Forbes - Vanadium Flow Battery article, page-2

Great Article

This type of battery can offer almost unlimited energy capacity simply by using larger electrolyte storage tanks. It can be left completely discharged for long periods with no ill effects, making maintenance simpler than other batteries. Because of these unique properties, the new V-flow batteries reduce the cost of storage to about 5¢/kWh.
These batteries are rather large and best suited to industrial and utility scale applications. They could never fit in an electric car, so the Tesla battery is safe for now. But the V-flow battery outcompetes Li-ion, and any other solid battery, for utility-scale applications. They’re just safer, more scalable, longer-lasting and cheaper - less than half the cost per kWh.