In article ,
P.R.Brady wrote:
The odd thing about these devices is that voltage is not what should be
important
- wattage should be, just as with mains driven ones.

They all use standard sized cells - 'sub C' size - so the only way to
increase battery capacity is by increasing the voltage, given that
parallel connection of Ni-Cads etc is a practical no-no.

--
*Forget about World Peace...Visualize using your turn signal.

Dave Plowman London SW 12
RIP Acorn