WB4SON

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10 year old LiFePO4 battery still going strong

Posted: 21 Jan 2021 07:40 AM PST
https://wb4son.com/wpblog/?p=4265


I purchased my first LiFePO4 battery a decade ago from a company called K2
Energy (still in business today).Â* It was the same size as a 7 AH Lead Acid
battery, but 1/3 the weight with a 9.6 AH rating.Â* It quickly became
obvious to me that this was an outstanding battery technology for ham radio
use (voltage above 12.0 volts for more than 90% of the battery capacity,
and thousands of charge-discharge cycles of life).

After ten years of use, with hundreds of charge-discharge cycles under its
belt, it still has 8.8 AH tested capacity (92% of its original 9.6 AH
capacity).Â* This was based on a constant current C/5 discharge (1.92
Amps).Â* Under those conditions the battery remained above 12 volts output
for 96% of its capacity, and had a total run time of 4 hours and 35 minutes.

BOTTOM LINE: LiFePO4 batteries, from a credible vendor, will serve well for
more than a decade!




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An inexpensive LiFePO4 battery for POTA Activations

Posted: 20 Jan 2021 11:21 AM PST
https://wb4son.com/wpblog/?p=4263


Ive been a HUGE fan of BioEnnoPower LiFePO4 batteries and have been using
three of their devices for many years.Â* I had put together a presentation
for my radio club (Newport County Radio Club) suggesting a couple of
configurations of radios and antennas that would be useful for park
activations.Â* Part of that presentation was a suggestion to use a 16 AH
BioEnnoPower battery, which costs about $150 (without charger).Â* I still
know that is an excellent vendor and fine product.

I did run across a vendor selling a 16 AH LiFePO4 battery on Amazon for $55
(free Prime shipping).Â* Since this was 1/3 the price of the BioEnnoPower
battery, I felt compelled to buy one and test it out.

Yesterday I ran it through my battery tester to confirm the capacity
rating.Â* It tested out at 15.2 AH (95% of capacity rating), and maintained
a voltage above 12.0 volts for 90% of its capacity.Â* I note two things:

The battery was fully charged prior to the test, but I had never cycled it
before sometimes a few cycles are needed to achieve full capacity (and at
the price 15.2 AH is certainly close enough)
The charging process presented a somewhat unusual condition.Â* After
reaching full charge, the current dropped to zero, then remained off for
about 30 seconds, then turned back on at full current for 30 seconds.Â* That
pattern continued for several hours, with the amount of on time growing
shorter, and the off time growing longer.Â* My best guess is that this was
the internal battery management board equalizing the voltage on the
internal batteries.Â* Every other battery Ive owned just slowly tapers off
the charge current.


The key specifications a Charging voltage 14.6 volts, typical charge
current is 0.2C (with C determined at the 5 hour discharge rate).Â* So a 3
AH charger would be ideal.Â* But they also say you can use up to a 10 amp
charger.Â* Maximum discharge current is listed at 42 Amps