[Elecraft] [K3] K3 Off Grid

[Steve Baum]

There are so many things to consider when you try to calculate battery
requirements for emergency operation, is it really possible to accurately
predict how long a given battery will last? Here are a few of the variables
I'm aware of -

- battery type & amp/hour rating
- starting charge state of battery
- age & condition of battery
- environmental conditions - temperature
- loads other than K3 on battery, and whether constant or intermittant
- mode(s) of transmission, i.e., PSK, CW, SSB
- transmit power used for each mode
- percentage of time for each mode vs. receive time
- total operating time desired

For me, a subjective approach makes the most sense. I would make some rough
calculations but really pay attention to suggestions of those who have real
world experience. One or two of deep cycle golf cart batteries would
probably be all I ever would need. Then remember to keep them charged!

Oh, and don't assume you need 100W to make contacts! :)

Steve
AA6VO