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Old Jan 06, 2003, 08:07 PM
Registered User
Austin, TX
Joined Jul 2002
178 Posts
Can some one explain the C in charge rate? And what do you charge your He-cell at?

I need a link to explain the C in charger rate. Does it mean if I charge my 1100 He-cell at 1A that would be 1.1C? And what do you charge you He-cells at? Thanks What would 2C be? Thanks I have just been Confused. Richard SPiegel
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Old Jan 06, 2003, 09:02 PM
Mitch G's Avatar
Naperville, IL USA
Joined Nov 2000
1,886 Posts
C is the cell's capacity. So for an 1100mAh cell, C=1100mA or 1.1A.
If you charge a 1100mAh cell at 1A, then you are charging at 0.9C.

I generally charge my HECELL 1100 cells at 1100mA. But, I top them off at the field at 1800 or 2200mA to warm them up a bit.

You may also want to look at the FAQ for a full discourse on battery technology and terminology.


Mitch
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Old Jan 07, 2003, 10:19 AM
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United States, NY, Spencerport
Joined Oct 2001
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C is actually the one-hour charge rate for a given cell. That "mAh" value on the cells is milliamp hours, 1/1000's of an Amp times one hour. An 1100mAh battery can (theoretically) maintain a current of 1100mA for one hour, or any combination of hours and milliamps that can be multiplied together to get 1100mAh.

For an 1100mAh battery, C is 1100mA or 1.1A because 1100mA times 1 hour is 1100mAh. In reality, the charging process is not 100% efficient, so it will take a bit more than an hour to charge a battery at C if it is completely depleted. Most of the time, though, the battery is somewhat less than 100% depleted, so charging will actually end up taking less than an hour.
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Old Jan 07, 2003, 01:17 PM
Mitch G's Avatar
Naperville, IL USA
Joined Nov 2000
1,886 Posts
Quote:
Originally posted by mkirsch1
C is actually the one-hour charge rate for a given cell.
True. Thanks for the correction.


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Old Jan 07, 2003, 03:24 PM
Registered User
washington state
Joined Dec 2002
185 Posts
All the replys were very good, but i'm guessing
what He really wanted to know is.


1/C charge = 1700 Mha charge rate
C/1 charge = 1/10 of 1700 Mha = 170 Mha
C/2 charge = 2/10 or 1/5 of 1700 Mha =340 Mha
ect.
ect.

Depends on where ya put the C

I think


Oldman
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Old Jan 07, 2003, 07:11 PM
Registered User
Austin, TX
Joined Jul 2002
178 Posts
Thanks

I get it now thanks
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Old Jan 07, 2003, 08:39 PM
Senior Moment Member
Virginia Beach, Va.
Joined Jan 2002
1,233 Posts
Here's my version

1C = 1700 mah 2C would be 3400

C/10 = 1/10 of C or 170ma

C/20 = 1/20 of C or 85ma


Jimmy
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Old Jan 07, 2003, 11:37 PM
Registered User
Austin, TX
Joined Jul 2002
178 Posts
600AE charge rate?

What is the charge rate for 600AE I have searched some and can not find some facts. I would asume that NiCad would be able to take 2C then. And most NIMH can take 1C. I have a pack of HRSCU 3000 That were charged at 1.5A for the first 5-10 time on a cg-340 and now that I have a Astro Flight 110 Deluxe I can see why my flight times are short it only charges to 2000-2400 and this last charge tonight it only took 1500. We'll that is what I get for buying Cheep. I will buy the GP3300 matched and zapped next time. I have flown with this pack and love it it charges to 3000-3300 and has good power. Thanks for all your help. Richard Spiegel
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Old Jan 08, 2003, 02:53 AM
EDF Head
Haldor's Avatar
Stavanger, Norway
Joined Feb 2000
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Re: 600AE charge rate?

Quote:
Originally posted by rspiegel
What is the charge rate for 600AE I have searched some and can not find some facts. I would asume that NiCad would be able to take 2C then.
Yes - the 600AE's should take 2C pretty well, 3C in a jam. If the cell is only warm once peaked there is no worry. Hot is not so good though..
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Old Jan 08, 2003, 05:56 AM
(aka Cliff Lawson)
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United Kingdom, Essex
Joined Oct 2001
1,897 Posts
Hi,

I've often seen my Supernova 250S in "auto" mode put at least 1.8A (3C) into 600AEs on charge and they have had hundreds of cycles and are still going strong. So I don't think there's any problem with even 3C (cells are only ever warm, but not hot off the charger)

Cliff
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Old Jan 08, 2003, 10:50 AM
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United States, NY, Spencerport
Joined Oct 2001
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If you are unsure of what rate to charge a battery at, use 1C. It's a good safe charge rate that works well for both NiMH and NiCd.

Most NiCd cells can be charged at 2C or even 3C. It depends on the quality of the cells. Good Sanyo cells can handle 2C. Transmitter and receiver packs should be limited to 1C, because they use cheaper cells with high internal resistance. They'll just get hot. Larger SubC cells can take 3C charge rates. You really have to look for anecdotal evidence regarding charge rates, or experiment yourself. Just keep an eye on the NiCds you're charging and make sure they don't start getting hot. If they get hot, you're charging them too quickly.

Current NiMH technology is safe at 1C. Larger Sub C type cells, like the 3000's, are okay at 2C, but you should keep an eye on the cells the first few times to make sure they're not getting hot. NiMH cells can also benefit from a slow "forming charge" at C/10 the first time they're charged. Slow charge, discharge, then quick charge at 1C.
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