Thanks Eaglerock, more types to research! Reckon I'll print out copies of the various claims from announcements of the different companies and study them in depth. The winner in the long term (10 years?) would have a combination of good value, be quick charging, long lasting with high energy output and be safe to use with minimum environmental impact. In the shorter term (5 years) the current Lithium-Ion batteries should be a safe investment re the expected increase in demand.
