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Hobby Lobby all-in-one combo question

Old 04-22-2007, 02:01 AM
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Default Hobby Lobby all-in-one combo question

I recently purchased an Alfa Models P-47 "all-in-one" combo package, and had a few question regarding getting longer flight times. The combo I chose for a specific reason. It included a Graupner speed 300 6v motor, running a 5:1 gear reduction, Jeti jes 012 12a ESC, 720 mAh 8 AAA cell NiMH pack, Apache 2030 charger capable of charging 4-8c NiMH or 2-3c Lipo at a max of 1200 mAh. I chose to get this combo as opposed to the brushless setups, as I wanted a slower flying, easier and cheaper to maintian power-train, and the charger gives me the flexability to upgrade to lipo for more power and longer flights- leading to my question. I am a realative newbie when it comes to electrics, so forgive me, but I need assistance in choosing a lipo setup that is compatable with my charger and won't fry my ESC or motor. The battery I was looking at was a 2c 2100 mAh Thunder Power Lipo, which will lighten the power-train just slightly, overall. Is the battery's 2100 mAh too much for my ESC or motor, and can my charger do the job @ 1200 mAh (if so, how long to charge fully?) Will the drop in voltage to 7.4 (lipo) make an adverse difference in performance? Will I also need a balancer in addition to my charger, or can the 2030 be adapted to charge on the balancing lead? Will I need to change my prop? (currently running APC 9x6) If the 2100 is too much, or little, for that matter, what do you suggest? I have run the numbers for my current setup and the 2100 lipo setup through Motocalc, and the results are very similar, any differences between the two end up reading in a few areas lower on the lipo setup as opposed to the 720 mAh NiMH. Flight times of 17-19 mins w/ lipo vs 6-7 mins NiMH, if the input is correct. Needless to say, 20 min flight times sound much better than 6 min ones! I have tried to read the forums as much as possible about anything relating to my questions, but this all sounds like a foreign language to me still. I am learning, but any help or insight in this process is greatly appreciated.
Old 04-22-2007, 10:47 PM
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Default RE: Hobby Lobby all-in-one combo question

The 2 cell li-poly battery will increase performance only in the area of extended flight times. It's always a good idea to go with a balancer and I would suggest the Blinky balancer made by Astroflight. The Li-poly will have slightly lower voltage under load than the Nimhd at least in theory. I would test it with the same prop before deciding if you need an upgrade in the prop. You may find that the new battery will actually have a similar if not superior voltage under load compared to the Nimhd. If you charger can only go to 1200 mah it will take approx 2 hours to charge the Li-Poly battery. If you say that you have a 730 mah NiMhd battery and you are going to a 2100 mah Li-Poly battery that would mean you have three times the capacity and therefor you will have approx 3 times the flight duration. Since the battery is a bit lighter it will be very slightly better but you can only use 75% of the Li-Poly battery safely so the actual usalble flight times will be 75% of what you see in Motocalc.

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