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Old 12-26-2008, 09:23 AM   #1
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Default lipo:3s or 2s???

hi guys,little question:

if i want more runtime,is better a 3s lipo or a 2s lipo???

or everything depends on how much ampere has the battery???? type +ampere=+runtime????


p.s. sorry for my english
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Old 12-26-2008, 10:07 AM   #2
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A three cell lipo is going to have a higher voltage then a two cell lipo I wouldn't say that your going to get more run time though out of a three cell vs a two cell that all depends on the mah. becareful though you may end up burning up your speed control or motor if its not rated to handle 3 cell lipos.
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Old 12-26-2008, 10:14 AM   #3
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Runtime equates to mAh numbers.

Runtime of 2S 4000mAh is lower than 2S 5400mAh.

The "h" is "hour" - think time. MilliAmp Hour. Amps over time is runtime.

Now, 3S is higher voltage - if you went from 2S 3800 to 3S 5400 - you get more runtime and some insane speed vs. the 2S. You may get less runtime - because you'll run faster and may break A-arms, easier Also, some ESCs will not allow higher voltage of 3S vs. 2S. More likely, you should stick with 2S and go as high as you can afford with the mAh numbers.
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Old 12-27-2008, 05:16 AM   #4
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ok,thanks to all for the answers
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Old 12-27-2008, 07:24 AM   #5
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In very general terms, total battery power capacity is its capacity (mAh) times voltage (# of cells).

In that sense, a 2S 4500mAh is equivalent to a 3S 3000mAh.

However, that's only true if you change the motor kV to compensate for higher voltage to keep the same RPM.

For example, to get the same speed and runtime you'd want either a 2S 4500mAh Lipo with a 5700kV motor, or a 3S 3000mAh Lipo with a 3800kV motor.

If you keep the same motor, and plug in a higher voltage battery, you will get more speed and shorter runtime.

(Also, if supported by your ESC/motor, a higher voltage setup *may* be a *little* more efficient overall, but this usually matters more at high-cell counts like 4S vs. 6S.)

Edit: In your case, if you're already using a 2S Lipo, and you want longer runtime, it will be a lot easier to change to another 2S Lipo with a higher capacity (mAh rating), since that way you will not need to change the motor or ESC.
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