jakdedert wrote in
:

I don't have time to check (or recharge) used batteries.

No-one's time should be that important unless they're saving a life or
something. Time these devices were fitted with lithium ion batteries.
Changing out sets of those occurs less because the energy density is good,
there;s no 'memory effect' or other reason not to top up on demand, the cost
can be low enough to compete with Procells, and changing them is as fast, or
faster, given no fiddly pop-cap connector to mess with. And you top up your
batteries at night in a charger and in the morning you have lots of new
batteries. Their energy density is good enough that you'll likely get through
a day or more of the demands a microphone makes, so if time really IS si
desperately im,piortant that you think you can't find enough to charge a
battery, think again. It will save you more than it costs.

The only serious obstacle is the possible lack of 9V PP3 shaped lithium ion
types. I don't think I've seen any yet. But a decent mic could use a DC-DC
converter and run off one or two standard CR123's just fine, and for a lot
longer too. The use of space for chemical reaction is far better in large
cells than groups of small ones.