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othello
HV basher
 
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Posts: 392
Join Date: Jun 2007
Location: Austria (Europe)
01.01.2009, 05:00 PM

@gyn77
Sorry for the late reply. Thank you for sharing your eagletree files. Very interesting especially since you also included a run with 12s1p A123.

Although a 12s1p A123 pack has a higher nominal voltage than your 9s zippy lipo pack, the A123 pack was only able to provide up to 3160 Watt or 100-120A due to its drop in voltage (especially at the beginning of your run where voltage dropped to 1.8V per cell as it obviously must have been relatively cold). With time (as it warmed up due to the load) the pack held its voltage better at high amp peaks - around 2.1V at 120A loads.

You were really pushing your A123 cells. If you want to get about similar performance to your 9s lipo pack you will need a 11s2p A123 pack. It has slightly less energy, wheighs around 400-500gr more but would be able to provide amp burts around 200-240A (up to 5.5KW). Average Voltage would be around 33V (comparable to your 9s lipo pack). But i don't know if the Sentillon would be able to feed as many Amps and if the motor would hold up to those high Amp peaks (efficiency can't be very good at those amp levels).

I think you were also pushing your lipos as they also dropped to 3.1V per cell when they had to provide around 170A. You might want to use a smaller pinion to reduce load on your lipos and motor.


Brushless 1:5 custom 4wd Baja based on 1:8 truggy chassie
Jazz 55-10-32, Neu 1515/2Y (1100kv), 9s2p A123 (27v), up to 3.1KW
Latest video with eagletree Data inserts: Run on asphalt

Last edited by othello; 01.01.2009 at 05:27 PM.
   
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