Altair Nanotechnologies Inc. is a company specializing in the development and manufacturing of energy storage systems for efficient power and energy management. Altair Nantechnologies designs advanced lithium-ion energy systems and batteries. Altairnanos best-known product are their lithium-ion batteries, produced by Altairs Power and Energy division. The batteries have an anode made of a lithium titanate oxide formed into a spinel structure. The titanate replaces the graphite anodes of typical lithium ion batteries. The batteries are not the only batteries to use nanomaterials, but other batteries, like those from A123 Systems generally replace the cathode rather than the anode. The primary advantage of their batteries is that they can be charged very quickly. In testing, a 35 kW·h battery pack was charged in ten minutes. Other advantages include longer life with up to 25,000 deep cycles, higher power density than other nanostructured cells, wider operating temperatures, and greater stability under electrical and mechanical stress (i.e. the cells cannot catch fire). On the other hand, a disadvantage is that they have lower specific energy than other lithium ion cells, 100 versus 120 Wh/kg. They have also been more expensive to produce, at US$2 per Wh, due to low manufacturing volumes.