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If you arrived here from an external page,
please read how these tests were done.
Weight, mAh Rating & Length of Service
in QRP Applications
These two graphs illustrate the cost &
weight required to achieve a given discharge curve. In the case
of rechargeable batteries, cost is derived from the initial
cost of the batteries and charger divided by the expected number
of charge/discharge cycles typical of the battery type. For
non-rechargeable batteries, cost was averaged from several online
& local sources.
Smaller Batteries
Larger Batteries
Conclusions
These tests are comparative - a QRP rig will
discharge the batteries differently than my steady 300 mA rate
used for the batteries tested here. However, some of the differences
between battery types are so large as to render this irrelevent
when comparing one type to another. For years, I used nothing
but AA alkaline batteries in the field (and at home to manually
plot discharge curves). Then I switched to LiPo batteries and
made the same manual plots, using either my ATS3, KX1 or Norcal
40A. Comparisons between these battery types closely represent
the curves shown here, which were done automatically (allowing
me to sleep through them in some cases!).
Each QRPer has his own expectations from a
battery during QRP TTF, FoBB, Field Day or whatever else drives
some of us to operate amongst the critters afield - how much
operating time is required, the weight you're willing to carry
& the price you're willing to pay.
Remember when looking at these graphs to not
only pay attention to the Amp-Hours (X-axis) of a given battery
but the rate at which voltages decreases. Alkalines steadily
decrease in voltage throughout their discharge while LiPos stay
virtually steady till the bitter end. This available voltage
over the life of a battery's charge directly translates into
RF available out of your QRP rig.
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