[Elecraft] K2/100 Emergency field battery

[TIM LOGAN]

Hi folks -

I would like to hear anyone's recommendation for a battery to be used in
the field that could power the K2/100 on moderate emergency
communications traffic for 3 days if solar recharging was not available.
I realize that "moderate" is extremely subjective, but I think you get
the idea. I'm obviously not talking about a backpacking item. Any help,
particularly from those with emergency field experience would be most
appreciated. Thank you. Regards, Tim NZ7C