[NSRCA-discussion] LiFe batteries Hobbico

[Keith Hoard]

I had some of the LiFe batteries and A123's, both were 1100 Mah rated.  I
ran both of them thru several cycles on my West Mountain Radio CBA II.
After plotting several discharge curves on top of each other you could
definitely tell that the batteries are not the same.

  The A123 cells had a very flat discharge curve, almost like they were on a
regulator even during a continuous 4 amp load.  The LiFe's voltage curve was
fairly steep and the capacity would drop as you increased the discharge
current.

  The A123's didn't seem to care how much juice you drew, they just leveled
at ~6.6V until they were empty.   Charge at 4A, then immediately discharge
at 4A, every time the same curve.  The LiFe's curves were all over depending
on how hard the last discharge was.

   I threw out the LiFe's, and have stuck with the A123's. . .

   Ed is correct that you can't use voltage to check the remaining capacity
of the cells.  However, since you can charge them at 4 Amps all day long
(wire and connector limit, not battery), I just plug in my charger as soon
as I land and it is done before I have gotten the tank half way filled up.
Of course you can see how many Mah you're putting back in per flight and
estimate how many flights you have, but I find it easier to just top it off
each flight.

   If anyone is interested in the CBA discharge charts, I can dig them out
of my laptop and e-mail them. . . I make my 1100Mah A123 packs out of the
Black and Decker VPX brand battery packs.  It is very easy to disassemble
the pack and wire it up with heavy gauge Futaba connector using the white
wire as the balancing tap.  VPX tools have been discontinued, so you have to
go to E-bay and get them.

On Thu, Mar 4, 2010 at 9:06 PM, Ed Alt <ed_alt at hotmail.com> wrote:

>  Very flat discharge curve too, so it's more difficult to know what's left
> to go.
>
> Ed
>
>  *From:* Anthony Romano <anthonyr105 at hotmail.com>
> *Sent:* Thursday, March 04, 2010 1:56 PM
> *To:* nsrca-discussion at lists.nsrca.org
> *Subject:* Re: [NSRCA-discussion] LiFe batteries Hobbico
>
> Sounds similar to the A123 cells the GS guys have been using for a while.
> Most lipo chargers have a LiFe setting. Wonder who is making
> the cells. A123's are very tough great current capacity but heavy when
> compared to the energy density of lipos.
>
> Anthony
>
> ------------------------------
> From: johnfuqua at embarqmail.com
> To: nsrca-discussion at lists.nsrca.org
> Date: Thu, 4 Mar 2010 12:49:52 -0600
> Subject: Re: [NSRCA-discussion] LiFe batteries Hobbico
>
>  Wow Steve Kaluf.   As the nominal voltage is different assume you need a
> different charger to charge them.
>
>
>
> *From:* nsrca-discussion-bounces at lists.nsrca.org [mailto:
> nsrca-discussion-bounces at lists.nsrca.org] *On Behalf Of *brian young
> *Sent:* Thursday, March 04, 2010 12:32 PM
> *To:* General pattern discussion
> *Subject:* [NSRCA-discussion] LiFe batteries Hobbico
>
>
> Anyone try the LiFe batteries Hobbico has listed for Receivers yet?
>
> http://www.hobbico.com/radioaccys/hcam6415.html
>
> Brian
>
>
>
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-- 

Keith Hoard
Collierville, TN
khoard at gmail.com
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