pete05
Heliman
Location: australia, western sydney
My Posts This: Topic Forum | I think im going to fit an ice 100 to my 6s setup and data log it.
Also i found this info while on another web site:
Here is a bit of info to help you choose, what is the best cell count to go for. I wanted to keep the same flight time and add more power. As you can see, the over all power doesn't rise heaps unless you sacrifice duration.
(Average current over the discharge)
6 cell - 5000mah = 24v x 58amps = 1400 watts - 740g - 4.1mins - 4000mah/80% dis.
8 cell - 4200mah = 31v x 49amps = 1519 watts - 784g - 4.1mins - 3360mah/80% dis.
10 cell - 3700mah= 40v x 43amps = 1720 watts - 906g - 4.2mins- 3000mah/80% dis.
12 cell - 3000mah= 48v x 35amps = 1700 watts - 870g - 4.2mins- 2400mah/80% dis.
The intersting bit is that even though you draw less current with a higher voltage setup to attain the higher power output. The pack you use is of lower capacity and there for its equivalent 'C' rating together with higher impedence for the smaller pack, gives a lower discharge rating.
i.e.
6cell 5000mah x 25c = 125amps = 58amps average = 46% of its rate continuous discharge rating
12cell 3000mah x 25c = 75amps = 35amps average = 46% " "
Something that most people don't take into account when going for a higher cell count is, that the impedence(electro-chemical resistance) increases with every cell that is added to the pack in series.
i.e.
(typical impedence of high quality cells)
5000mah cell will have an impedence of 8milli-Ohms x 6 = 48milli-Ohms total pack resistance
3000mah cell will have an impedence of 11mill-Ohms x 12 = 132milli-Ohms total pack resistance
Things to note:
1) A higher impedence cell will limit a packs current flow ability, compared to a lower impedence cell.
2) The lower the cell impedence, the less power lost in heat within the pack and the more power avaliable to do the work.
3) A higher 'C' rating means a lower impedence.
4) Lower impedence is produced by the cells having a greater plate area and in turn creating less atomic friction.
So in conclusion, the packs still get a hard life lower or higher cell count (on paper). |
