Patent ID: 7721601

Claim:
A method for determining the hydrogen fill level in a hydrogen storage tank containing a solid-state hydrogen storage media, the method comprising: equipping the hydrogen storage tank with at least one compartment for storing the storage media, passages for transporting hydrogen gas to the hydrogen storage tank and into the compartment and for transporting hydrogen gas out of the compartment, and means for distributing heat within the compartment so as to establish a substantially uniform temperature in the storage media within the compartment; generating a look-up table derived from a series of plots relating changes in pressure of the hydrogen gas in the hydrogen storage tank versus fill levels of hydrogen in the hydrogen storage tank as a function of temperature; filling the hydrogen storage tank to full capacity by flowing hydrogen gas through the passages and into the compartment so as to adsorb hydrogen on the storage media; causing hydrogen release from the storage media for a time period during which there is a substantially constant demand on the hydrogen storage tank; measuring a change in pressure of the hydrogen gas released from the storage media during the time period; and then applying the look-up table to determine the hydrogen fill level in the hydrogen storage tank.