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
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