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Pete's Planes |
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| Konion lithium ion cells |
| In Q&EFI magazine, May 04, Bob Smith reports his discharge test on a 3S 2P
pack. Bob's data is listed here, but altered to "per cell". constant current 10 A discharge time 6.9 minutes discharge capacity 69 AM [=1155mAh] average EMF 3.2V [extracted from graph] weight 41g
I have used the above data to produce some interesting numbers. discharge energy = 69AM * 3.2V = 221WM [per cell] average power = 221WM / 6.9M = 32W [per cell] average power/weight = 32W / 41g = .78W/g = 353W/lb energy/weight = 221WM /41g = 5.4WM/g
The supplier claims a max continuous discharge current of 13A. This would increase the power/weight to about 400W/lb. To obtain a "battery power/model weight" of 100W/lb the battery weight would be 25% of the model all-up weight.
The parameters "power/weight" and "energy/weight" apply to any number of cells, and to any pack configuration, and for any cell voltage. These are the most meaningful parameters to use when comparing cells. "energy/weight" is an understandable name for what is usually referred to, enigmatically, as "energy density".
Abbreviations: M minutes AM amp minutes WM watt minutes WM/g watt minutes per gram WM/lb watt minutes per pound W/g watts per gram W/lb watts per pound
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