LiPO conversions
06-19-2006, 02:18 PM
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LiPO conversions
Someone Please help me!! I have a Electric sailplane with a 380 brushed motor. The manual says they recomend a 7 cell 8.4 volt 1000 mAh NiMH battery pack. what I would like to do is use LiPOLY but I have NO idea what size or volt! The local hobby store told me but they gave me wrong info in the past so i dont trust them at all. so If any one can help me it would be great! I do like the Tower Hobby products but there are so many to choose from .... HELP!
06-19-2006, 03:41 PM
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RE: LiPO conversions
Your choices in a lipo would be 7.4v or 11.1v. There is no inbetween. I assume you have a charger for lipo? I don't recall what a 380 motor will draw amperage wise but its very important to know this and make sure the battery is rated for it. As well as the other lipo safty rules as they can be dangerous if you don't know the facts.
06-19-2006, 05:00 PM
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RE: LiPO conversions
Yeh, you would need to use a 2 cell really, as a 3 cell pack would kill the motor in a short time.
I assume that your sailplane uses a direct drive prop, maybe a folding one of the 6X4 size approximately.
If so, then it will draw something in the region of 8 - 12 amps from the 380 motor.
You will need a lipo that can handle at least that amount of amperage, but most will now easily anyway.
Select an appropriate sized battery
(example 2 cell 1500 mah)
And note what 'C' Rating it has
Modern lipos have around either 10C 12C or 20C now.
A 10C 1500mah pack will be able to safely supply 15 amps
if it was 12C then " " " 18 amps
if it was 20C then " " " 30 amps
As 1 C is 1 times the mah capacity of the battery of which in the case of the 1500mah pack would be 1500 mah which is the same as 1.5 amps.
When going to lipos, they only weigh about 1/3 of the same mah sized nicad battery, so you may need to add balast to balance your model after converting to them.
Hope this helps you.
I assume that your sailplane uses a direct drive prop, maybe a folding one of the 6X4 size approximately.
If so, then it will draw something in the region of 8 - 12 amps from the 380 motor.
You will need a lipo that can handle at least that amount of amperage, but most will now easily anyway.
Select an appropriate sized battery
(example 2 cell 1500 mah)
And note what 'C' Rating it has
Modern lipos have around either 10C 12C or 20C now.
A 10C 1500mah pack will be able to safely supply 15 amps
if it was 12C then " " " 18 amps
if it was 20C then " " " 30 amps
As 1 C is 1 times the mah capacity of the battery of which in the case of the 1500mah pack would be 1500 mah which is the same as 1.5 amps.
When going to lipos, they only weigh about 1/3 of the same mah sized nicad battery, so you may need to add balast to balance your model after converting to them.
Hope this helps you.
06-19-2006, 11:44 PM
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RE: LiPO conversions
Something else to remember is that the voltage of a fully charged 2-cell lipo is 8.4V. So a 2-cell lipo is actually quite a good replacement for an 8.4V NiMH pack.
In addition, the much lighter weight of the lipo should give you a boost in performance and/or flight time, presuming you can still balance the plane without having to add extra weight.
- Jeff
In addition, the much lighter weight of the lipo should give you a boost in performance and/or flight time, presuming you can still balance the plane without having to add extra weight.
- Jeff
