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

[Greg Troxel]

"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.