[Elecraft] What battery to use?

[G3VVT at aol.com]

In a message dated 15/07/05 15:37:09 GMT Daylight Time, kk5f at earthlink.net  
writes:

I had  one rig that wouldn't function much below about 11.0 volts
due to that  effect.  Under transmit loads on the battery and with the
voltage drop  in the power cables, 11 vdc at the rig happens a lot sooner
than you'd  think for a QRO rig.


Reply: ----------------------------------------
 
The basic K2 at least seems a lot more tolerant than most radios with  an 
operating voltage range quoted in the specifications from 9 to 15VDC. An Icom  
IC-706 mkII I have will not work below 11.75VDC as the PLL section voltage  
regulator goes out of regulation below this point causing severe FM on the TX  
signal.
 
With a 12V lead acid type battery it is unwise to expect too much life left  
available when the voltage measured directly at the battery is approaching 11V 
 as the droop in voltage starts to accelerate at that point. Most  comm 
systems that I worked on with lead acid battery plant are usually set to  
disconnect the batteries at 1.75V per cell or 10.75V with a 12V system to  prevent 
permanent damage to the batteries. Even if they did not take this  action the 
available battery charge would not last too long in any case.
 
Bob, G3VVT