I keep a pack of alkaline batteries in the airplane.. A 30 pak I get
from Home Depot... I have switched from NiCd, NiMh, Li, etc.,
batteries to alkalines for back up in the 195 and 295 in the plane...
Also for the Lightspeeds, the prop tach meter, the LED flash lights,
etc... Also in the antenna analyzers, the frequency counter, the Nikon
F5, and on, and on, in my shop... After I idly did a cost analysis one
night I realized that by the time you purchase batteries and chargers,
and put up with the rapid self discharge, and the lower voltage, and
buying new rechargeable batteries on nearly an annual basis, you are
money ahead to simply use alkalines...

Denny