[Elecraft] KX3 What Batteries/Quality Power Supply to Choose?

[Chip Stratton]

I have 8 of the Sanyo XX 2400 mAh cells in my KX3. Testing capacity with
the MAHA C-9000 gave me more than 2300 mAh for each of the 8 at a 500 mA
discharge rate. They seemed to cluster round 2350 mAh. This was after
performing the "break-in" cycle on the C-9000 and a 200 mA top-off charge
for a few hours and after a 20 minute rest.

Chip
AE5KA


On Fri, Jan 4, 2013 at 1:26 PM, Greg Troxel <gdt at work.lexort.com> wrote:

> "Fred Smith" <mfsj at mo-net.com> writes:
>
> > As in larger size, exact type, brand, number on times they can be
> recharged
> > even best place to buy them. Is an external charger/conditioner needed or
> > helpful to have? Have never bought rechargeable batteries before so
> thought
> > I would turn to the group for input.
>
> My advice, perhaps a little more definitive than it should be:
>
>   Do not get agitated about cost.  We are talking 8 * AA, and the good
>   ones are only $20-30.  I have had bad experiences with cheap NiMH
>   (Nexcell, early failure).  It's not worth risking trouble from by
>   buying junk (see the archives for 'smoke came out of my kx3', which
>   seems at least possibly due to bad batteries).
>
>   Buy only name-brand batteries from one of the well-known brands, which
>   is at least: Maha/Powerex, Sony/Sanyo (and perhaps more).  (I remember
>   eneloop being made by Sony, but it seems to be Sanyo now.)
>
>   Buy only Ultra-low discharge, because NiMH batteries used to have a
>   moderately high self-discharge rate, and then over the last 7? years
>   the race for higher claimed capacities led to really high
>   self-discharge rates, to the point where a battery was totally useless
>   two weeks after charging.  The actual capacity you will experience
>   from non-ULD batteries will very likely be much less because of this,
>   unless you really do charge one day and use the next (always).
>
>   Do not be overly concerned about capacity, as the difference between
>   high and low isn't that great.  Also the actual capacity you'll see
>   will not quite be the nominal.
>
>   If you're in the mood, get a tester, so you can measure capacity.
>   Otherwise you don't really know if the cells are still ok.  I
>   recommend the Maha C9000.  It takes too many button presses to
>   operate, but otherwise I like it.
>
>   Expect to replace them after a few years.  When one in the group of 8
>   doesn't work so well (test them yearly, or if you notice trouble), buy
>   a new set for the KX3 and use the remaining good ones for random other
>   things.
>
> I have some unlabeled green Sanyo-made batteries that I bought surplus
> in 2001 from Hosfelt.  These are mostly (13/16?) still ok, and hold a
> charge for a few months.  You can't buy these any more, and wouldn't
> want to, but it's an interesting comment on batteries before the
> capacity craze, and a postive Sanyo experience.
>
> Specific recommendations are:
>
>   Sanyo Eneloop, nominal capacity 2000 (I tested these, and they were at
>   1850 mAh (200mA rate) new, and after sitting 129 days, provided 1703
>   mAh).  That's 92%, and assuming constant-fraction loss, 79% after a
>   year, which meets their 75% spec.
>
>   Maha Imedion, nominal capacity 2100.  I have had 8 of these for
>   several years, using them in pairs in GPS receivers.  One has failed,
>   and the others are fine.  I have not done the 129-day experiment, but
>   they really seem to hold a charge over time fine.  But it seems that
>   now the nominal capacity is 2400.
>
>   I would be tempted to try the Eneloop XX, but they seem quite a bit
>   more expensive than the regular ones, for only 25% more capacity.  (If
>   someone has them, it would be nice to post C9000 results.)
>
>   Thomas Distributing is a good place for maha (also sells via amazon).
>   I've bought things from them over the years with good experiences.
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