Brushless Motors
03-23-2005, 03:52 PM
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Brushless Motors
What does "Cells" mean when specs are given for brushless motors? Nicad and LiPo cells have different voltage.I can understand Watts out,amps and thrust depending upon prop and weight of the plane in oz but have no explanation of cells. Hopefully someone can explain this to me.
03-23-2005, 06:18 PM
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RE: Brushless Motors
Cells refers to the number of cells either NiCd or NiMhi. So the voltage applied is No. of cells X 1.2. If they are going to specify LiPos it is usually in form of nPnS, ie:- 3S2P.
03-24-2005, 10:44 AM
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RE: Brushless Motors
Yep, and just to clarify the LiPo specs...
The nominal voltage per cell for LiPos is 3.7V. A 3S2P pack has a Series connection of 3 "cells", where each "cell" is really 2 LiPo cells connected in Parallel. So a 3S1P and a 3S2P pack will both have the same nominal voltage (11.1V), but the 3S2P pack will most likely have a higher discharge rate, and a higher capacity, due to the parallel combination of cells...
The nominal voltage per cell for LiPos is 3.7V. A 3S2P pack has a Series connection of 3 "cells", where each "cell" is really 2 LiPo cells connected in Parallel. So a 3S1P and a 3S2P pack will both have the same nominal voltage (11.1V), but the 3S2P pack will most likely have a higher discharge rate, and a higher capacity, due to the parallel combination of cells...
03-24-2005, 12:24 PM
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RE: Brushless Motors
Remember: "Sells (cells) in Series. Packs in Parallel"
For motor and ESC specifications, the term "cells" has become a measuring standard, and as avalon says above, they're referring to NiCd/NiMH cells. If a motor claims a maximum of "12 cells," that means 12 NiCd or NiMH cells.
To translate into LiPoly, here's another quick rule: "A 2S LiPoly is equal to 7-cell NiCd, and a 3S LiPoly is equal to a 10-cell NiCd."
Any LiPoly pack can be split up into a combination of 2S and 3S packs, which can in turn be used to draw a rough equivalency to a NiCd pack. For example, a 5S LiPoly pack is made up of a 2S and a 3S. 5S LiPoly cells = 2S+3S = 7+10 = 17 NiCd cells
For motor and ESC specifications, the term "cells" has become a measuring standard, and as avalon says above, they're referring to NiCd/NiMH cells. If a motor claims a maximum of "12 cells," that means 12 NiCd or NiMH cells.
To translate into LiPoly, here's another quick rule: "A 2S LiPoly is equal to 7-cell NiCd, and a 3S LiPoly is equal to a 10-cell NiCd."
Any LiPoly pack can be split up into a combination of 2S and 3S packs, which can in turn be used to draw a rough equivalency to a NiCd pack. For example, a 5S LiPoly pack is made up of a 2S and a 3S. 5S LiPoly cells = 2S+3S = 7+10 = 17 NiCd cells
