An energy apparatus having an electrical energy storage functionality and an electrolysis functionality, the system comprising a functional unit, the functional unit comprising: - a first cell, comprising a first cell electrode and one or more first cell openings for a basic first cell aqueous liquid and for a first cell gas, wherein the first electrode comprises an iron based electrode; - a second cell, comprising a second cell electrode and one or more second cell openings for a basic second cell aqueous liquid and for a second cell gas, wherein the second electrode comprises a nickel based electrode; - a separator, wherein the first cell and the second cell share the separator, wherein the separator is configured to block transport of one or more of O 2 and H 2 from one cell to another while having permeability for at least one or more of hydroxide ions (OH -) monovalent sodium (Na +), monovalent lithium (Li +) and monovalent potassium (K +); - a first electrical connection in electrical connection with the first cell electrode, and a second electrical connection in electrical connection with the second cell electrode; the energy apparatus further comprising: - an aqueous liquid control system configured to control introduction of one or more of the first cell aqueous liquid and the second cell aqueous liquid into the functional unit; - a storage system configured to store one or more of the first cell gas and the second cell gas external from said functional unit; - a pressure system configured to control one or more of (a) the pressure of the first cell gas in the functional unit, (b) the pressure of the first cell gas in the storage system, (c) the pressure of the second cell gas in the functional unit, and (d) the pressure of the second cell gas in the storage system; - a charge control unit configured to receive electrical power from an external electrical power source and configured to provide said electrical power to said functional unit during at least part of a charging time at a potential difference between the first cell electrode and the second cell electrode of more than 1.37 V, wherein the energy apparatus is configured to operate in the range of 1.48 to 2.0 V when producing hydrogen; - a first connector unit for functionally coupling to a receiver to be electrically powered and the electrical connection (51,52), and a second connector unit for functionally connecting a device to be provided with one or more of the first cell gas and the second cell gas with said storage system; and - a control system configured to control the aqueous liquid control system, the storage system, the pressure system, and the charge control unit. - a first cell, comprising a first cell electrode and one or more first cell openings for a basic first cell aqueous liquid and for a first cell gas, wherein the first electrode comprises an iron based electrode; - a second cell, comprising a second cell electrode and one or more second cell openings for a basic second cell aqueous liquid and for a second cell gas, wherein the second electrode comprises a nickel based electrode; - a separator, wherein the first cell and the second cell share the separator, wherein the separator is configured to block transport of one or more of O 2 and H 2 from one cell to another while having permeability for at least one or more of hydroxide ions (OH -) monovalent sodium (Na +), monovalent lithium (Li +) and monovalent potassium (K +); - a first electrical connection in electrical connection with the first cell electrode, and a second electrical connection in electrical connection with the second cell electrode; - an aqueous liquid control system configured to control introduction of one or more of the first cell aqueous liquid and the second cell aqueous liquid into the functional unit; - a storage system configured to store one or more of the first cell gas and the second cell gas external from said functional unit; - a pressure system configured to control one or more of (a) the pressure of the first cell gas in the functional unit, (b) the pressure of the first cell gas in the storage system, (c) the pressure of the second cell gas in the functional unit, and (d) the pressure of the second cell gas in the storage system; - a charge control unit configured to receive electrical power from an external electrical power source and configured to provide said electrical power to said functional unit during at least part of a charging time at a potential difference between the first cell electrode and the second cell electrode of more than 1.37 V, wherein the energy apparatus is configured to operate in the range of 1.48 to 2.0 V when producing hydrogen; - a first connector unit for functionally coupling to a receiver to be electrically powered and the electrical connection (51,52), and a second connector unit for functionally connecting a device to be provided with one or more of the first cell gas and the second cell gas with said storage system; and - a control system configured to control the aqueous liquid control system, the storage system, the pressure system, and the charge control unit.