Glider Battery?
06-16-2011, 04:33 AM
#3
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RE: Glider Battery?
In short: get the battery type that your ESC supports. Most ESC:s have the BEC function to supply the receiver and servos with power. Most of them also have the auto-cut-off function, that cuts the motor power when the battery level goes down to ensure that there allways is enough power left in the battery to supply the receiver and servos. If you usa a battery type that the ESC don't recognize it may deplete the battery completly with disastrous result.
On the other hand, I totally agree with handyman that your plane probably will be a better plane if you change that brushed motor to a brushless one, since you then have the opportunity to get a lighter plane with higher thrust. That is since the brushless motors have more power per gram of motor than the brushed motors have. Just one word of caution. Since a new motor probably will be about half the weight of the old one you may end up with the nose being too light to get the CG correct. If you have room in the nose you could allways use a heavier battery (with more capacity) to get it to balance. Then you haven't got any weight gain, but you will have a thrust gain and will get longer flights due to the higher capacity battery.
Another option is to change for a brushless motor, a medium sized battery, and lengthen the nose to get the correct CG. That might get to considerable benefits, but it's worth a thread of it's own. Anyway, I think (but I am in no way an expert, I'm still in the begiinning of the learning curve myself) that you wiant approximately 100W per lbs (200W/kg).
Again: I'm definitely no expert, so I hope others will correct any errors I have made.
/Stefan
On the other hand, I totally agree with handyman that your plane probably will be a better plane if you change that brushed motor to a brushless one, since you then have the opportunity to get a lighter plane with higher thrust. That is since the brushless motors have more power per gram of motor than the brushed motors have. Just one word of caution. Since a new motor probably will be about half the weight of the old one you may end up with the nose being too light to get the CG correct. If you have room in the nose you could allways use a heavier battery (with more capacity) to get it to balance. Then you haven't got any weight gain, but you will have a thrust gain and will get longer flights due to the higher capacity battery.
Another option is to change for a brushless motor, a medium sized battery, and lengthen the nose to get the correct CG. That might get to considerable benefits, but it's worth a thread of it's own. Anyway, I think (but I am in no way an expert, I'm still in the begiinning of the learning curve myself) that you wiant approximately 100W per lbs (200W/kg).
Again: I'm definitely no expert, so I hope others will correct any errors I have made.
/Stefan
06-16-2011, 09:53 AM
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RE: Glider Battery?
Most of the older brushed systems on 2 meter gliders were intended to be used with 7 cell Nicad or NiMh packs. The Lipo equivalent would be a 2S or 2 in Series pack which gives you 7.4 volts. Check the dimensions on your model and in the specs for the battery packs but it is likely that the opening in the glider for the battery is large enough to hold a 2S 2500mah pack easily. And perhaps even a 3000 mah will fit. Different cells are different size forms so if one brand has a width or length that is too big check some other brands and you'll likely find a pack of the same or more capacity that is differently shaped and fits your model.
Note that if you go for a Lipo pack that you MUST use a lipo rated charger. If your model came with a charger intended to use with Nicads or NiMH cells only then it's not useable with Lipo packs.
Note that if you go for a Lipo pack that you MUST use a lipo rated charger. If your model came with a charger intended to use with Nicads or NiMH cells only then it's not useable with Lipo packs.
06-16-2011, 07:57 PM
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RE: Glider Battery?
The Lipo battery is just a voltage and current source. It'll run a brushless or brushed motor setup just fine. If you want to upgrade to brushless then go for it. You'll likely save some wieght since brushless motors are a lot lighter for the same power. Or you can put in a more powerful motor to avoid adding nose weight along with the new motor and achieve a really rocket like climb. It's your choice.
