CY> Hooking the battery to a conventional charger showed no current
 CY> flow.
> I'm getting current flow with a little "power supply" hooked up to
'em.
Your batteries are in fairly good shape then. CY> charger.  I use the same 
home
brew charger for 2V and 12V
 CY> batteries.  I set the current to C/20 or C/40 and let it charge
 CY> for a couple of days.
> Do you have a circuit for this?
I think the schematic came with one of those 3 pin regulator chips.
Some of them can be used as a voltage or current regulator.  They are
rated at 1 A.  I am running it at .5 A  max due to insufficient heat
sink.  That is enough for charging the 4 Ah batteries I have.  For
higher current, and added pass transistor is needed.  I think the ap
notes included schematics for such a circuit also.
> ... the idea of hooking these in parallel
> with each other.  I'd rather come up with an arrangment that
> provides for some isolation,  if possible,
If you are interested in doing this cheaply, why not use some kind of
connectors on each battery?  Then you could easily test each battery by
disconnecting all but one to see if if it will run a load.
> I think that the limit in this case is being set by the little
> "power supply" (transformer-bridge-filter) that I'm using,
> it seems to be capable of maybe a bit more than an amp
> or so of output.
Sounds like you have the perfect setup as long as you don't care
about the long time it takes to charge.
 CY> If the voltage goes below the rated battery voltage while
 CY> charging, you probably have a shorted cell and should discard
 CY> the battery.
> At what point is it safe to assume this?  I'd like to
> automate detecting this condition if it's at all possible...
Don't know an exact answer.  I suggest that you charge several of your
discharged batteries and figure out how long that normally takes.  I
would discard any battery that is not charged after much more than the
normal charge time.
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