RCU Forums - View Single Post - New 1100 mAh A123 available everywhere and no word here!
Old 10-27-2008, 10:09 AM
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everydayflyer
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Default RE: New 1100 mAh A123 available everywhere and no word here!

Correct on SOP , LVC Low Voltage Cutoff (point where ESC either stops motor or pulses it).

I have been posting CBA graphs of A123s under different loads for over two years now. Just like LiPolys it depends on discharge rate and load.

Fact is the very first post in this thread has a CBA graph showing these 1100 being discharged at 6-21 amps.

http://www.rcuniverse.com/forum/fb.asp?m=6590509

I flew LiPolys for years and then made the switch to A123s. I love the fast charges,hundereds upon hundreds of cycles life, no fear of venting with flames, etc.

Cost . To me it has always been cost per flight. I have been very careful with top of the line expensive LiPolys and gotten perhaps 200 flights before performance really started to drop. I have abused A123 and have 300 to 500 flights on packs that are still going strong.

A 5S A123 2300 which cost approx. $90 to $100 if you purchase it pre built flys my 48" WS / 3 to 4 1/2 aircraft as well as a 4S 3300-3700 LiPoly which cost $140 to $180 and once again the A123 will last 2,3 perhaps 4 times longer and can be charged much faster. '

LiPolys drop voltage on a curve during a flight so by mid flight you have less power than at the first of flight, A123s stay very close to the same power until they are empty.

LVC references of 2.0 for A123s and 3.0-3.2 for LiPoly.

LVC of 2.0 per cell for A123 will result in close to an unloaded / resting voltage of 3.2 per cell and 95% of capacity used if power system is correctly matched.

LVC of 3.2 violts per cell with LiPoly will result in open / no load voltage of approx. 3.7-3.8 volts per cell and 80 to 90% of capacity used.

Using 100% capacity of A123s does not hurt them. using more than 80% of LiPolys capacity does harm them.


Charging: I charge A123 2300 at up to 10C. I have charged the 100s at 10C but really feel that 5C is better for the 1100s as they retain heat more due to thier steel construction.

If you really want to learn about A123s then RC Groups is a much better site.

Here is my A123s links post .

http://www.rcgroups.com/forums/showp...01&postcount=2

Charles