Method and system for charging a battery wherein the internal pressure varies depending on state of charge and temperature

The process involves adjusting charging current with respect to a preset current set point as long as internal pressure of a battery e.g. nickel metal hydride battery, is lower than a preset threshold, in a battery charging phase. The value of the current set point is chosen to be greater than the value of a low charging current. A voltage is adjusted with respect to a preset voltage set point in a final charging phase. An independent claim is also included for a battery charging system.