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lipo question for the experts

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lipo question for the experts

Old 11-02-2006, 12:10 PM
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timothy thompson
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Default lipo question for the experts

a i have a thunderpower 11.1 2100mah pack . If i switch to a 11.1 4200mah pack will i get twice the run time or is the curve exponential?? Bottom line is i want more air time
Old 11-02-2006, 12:29 PM
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Default RE: lipo question for the experts

Theoretcially and mathematically yes. However, you have to look at the dimensions and weight of the 4200 pack vs. the 2100 pack. here is the 2100 pack:

Cell Specifications
11.1 volts
Length: 3.94in. 100mm
Width: 1.34in. 34mm
Height: 0.79in 20mm
Weight: 5.01oz. 142gm


Here is the 4200 pack:

Cell Specifications
11.1 volts
Length: 3.94in. 100mm
Width: 1.34in. 34mm
Height: 1.57in 40mm
Weight: 10.02oz. 284gm


The 4200 pack is twice the weight and twice the height. (1) make sure it will fit (2) that is one heavy battery, double the weight of the 2100 and almost 3/4 of a pound [:-] The heavier battery is going to throw off your C.G. and it is going to majorly affect the performance of the plane, it is going to fly slower and heavier.

Pulling less amps is a way to get more air time. Maybe going down a little in either pitch or length of prop is a better solution than getting an anchor for a bettery
Old 11-02-2006, 02:12 PM
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Default RE: lipo question for the experts

its going in a wing b-25 need the weight! so you are saying i would more than double my endurance?
Old 11-02-2006, 02:16 PM
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Default RE: lipo question for the experts

im running two eflite 60"s with 80 amp phoenix escs the weight is welcome as its better than lead. With the 2100mah pack i get very little prop run at full power so if the mah is doubled i need to know if that only doubles my flight time (linear curve) or more than doublkes iot (expo curve) thanks
Old 11-02-2006, 02:27 PM
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Default RE: lipo question for the experts

If you need the weight then you should be good to go. Yes, doubling the mah number should in theory double your flight times. It will definitely go way up, but it should be close to double.
Old 11-02-2006, 02:30 PM
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Default RE: lipo question for the experts

You would be doubling the capacity (millamp hours) of the battery, which would then double the amount of time you can drain energy from it.
Old 11-02-2006, 02:47 PM
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Default RE: lipo question for the experts

As long as you don't increase the draw too.
Old 02-07-2007, 05:21 PM
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Default RE: lipo question for the experts

There is no simple answer. Mathematically it should double, but a 4200 pack will weigh more than the 2100 and therefore affect the motor output.

Joshua Gordon
Common Sense RC
www.CommonSenseRC.com
Toll Free 866-405-8811
Old 02-18-2007, 11:20 PM
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Default RE: lipo question for the experts

It sounds as if you already have some lead weight in your plane for adding weight reasons?

If so, adding a heavier battery with twice as high as a mah and removing some lead will basically double your flight time.

All things considered, if your total plane weight stays the same BUT your mah goes from 2100 to 4200, you'll be doubling your batteries capacity and not increasing the draw on it.

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