Using 3S as 2S - low power consumption?

[ched]

Probably a really stupid question but here goes. I am trying to get most flexibility from components I buy to build my first quad. So trying to use same batteries for flight and ground station.
I have some old goggles that I would like to try but they run on 7.4v, everything else would run on 11.1v. So I was wondering if I could use use the balancer plug to get 7.4v out of a 3S lipo to run goggles and use power plug to provide 11.1 to video receiver. This would obviously result in a very unbalanced lipo, would this be dangerous to do or should I just get a step down voltage regulator to run the goggles?

Thanks for any help.

[Revs]

As long as the 2s power consumption is very low it should be ok. If the cells get to far out from each other you may have issues. Just keep checking them every 10 mins.

On the balance lead, assuming the negative is pin 1, you can get 2s voltage using pin 1 and 3.

[Soler]

You could use one of these

http://www.ebay.co.uk/itm/LM2596-DC-DC-Switching-Adjustable-Step-Down-Voltage-Regulator-Buck-Converter-/271632729700?pt=LH_DefaultDomain_3&hash=item3f3e928664

2 quid.  Split the battery output,  1 lead to the receiver and 1 lead to the buck converter then to the googles. Just adjust the screw on the converter to meet the voltage requirements of the googles,

[ched]

You could use one of these
2 quid.  Split the battery output,  1 lead to the receiver and 1 lead to the buck converter then to the googles. Just adjust the screw on the converter to meet the voltage requirements of the googles,

At £2 that';s definitely the best option.
Cheers.