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Old 10-04-2007, 10:20 AM   #16
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After talking with some people in the know about lipos and the chargers to use, I would give a good look at that top of the line hyperion charger. From what I have seen it can do the lipos as well as other types of packs as well. Combined with the external LBA10 balancer, looks like a hot setup.

The Astroflight I have been hearing of issues with.
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Old 10-04-2007, 10:43 AM   #17
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the last thing we need is people promoting the "FAST"charging of lipos
thats when peoples houses or cars are lost.

orion may say it.. but ill keep charging at one c.
i also belive that if you charge at a higer rate the lipo goes south more quickly.

RESPECT THE LIPO
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Old 10-04-2007, 02:24 PM   #18
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Orion has done testing while charging at a 2c rate in which the cells have endured 2c charge rates and normal discharging in which they have typically taken in 600 charges before they notice a differance. At 20 minutes a charge for run time that comes out to around 12,000 minutes of run time for $140. Do you have an issue with running for 12,000 minutes for $140?
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Old 10-04-2007, 08:41 PM   #19
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Quote:
Originally Posted by party_wagon View Post
Orion has done testing while charging at a 2c rate in which the cells have endured 2c charge rates and normal discharging in which they have typically taken in 600 charges before they notice a differance. At 20 minutes a charge for run time that comes out to around 12,000 minutes of run time for $140. Do you have an issue with running for 12,000 minutes for $140?
I have absolutely no problems with that whatsoever myself. I run the 3200 carbons and get more then 20 minutes of runtime even on my 12 turn motors. I charge each at .75 amps because I don't mind the wait and I like the tune of 1200+ charges for 85 bones

I would like to point out a common misconception though that others have. And that is that the chargers start dropping the current output as the pack reaches capacity. This is not something the charger does. The charger simply provides a fixed voltage output (usually the cells peak voltage) and a fixed current (usually the charge rate) and both are user defined. As the pack voltage reaches equalization with the chargers voltage output the cells actually *accept* less and less current from the charger. It is simply a phenomenon of the charging method and not the job of the charger. This is why it always takes so long to squeeze out that last 10% or so.

Now if you *really* want to speed things up, don't push the envelope of the current availability, punch up the voltage a bit. Set your charger to 10% higher voltage output then the cells peak at. Then closely monitor the cells and when the voltage hits 8.4 stop the charge. You just cheated the system because the cells will still be accepting plenty of current up to 8.4 volts

Of course I don't condone it as safe or the right thing to do, but I have charged mine a few times at those rates as an experiment and it works a treat. But you MUST monitor the charge and shut down when you peak. See what you learn when you take the time to understand the theory of operation?

- Matt
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Old 10-05-2007, 09:04 AM   #20
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If the company that makes the charger or packs will warranty anything that happens at 2C, would be willing to try them.

I know that Hyperion has info about 2C charging on there newest charger being safe, and I like how they have full data going back to the charger through the balancer, etc.
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Old 10-05-2007, 09:46 AM   #21
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Originally Posted by Cain View Post
If the company that makes the charger or packs will warranty anything that happens at 2C, would be willing to try them.

I know that Hyperion has info about 2C charging on there newest charger being safe, and I like how they have full data going back to the charger through the balancer, etc.
I just don't understand why all these companies and people are buying into the hype of making more current available to the pack. Based on the theory of operation Your just generating more heat in the cells to try and cheat a system you can do in a much smarter way.

Think of the charger as a battery itself. if the charger is producing a fixed voltage matching the output of the cells (well use 8.4v for example) when the pack nears this voltage it begins to current share with it's parallel partner (the charger) and will begin refusing current exponentially. Sure your going to get it to 90% faster but at the cost of cell life. The last 10% ? Well if the pack is takeing in even 50mah at this point, your only going to force it to take 100mah now.

If you change the chargers voltage output to say 9 volts, and still charge at 1c the pack will be accepting plenty of current by the time it reaches 8.4 volts. I am willing to stake that upping the charge voltage 10% to decrease the charge time as opposed to upping the current available for the first 90% by 100% will have far less an impact on cell life of safety.

A simple firmware update to the chargers would make this so as most chargers that monitor cell voltage can produce one voltage at the output, and check the cell voltage on the fly. Using the 8.4v packs as an example, set the charge voltage to 9 volts, and have it stop the charge when the cells hit 8.4. Lock it at 1c and I'll bet it's the better way to go.

I believe the companies are going the wrong way with this, and I blame it on misinformation and lack of understanding. Remember not all these companies have true engineers developing the technology. Some people are just selling rebadged stuff from china and advertising they are capable of whatever the manufacture states or the kids in the pit claimed they can do with it. It's kinda sad to think about it really.

Not that I'm some kind of god or anything. I just did the research. I built my lipo charger from scratch and the current and voltage are adjustable. When I charged at even 8.6 volts and 1c the last 10% filled up MUCH quicker.

- Matt
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Old 10-05-2007, 09:59 AM   #22
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What do you guys think of the converter losi will be selling soon that just plugs into your current charger, then lets you charge lipos?

Here's a link to it: http://www.horizonhobby.com/Products...rodID=LOSB9607
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