The person quoting me on an off grid solution is suggesting lead nano carbon batteries instead of Lithium Ion or ordinary lead acid.
Is this technology mature enough yet? And is this now the way to go for off-grid solutions?
Update: This the link I was given by the supplier. These are Chinese batteries that don't mention nano at all. This seems to be technology which allows the battery to operate at partial state of charge without the same risks of hard sulphation
The ALC is being tested as a replacement for the classic starter battery in start-stop applications and in 48V micro and mild hybrid systems. Rapid charging on regenerative breaking is a decisive advantage with these batteries, a task that is difficult to achieve with regular lead acid. Although larger and heavier than Li-ion, the ALC is low-cost, operates at subfreezing temperatures and does not need active cooling — advantages Li-ion cannot claim. Unlike regular lead acid, lead carbon can operate between 30 and 70 percent state-of-charge without fear of becoming sulfated. The ALC is said to outlive the regular lead acid battery, but the negative is a rapid voltage drop on discharge, resembling that of a supercapacitor.
http://batteryuniversity.com/learn/article/new_lead_acid_systems