On Mon,4/27/2015 1:33 AM, Rick - DJ0IP / NJ0IP wrote:
So the question, has anyone actually used the LiFePo for portable operations
with success?
Your question is timely, Rick. As it happens, my friend Scott, AF6RT, is
preparing for a backpacking effort to activate CM79 on 6M for those
pursuing the Fred Fish award (working all grids within the lower 48 US
states on 6M). It's a difficult hike, up 800 ft in the first 0.8 miles,
then another mile or so along the ridge to a point within the grid. Most
of the grid is water -- only a half mile by half mile is on land. He's
done this several times before.
My neighbor, W6GJB, and I are contributing to the effort by buying
LiFePO4 batteries that we're loaning to Scott, and I've loaned him my
KX3 and KXPA100 amp, which, because it's designed as a backpacking
radio, has the virtues of very low current drain on receive, light
weight, and a built-in preamp good enough that an outboard preamp is not
needed.
Glen, W6GJB, is an engineer recently retired from the space program, and
both he and I have thoroughly investigated Li battery technology as it
might apply to ham radio. We have both come to the conclusion that
LiFePO4 chemistry is the best solution for TODAY -- its terminal voltage
is in the optimum range for our ham gear, it has a very good discharge
curve (rather flat), it does not have the "easy to catch on fire or
explode" issues of Li Ion, and it is more tolerant of charging.
The battery I bought is rated 20Ah at 12V with a maximum discharge rate
of 40A. Like any battery, the Ah rating is for a far more moderate
discharge rate. :) It weighs 5 pounds, 9 ounces (on my XYL's precision
scale).
http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-20ah-lfp-battery-black-pvc-pack
It is part number BLF-1220W. It comes with Power Pole connector to go to
the load, and a concentric connector for charging. I paid $213 plus tax
and shipping, which came to about $250.
The battery that Glen bought (several months before I bought mine)
weighs 7 pounds 5 ounces, is also rated 20 Ah at 12V, and uses LiFePO4
chemistry. It comes in a somewhat larger package. He bought it here.
http://www.batteryspace.com/
Both of these companies have intelligent people responding to emails and
talking on the telephone. Their prices seem competitive and comparable
to each other. The reason for the wide diversity of part numbers and
packages is so that they can replace OEM batteries in existing products
-- everything from CPAP machines to model airplanes.
It's my understanding that this battery chemistry has been adopted by
the SOTA (summits on the air) crowd.
I just wonder if it's really worth the extra money going with this new
technology, or should I buy a cheap GEL for now and come back to LiFePo in 3
or 4 years when it is cheaper?
The reason for choosing any of the Li chemistries is WEIGHT. How many
mountains do you intend to climb in those 3-4 years?
73, Jim K9YC
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