Barrett wrote:
Dave, the batteries are called Supreme Power 2600mA standard charge
14-16 HRS x 260mA, quick charge 4-6 HRS x 550mA. REG USA Made in China.

I am waiting for a friend to bring by his old NiCad charger and I will
give it ago. I will let you know how I got on.

For future reference would you have an idea on how long I should charge
the batteries for using the MFJ?

I don't know who or how the charger circuit has been modified. I could
ask W&S what sort of circuit has been used.



"Dave Platt" wrote in message
...
I borrowed some 1800mA and these are charging fine in the MFJ-259,
so it
looks like the
problem is with the batteries. I have never experienced this with
these type
of batteries before only NiCad's.

What brand and type are the batteries that don't work?

It's possible that you simply received a bunch of batteries that are
completely defective (open) or are counterfeit dummies. Seems a bit
implausible.

Another possibilty is that the 2600 mAh cells are actually OK, but
were delivered to you in a completely-run-down state. That seems
plausible... the manufacturer may not have precharged them, or they
may have self-discharged in storage after manufacture. The older type
of NiMH cells do have a relatively high self-discharge rate, and can
go flat after as little as three or four months of storage.

If the batteries read 0 volts, then it's possible that a smart-charger
might fail to detect their presence and start charging... I believe
that some of the newer NiMH-aware charge-control ICs depend on the
detection of _some_ voltage from the cell to detect the cell and start
the charge.

Try sticking a few of the cells into an old-style "dumb and slow" NiCd
battery charger for a few hours. These are usually fixed-current
chargers (100 mA or so) with no battery-detect or charge-cutoff
circuits, so they're not a good choice for general use with NiMH
cells. They _will_ feed some charge into the cells if the cells
aren't entirely open, and should bring the cells up to 1.0 volts or
better fairly quickly. After 2-3 hours, take the cells out of the
dumb charger, check the open-circuit voltage, and put them in your
smart-charger, and see if they are accepted and begin charging. If
so, they may be OK. If not, they're probably defective or bogus and
you may want to return them to the seller for a refund.

Since an MFJ analyzer is the sort of device that tends to sit around
unused for weeks at a time, I think that high-capacity high-self-
discharge NiMH cells (e.g. most 2500 or above) are a poor choice.
Unless you recharge for an hour or so once a week, you'll probably find
them weak or dead when you want use the analyzer.

High-capacity NiCd cells are the traditional choice for this sort of
application (and are what I use in my own MFJ). Another possibility
is the newer low-self-discharge NiMH cells, such as the Imedions,
Eneloops, Hybrios, and Hybrids. These are typically 2000-2100 mAh,
and will hold the majority of their charge for a year or more. If
your MFJ has been modified to charge NiMH properly (e.g. with a good
temperature or zero-delta-V cutoff circuit) they might be a good choice.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

I've had the same set of NIMH 2100 maH Energizer cells in my 259B for
over 3 years. I have had them on the internal charger 24x7, except when
in use. I have had no trouble with the batteries overcharging with the
internal charger in the 259B. (obviously, or I would have cooked them a
long time ago).

One thing I've learned about NIMH batteries...they don't sit well. They
do wonderfully if kept trickle charged, but if let to sit, they will
self-discharge in less than two weeks. (at least for digital camera
purposes)I've observed this on three different "sets" of NIMH AA
batteries. All act the same way. Two weeks of sitting and they will only
operate the camera a very short time. Left in the charger and put
directly into service I can shoot well over 75 pictures in a row with no
difficulty.