[Elecraft] [KX3] LiPol battery pack and KX3 - voltage vs output

[David Christ]

I'm not an EE so maybe someone who is can answer my question.  A 
boost circuit certainly cannot have 100% efficiency, but how 
efficient would it be?  Some of the energy in the battery will be 
consumed by the boost circuit and not available to the radio.  So 
then how does one evaluate whether using a boost circuit will get you 
more operating time or not?  I presume it must have something to do 
with the flatness of the battery's discharge curve and also whether 
you need more than 5 watts.

David K0LUM

At 7:40 PM +0000 1/12/12, Thomas Horsten wrote:
>
>
>That said, does anyone on the list know of a circuit that could step up the
>voltage of the 12V LiPol cell to a regulated clean 13.8V supply? It would
>be great to be able to put out the full power continuously. I guess an
>inverter and switched mode supply could be used but that would be far
>overkill, does anyone know of any chips e.g. available from Farnell that
>could be used in such a box? The LiPol should easily be able to deliver the
>amps needed even when partially discharged, and the supply would have other
>uses too.
>
>73, Thomas