I've heard it mentioned from a battery manufacturer that the EU will ban production of Lead-Acid batteries from 2012 - will we go to Ni-Cad, with similar overheat problems, or to the new high-capacity Li
Highly unlikely lead acid will be banned, since lead acid is the only battery technology that can be charged satisfactorily from a simple constant voltage source (an alternator with a voltage regulator). One would need a major change in car and plane electrics to use a NICD/NIMH or LI battery.
I've designed countless charging circuits for battery powered appliances over the years.
NICD or NIMH needs a constant current charger with a voltage and/or temperature-rise based cutoff. I wonder how they charge the ones used in jets?