Odd

I've got an inexpensive headlamp that I bought some time ago.

  It works pretty well but there is an issue.  It uses three AAA cells.

  I use it with NiMh cells from Tenergy.  Energizer Ultimate Lithiums would probably be lighter, brighter and longer life but they cost more.  

The problem is charging that third cell.  This is a Duracell charger that only charges in pairs (also, it's almost impossible to get the cells out because they are held tightly in the contacts).

  Here is a second Duracell charger which also only charges in pairs (but it is easy to get the cells out).

  Finally a third Duracell charger that which only being able to charge 2 cells at a maximum does also charge a single cell.

Ironically the chargers were purchased in reverse order - every time a new charger was tried it was worse !  Why Duracell in the first place ?  They were the only NiMh precharged cells available at the local Wal-mart at the time.  Usually I could buy the charger with cells almost as cheaply as buying the cells alone.

So I just charge the 3 cells in the last two chargers - I suppose I could find another AAA cell but it wouldn't be discharged to the same extent.

Yes, I've heard of the Maha chargers but they cost a lot.

If I wasn't so lazy I'd just rig up a charger of my own which would work on a per cell basis rather than pairs.  But I'd have to find a battery holder that doesn't hold the cells so tightly !  Also, it would be nice to use a linear supply, maybe driven by a solar charged battery ?  The linear supply wouldn't be RF noisy like the switcher based chargers.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm