects till now. It does go to 4.1 (it is a flight charger so think the consensus is right to not charge uptil 4.2 plus volts).
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Old 04-02-2013, 01:28 PM   #21
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Originally Posted by Mr RCTech View Post
There's new lipo battery technology.

Who else is charging higher then 1C?
It all depend on the battery and charger specification. Majority of the LiPO are 1C (1 times its capacity) for charging current rate.
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Old 04-02-2013, 01:48 PM   #22
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it isn't 1C is 5amp charge?..EA charged at 40amp which is 8C??
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Old 04-02-2013, 01:55 PM   #23
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Originally Posted by OVA View Post
it isn't 1C is 5amp charge?..EA charged at 40amp which is 8C??
Only if the battery is 5000mAh. With a 7000mAh battery 1C=7A and 5C would be 35A

40A is still over 5C unless it's an 8000mAh or higher capacity.


Fortunately most new lipo cells can take some serious abuse
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Old 04-02-2013, 07:08 PM   #24
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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.
What amp rate have you been charging the same pack previously?
6 amps - Now 20 amps - went from 47.3 IR to 6.1 IR on the first charge!

How old and what brand lipo was it?
Venom 2cell lipo 60C - 2 1/2 years old.

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

Measuring IR with a new Track Power VR-1.
Its measures IR throughtout the discharge cycle.

I think the higher charge rate puts light heat naturally into the cell waking them up on the first charge and lowering the IR right away.
The lipos are not hot just slightly above room temperature.

One C charge really does nothing for IR and would not be good for competition.....
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Old 04-02-2013, 07:57 PM   #25
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At club level, with no temp Check, then a lower IR with hotter cells is preferable, but the risk of fire is higher.... I store at 7.70 volt per pack as per instruction, and I try to always End up with a higher voltage than 7.6volts after my runs....
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Old 04-02-2013, 08:27 PM   #26
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Usual club charges are 14 amps , I only bring my 208 icharger to the races. I had an old turnigy 4,000 2s pack that was destin for the trash. I tried to charge it at 70amps (outside on the concrete) with the 4010, but it just melted solder joints inside the pack.
Questions on long term storage, my 1 cells won't see use for awhile.
. Is freezing them a good option at storage voltage (makes sense in my head)
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Old 04-02-2013, 08:42 PM   #27
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Originally Posted by EAMotorsports View Post
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.

EA
what battery are you using?
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Old 04-02-2013, 08:49 PM   #28
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Originally Posted by EAMotorsports View Post
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.

EA
What brand Lipos are you charging at 40amps? We have PowerLabs and can also charge at 40amps.
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Old 04-02-2013, 08:51 PM   #29
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What brand Lipos are you charging at 40amps? We have PowerLabs and can also charge at 40amps.
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what battery are you using?
My own brand. Www.teameam.com

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Old 04-02-2013, 08:55 PM   #30
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My own brand. Www.teameam.com

EA
i can say with all words thats a great battery!!

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