For the occasion when all the electrons die at once, I have 2
portables.

I bought the new ICOM sport model transceiver (small size, light
weight). I keep alkaline batteries in it because they retain a charge
better than rechargeables and I need it only for emergencies. I also
have an antenna loop in my Com2 under the panel so that I can
disconnect the panel receiver and connect the Icom to the external
antenna.

For navigation I have a Garmin Pilot GPS III that can sit on the
glareshield and runs 8-10 hours on 4 AA alkalines.