This is what I got from Kevin. We also spoke on the phone.
On the phone, Kevin clarified that as long as the charger was "proper"
for LiFePO4 chemistry and charge current was safely limited, an LiFePO4
battery will NOT be damaged if charged during discharge. His only
concern was that the battery might not reach full charge simply because
more current was being drawn than was being supplied by the charger.
SO -- the bottom line is that LiFePO4 batteries ARE suitable for use as
the main power source in a station where a charger is always connected
as long as the charger has the proper charging characteristics for the
LiFePO4 in use. In general, battery life is maximized if the maximum
charging current is no greater than the 4-10 hour discharge current. For
example, a 10A charger is sold by Bioenno with their 40 - 100Ah
batteries. Higher charging currents reduce battery life.
Kevin also said that they have taken our concerns seriously with respect
to RFI from chargers, and that they have begun working on sourcing
chargers that are RF quiet. He noted that it typically takes 3-6 months
to find potential candidates, evaluate them, and get them in inventory.
I've volunteered to evaluate them in my station for noise.
Bioenno also works with Powerwerx, so they are generally aware of
connector issues. He said that they are using the larger connector as
standard because some of their customers need the larger connector with
the higher current rating. The grey SB50 connectors used in the ham
world are rated for 50A.
73, Jim K9YC
On Tue,7/12/2016 11:39 AM, Kevin Zanjani wrote:
Hi Jim,
I needed to clarify my response. Maybe it's easier to explain over
the phone. My number is 714-336-2953
The batteries with the bundled chargers, use constant current,
followed by constant voltage to charge the batteries. Generally, with
these chargers, if the battery is loaded while the charger is
attempting to charge the battery (under a high load condition), then
the battery may not be able to achieve a full charge as its loaded
under a high load condition (it would certainly charge). If the load
is fairly low amperage, that is less than the charge current, then yes
the battery can take the full charge.
With the PWR gate, you can certainly charge and discharge the battery,
because there is a separate power supply that can provide a large
enough charge current to the battery, while also supplying power to
the radio from that supply . So in that setup, it is perfectly fine.
So it depends on the charge current available to charge battery versus
the load power to ensure the battery takes a full charge.
-Kevin
On Tue, Jul 12, 2016 at 10:52 AM, Jim Brown
<[email protected] <mailto:[email protected]>> wrote:
Kevin,
I've been using the battery for about a week. Some correspondence
you had with Wes Stewart concerns me greatly -- in effect, it
negates the use of the battery in my station. I bit of background.
Most ham gear is designed to run from a DC source in the range of
12-14V, and its performance is best near the top of that range.
For many years, I've used flooded lead acid cells that are
float-charged as the primary power source for the 12V equipment in
my station, but had to accept the fact that for most of their
discharge, they are at 12V or less. The primary reason for going
to LiFePO4 chemistry is the discharge curve, with most of the
battery's capacity above 12.5V.
I am a contester. Typical contest operation for me is with two
radios, each drawing about 1.5A in receive mode and between 10-20A
in transmit mode, depending on the contest. Only one radio is
transmitting at a time. The 10A contests are 36 hour events, the
20A contests are 10 hours long. It doesn't take much arithmetic to
realize that a 100Ah battery must be charged during operation to
handle the load.
Your response to Wes seemed to indicate that LiFePO4 batteries
cannot be charged during use -- that is, that they must go through
a discharge cycle. I can find no technical references online for
this statement, so I'd like to know the basis of your advice to
Wes. Can you point me to technical references for this?
Some other comments now that I've been using the battery in my
station for several days. The PowerGate controller seems to work
fine -- IF the power supply is set to a high enough terminal
voltage to provide 10A charge current.
The 4A charger you provided for my 20Ah battery pack works fine,
but generates significant levels of RF noise. I can suppress that
noise somewhat, but not well enough, by winding multiple turns of
both AC and DC cables through ferrite cores to form common mode
chokes. I've seen comments online from other users of your
chargers indicating that they are too noisy to use in a radio
environment. As I told you last week, it is important that you
find chargers that produce far less RF noise. This is also
critical for the pro audio market, especially for video production
work.
The Power Pole connector for charging is well chosen; the larger
connector for the load is not. Ham applications have standardized
on the smaller Anderson SB50 series for use with power sources.
It's no problem for a technical user to replace the larger
connector that you ship with, but it's added cost and time. And,
of course, the technician must mount only one conductor at a time,
inserting it in the connector shell, so that there is no
possibility of shorting the battery in the process.
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