ORIGINAL: jkkrobbins
I fly a Multiplex Easy Star. I'm using a 7 cell 1200 mAh NiMh now. Considering a 2 cell LiPo to increase run time. But I discovered a potential issue.
My 7 cell pulls 10 amps at full throttle. A 2 cell LiPo pulls 7.5 amps and the motor clearly does not turn as fast. Although I will more than triple the run time, the high end power is a concern - i.e. how will it climb?
Is there a way to force the battery to send more current to the motor? One though - when the ESC (Pixie) is programmed, one of the steps is to slide the throttle switch to the max position. Can I trick the ESC by sliding the switch to a few clicks short of max? So when I run to true max, the ESC opens up more and allows the 7.4 volts across the motor longer, thereby increasing the motor speed to what it is now with the 8.4V pack?
Is this idea feasible, or is there another way to allow the LiPo to discharge at 10 amps and give the motor more kick?
The most likely issue is not enough voltage. Voltage is like a supercharger. On your 7 cell pack you are pumping at 8.4V and you say you are pusing 10 amps into the motor.
With the 2 cell lipo you are pumping at 7.4V, a considerable reduction in pressure, thus you are pushing fewer amps into the motor. This is not a chemistry issue or an ESC issue it is a voltage issue. If you ran a 6 cell 7.2 V nimh pack it would probably push about the same 7.5 amps as when you run the 7.4V two cell lipo.
your 1200 mah nimh are probaly 2/3 A cells. Go to full A cells and you can probably get 1800+ mah pack. Got to 8 cells for 9.6V and you will push around 13 amps giving you more power into the motor.
If you are running the stock speed 400 motor, that is about all it can take. If you go to 3 cell lipo you will push more amps and get mor power but you will burn the motor out pretty quickly.
Your next step up is a 100-150 watt brushless motor. More power from the same amps.
