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Old Apr 13, 2009, 06:35 AM
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Charge Rate For Mini Super Cub Battery

Hi,

I have a charger suitable for the mini super cub other than the one supplied. However I need to program in what charge rate I use and I don't know the safe limit. I want to charge it as quickly as possible. The battery is a 7.4V 300mah. What MA setting do I put on my digital charger? Thanks in advance.
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Old Apr 13, 2009, 08:09 AM
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7.4v 300mah lipo recommended charge rate of 1C would be .3A

If charged & balanced with proper lipo charger & balancer then you can charge up too 2C charge rate that would equal .6A. But you do this at you're own discretion.
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Old Apr 13, 2009, 09:11 AM
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Quote:
Originally Posted by freechip
7.4v 300mah lipo recommended charge rate of 1C would be .3A

If charged & balanced with proper lipo charger & balancer then you can charge up too 2C charge rate that would equal .6A. But you do this at you're own discretion.
Manufacturers never say to charge past 1C. I've seen only a couple 2C lipos.

daydreamjay: I would charge it at .3A. It will take 45 minutes to an hour to charge. That's about the fastest most lipos will charge.
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Old Apr 13, 2009, 11:06 AM
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If it is modern chemistry you can generally charge at 2-3C (.6-.9a) with little risk of life reduction. In fact most lipos today are charged at 3-4c (Silverlit). If fast charging is really your highest priority then you can charge at even more current but expect fewer cycles.

Rule of thumb is charge at highest rate that don't heat battery.

Quote:
Originally Posted by daydreamjay
Hi,

I have a charger suitable for the mini super cub other than the one supplied. However I need to program in what charge rate I use and I don't know the safe limit. I want to charge it as quickly as possible. The battery is a 7.4V 300mah. What MA setting do I put on my digital charger? Thanks in advance.
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Old Apr 13, 2009, 12:58 PM
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^2C will heat a lot of lipos up. I've only seen a dozen or so brands that can charge at 2C. Everything else is 1C.

daydream, to find your maximum charge current, you simply take the packs MAH rating, and move the decimal value 3 places to the left, so a 300 mah battery is charged at .3 amps. 1000 mah at 1.0amps, 1500mah at 1.5 amps ect. ect. This applies to basically all batteries, although there is a short break in period for NiXX batteries, that you should charge at a lower current.
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Old Apr 13, 2009, 01:59 PM
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[QUOTE=Xpress..]^2C will heat a lot of lipos up. I've only seen a dozen or so brands that can charge at 2C. Everything else is 1C.
QUOTE]

You may be right if we are talking about NiMh. I was referring to lipo which is only ones I actually tested.
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Old Apr 13, 2009, 02:27 PM
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the mini super cub battery is cheap chemistry... not a good battery its ok for the mini cub no doubt.. however.. charge it at .3A you'll save yourself alot of heartache and that 15$ replacement fee
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Old Apr 13, 2009, 02:58 PM
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Quote:
Originally Posted by rich smith
Quote:
Originally Posted by Xpress..
^2C will heat a lot of lipos up. I've only seen a dozen or so brands that can charge at 2C. Everything else is 1C.
You may be right if we are talking about NiMh. I was referring to lipo which is only ones I actually tested.
In my case, I've charged a few lipos at 2c justto see if I could do it, and save myself time. One was a hobby city lipo, one was an impulse 2 cell lipo, and the other was 300mah lipo I found. All (not sure about the 300 mah) were less than a year old. All got pretty warm at 2C. Not ALL lipos (even modern ones) can charge at 2C. For me, I like to keep my batteries for as long as possbiel, so 1C fo me.
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Old Apr 14, 2009, 05:50 AM
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Quote:
Originally Posted by R/C_Addict
Manufacturers never say to charge past 1C. I've seen only a couple 2C lipos.
& you should never say never, because my over 1 year old FlightPower EVOLITE V2 2s & 3s LIpo have (CAN BE FAST CHARGE UP TO 2C) all on the manufacturing label on the pack them self. I have charge them at 2C with proper charger & balancer and have yet to see any side effect.

PS: I am more likely to kill my pack by abusing them (going below recommended voltage) then by charging them at 2c.

HERE's what THEY HAVE TO SAY ABOUT IT.
http://www.flightpower.ca/b2b/cart.p...category_id=49
Fast charge rates up to 2C approved in conjunction with balancing, the FlightPower V-Balance is ideally suited.
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Last edited by freechip; Apr 14, 2009 at 09:12 AM. Reason: spelling
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Old Apr 14, 2009, 11:32 AM
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As a test I have charged Loong, Zippy, and Rhino up to 4c with no overheating. Only slight reduction in lifetime. Maybe Xpress is spending too much time charging out in the sun.

I've concluded it is mostly DISCHARGE abuse that hurts lipos. They suffer 10x more increase in temperature. RCG is filled with guys wondering why their batteries puff when they are using 3s with props that are too big for even 2s.


Quote:
Originally Posted by freechip
& you should never say never, because my over 1 year old FlightPower EVOLITE V2 2s & 3s LIpo have (CAN BE FAST CHARGE UP TO 2C) all on the manufacturing label on the pack them self. I have charge them at 2C with proper charger & balancer and have yet to see any side effect.

PS: I am more likely to kill my pack by abusing them (going below recommended voltage) then by charging them at 2c.

HERE's what THEY HAVE TO SAY ABOUT IT.
http://www.flightpower.ca/b2b/cart.p...category_id=49
Fast charge rates up to 2C approved in conjunction with balancing, the FlightPower V-Balance is ideally suited.
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