Dave wrote:Most consumer AA or AAA Lithium and some NMH rechargeable batteries have a charge controller/current limiter built into them, so while you can't abuse them they can current limit by themselves, yet still allow enough current through for charge leveling.
Maybe, but is that something you really want to test?
Sealed consumer cells (AAA, AA, C and D sized alkaline, Ni-Cad and Ni-Mh types) have a designed in weak spot, which will open and so enable the cell to vent if abused. However, given the low internal resistance of most Ni-Cad and Ni-Mh types (and here I am only talking about AAA, AA, C and D sizes), and the large discharge, or charge currents that can flow, limiting the current with a resistor is logical and sensible.
My advice whether using a primary (non-rechargeable) or secondary (rechargeable) cell or battery, mount it away from the PCB or any other electrical part, so that if the cell or battery leaks, it will not do too much damage (just ask owners of computers that have an on board back-up Ni-Cad battery that has leaked and corroded PCB tracks...
).
Second, do an annual check. If using a lithium coin cell, renew it annually.
Third, if using a secondary cell or battery (Ni-Cad or Ni-Mh), renew it every five years.
See also
this thread 
Mark