The two biggest issues with Lithium are one cost compared to lead acid they are much more expensive, and secondly the risk of fire if they are over charged Lithium can charge from say 20% - 80% very quickly, but after 80% charged this is where the case of a fire is more likely.



Lithium iron batteries could have caused a major fire earlier this year in a major warehouse in the UK. It is said that lithium iron batteries in a robot over heated and caused the fire. This was harder to put out when the fire brigade got there because they could not put out the lithium iron batteries in the equipment.

Having said this there will be a lot of development in graphene supercapacitors over the next couple of years and these could have the ability to over take both Hydrogen fuel cells and Lithium iron