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The Terminator II - super charge your A123 packs!

Old 08-18-2008, 01:22 AM
  #26  
simibill
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I don't think any of my ESC's are programmable. It's gonna cost me a bunch to convert to A123 cells.
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Old 08-18-2008, 02:31 AM
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Bummer!
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Old 08-18-2008, 04:06 AM
  #28  
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Many ESC have an Auto Ni setting which works very well with A123s. I have several of the Suppo brand one which I purchased from lightflight.com and their auto Ni setting works great.

With A123s you really do not need a LVC and you must use a timer. Power is 100% until the very end and then nothing.


Charles
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Old 08-18-2008, 09:37 PM
  #29  
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Originally Posted by everydayflyer View Post
With A123s you really do not need a LVC and you must use a timer. Power is 100% until the very end and then nothing.

Charles
Yes, but how do you set a timer when you do not know the appropriate point the pack is about to reach the very end?
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Old 08-18-2008, 09:40 PM
  #30  
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Originally Posted by Larry3215 View Post
Bummer!
Larry,

With your two 3S packs in series what is the peak voltage when fully charged? I have a couple of ESC's that I can program to cutoff at 70% of the starting pack voltage. Do you think this would work for A123 packs?

-BILL-
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Old 08-18-2008, 09:47 PM
  #31  
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Originally Posted by simibill View Post
Yes, but how do you set a timer when you do not know the appropriate point the pack is about to reach the very end?
Fly for a while, then stop and re-charge the pack.

Make a note of the capacity that you put back into the pack and adjust your flight times up or down accordingly.

Thats the way I do it.

I have different times set on my tx alarm for each plane. I dont fly to the bitter end either. My target is around 80%.

I like a little reserve for go arounds or if I get over enthusiastic with the throttle showing off
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Old 08-18-2008, 09:54 PM
  #32  
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Originally Posted by simibill View Post
Larry,

With your two 3S packs in series what is the peak voltage when fully charged? I have a couple of ESC's that I can program to cutoff at 70% of the starting pack voltage. Do you think this would work for A123 packs?

-BILL-
When it first comes off the terminator its around 22.8 volts, but it very quickly drops down into the 21.5 volt range.

70% of that would be 15 volts or around 2.5 volts per cell. Still on the hi side for a cut off voltage. If your pulling very many amps at all you will hit 2.5 volts fairly early. If the draw is moderate, that might work - say 10C or so maybe.

If you could turn off the lvc completely or change it to NIMH that would be best.

Charles posted a graph of these cells voltage under load that shows the voltage drop very well at different rates. It was lower than I thought it would be from previous reports I had read.
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Old 08-18-2008, 10:00 PM
  #33  
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I remembered wrong - you could go to closer to 18C with a 2.5 volt cutoff - up to 40 amps would be safe.

http://www.wattflyer.com/forums/showthread.php?t=36687

Check out the first graph. He does 10, 20, 30, 40 and 50 amp runs and all of them except the 50 amp run stay above 2.5 volts for most of the discharge.
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Old 02-20-2009, 10:34 AM
  #34  
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Originally Posted by Larry3215 View Post
I remembered wrong - you could go to closer to 18C with a 2.5 volt cutoff - up to 40 amps would be safe.

http://www.wattflyer.com/forums/showthread.php?t=36687

Check out the first graph. He does 10, 20, 30, 40 and 50 amp runs and all of them except the 50 amp run stay above 2.5 volts for most of the discharge.
Hmmm, How did i miss this thread, Lots of great info here, Thanks Larry, adding to my A123 education Take care, Chellie
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