voltage question

[akphill]

ok maybe someone out here can answer this me or give me a thought to ponder I have an older heli that runs on 9.6 volts would it be possible to run it on an 11.1 volt lipo or do i have to stay with the 9.6 nimh battery ? this heli is a fixed pitch and belt driven tail and is bigger than 450 size but i don't think it makes 500 size either thought that maybe could try it I have had this one for 15 yrs.

[akent]

What I would try first is a 7.4 Lipo.
The 9.6v NiMh batteries actually are at 1.2 volts when charged, so 9.6v = 8 cells.

A 7.4v Lipo will actually have 8.4v when fully charged.

If the power is too low with the 7.4, then you might try an 11.1v, but 11.1v packs will have 12.6v when fully charged. That's a lot higher than your 9.6v.

Really, without knowing what kind of electronics are in there, this is what I would do.
Best,
Kent

[Solitaire]

You could be in a "rock and a hard place" situation on that one, Phil.

7.4v could be too small for a heli that size and 11.1v might be too much, especially if it has a brushed motor. But, as Kent says, it depends on the electronics.

You could be in line for an A123 in that ole beast. A 3 cell charged is 10.8v and there are some benefits to using those, other than voltage matching. Very fast charging times, plus extended life. About the only drawback is the additional weight. Oh, and the cost.

[BTCat]

From what I can tell, the Honeybee FP went from a 9.6 Nicd to a 7.4 lipo with little, if any change to the electronics/motor. On the HBFP, the lighter weight of the lipo seems to make up some of the differance with the voltage. Also, I have know idea what kind of amperage a NiMh delivers. If I were to bet (with your money) I would think a 7.4 lipo would be worth a try if you could find something with the "C" rating and Mah necessary for a heli that big.

[lowbudget]

the FALCON 40 comes with a 8.4ni-mh battery - put a 7.4 1200 10c lipo in it - got 6inches of lift - it is time to fly or fry - now i have 11.1 1000 15c with motor fuses - no problem getting off the ground ;D = VIC

[akphill]

this copter has all futaba radio gear in it and a brush motor in it has 4 channels to fly with it would be nice to use a lipo bat instead of the nimh bats but it does'nt seem like that's a reality don't want to mess up the radio equipment I dont think the 7.4 will have enough power in it to work and the 11.1 is going to have too much power? maybe i just have to get brave and try one or the other

[19000rpm]

What heli is this Phil? Ikarus by any chance?

The only issue I see; is amount of volts the Rx, speed control and servos are going to see and how those components are rated. If the Rx/speed controller can handle the input of 11.1 then all should be good.

Judging by your description of size; the motor is going to handle 11.1 volts.

If you've lost the specs on this heli you can probably find them on-line.

Happy landings

[akphill]

yeah lost the specs to this heli think i left them in falsepass Alaska when i built it. It's an older hobby lobby model if memory serves me wrong i think its called a hobby lobby 500 electric came with a cool canopy covers all the flight mechanics from tail rotor forward to the nose never finished that part looks like a bell ranger

[Raygun]

!9000 might be right it may take it but I wonder if you could buy or build a voltage regulator you may talk to Akent and see what he has up his sleeve. I have taken the voltage regulators from automotive cigarette lighter adapters that go down to 9 to 10 volts but I don't know what kind of amps they run.. Ray