WO2010062251A1

WO2010062251A1 - Power source comprising fuel cells

Info

Publication number: WO2010062251A1
Application number: PCT/SE2009/051339
Authority: WO
Inventors: Anders Lundblad; Björn WESTERHOLM
Original assignee: Myfc Ab
Priority date: 2008-11-26
Filing date: 2009-11-26
Publication date: 2010-06-03

Abstract

The invention relates to a power source (1) for portable electronic devices. It comprises a control unit (CU) responsive to changes in fuel cell performance and adapted to momentarily stop or decrease the fuel cell current for a period of time in case of a malfunction. There is also provided a pressure release valve (56) at the exit of the fuel cell unit (11), said valve being adapted to open in response to an increased pressure inside the fuel cell unit. A flow restrictor (FR) is coupled between the fuel source and the fuel cell unit (11) adapted to provide a pressure within the fuel cell unit during normal operation that is lower than the opening pressure for the valve.

Description

POWER SOURCE COMPRISING FUEL CELLS

The present invention relates to apparatus for delivering electrical power primarily to portable electronic equipment. In particular it relates to such apparatus comprising fuel cells for generating the electric power.

Background of the Invention

Today portable electronic equipment of various types are very common. Examples are computers, music players, telephones just to mention a few.

Most of these devices are provided with some kind of battery for the supply of energy. Some devices have chargeable batteries, which normally are charged by connecting the device to the grid via a so called adapter that transforms the AC voltage from e.g. 220 V to DC and to the level for which the battery is adapted, say 3,6 V.

Of course this requires access to the grid when the battery needs charging, which is not always the case, for example during hiking or in remote rural areas.

In other situations charging is strictly forbidden, such as during air flights due to the potential explosion risk associated with Li batteries. Electronic equipment can be used on an airplane but if the power runs low, it is not allowed to recharge the battery.

There are systems in the prior art such as US 2007/0072042 Al "Portable fuel cell power source" for powering an electronic application device. This patent addresses the above problems, by providing a multi-functionality, i.e. a rechargeable battery that can be connected to the grid, to a DC source or to a fuel cell system.

However, this system still relies on a battery to be recharged when running low on power. Thus, it may still be unusable e.g. during air flights. In PC/SE2008/050932 there is disclosed fuel cell system having a sensor cell.

The fuel cell device is supplied with a pressurized gas, i.e. the fuel feed is designed to reach a certain pressure, when not exceeding its max-flow limit. In this system there is an on/off valve (dead-end valve) at the gas outlet of the fuel cell device. Said valve should be opened for purging out air during start-up of the fuel cell device and also when running due to accumulation of non-fuel gases (e.g. water vapor and N2). By placing a sensor cell after the fuel cells in the gas flow direction but before the dead end valve, the sensor cell can be used during start-up to determine when the concentration of hydrogen has reached acceptable level and thus the dead-end valve can be closed. When running the fuel cell the sensor cell can determine when the concentration of hydrogen has decreased to low and purging is required.

The sensor cell can be implemented for control purposes in a number of different devices.

Summary of the Invention In view of the discussion above, there is still room for improvement of the prior art devices.

Therefore, the present invention in one aspect seeks to provide a power source for electronic devices comprising a control unit (CU) responsive to changes in fuel cell performance and adapted to momentarily stop or decrease the fuel cell current for a period of time in case of a malfunction. It also comprises a pressure release valve (56) at the exit of the fuel cell unit (1 1), said valve being adapted to open in response to an increased pressure inside the fuel cell unit. A flow restrictor (FR) is coupled between the fuel source and the fuel cell unit (1 1) adapted to provide a pressure within the fuel cell unit during normal operation that is lower than the opening pressure for the valve.

The power source according to the invention is defined in claim 1. In a further aspect the invention provides a modular design of a power source.

Thus, the invention provides a modular power source for portable electronic devices, the power source comprising, a main body, a grid connector provided on the main body and comprising power transforming electronics, for enabling charging of a battery (or a supercapacitor) provided in an electronic device, or for direct powering of the device, by-passing the battery, a fuel cell unit capable of delivering electric power when grid voltage is not available, means for accommodating a fuel tank for said fuel cell unit. This aspect is defined in claim 10.

In still a further aspect the invention provides a system for providing electric power to an electronic device, comprising an electric power relay connector member adapted to replace a battery in an electronic device, a power source according to the invention, and means for connecting the power source to the electric power relay connector member. This aspect is defined in claim 16.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus not to be considered limiting on the present invention, and wherein

Fig. 1 is a perspective view of a modular power source according to an embodiment of the invention; and

Fig. 2 illustrates the connector element replacing a battery for supplying electricity directly to a mobile phone;

Fig. 3 illustrates schematically a system having a semi-automatic switch- on/ switch-off valve;

Fig. 4 illustrates a start-up sequence in the operation of the power source according to the invention; Fig. 5 illustrates a situation where the system is at "steady-state", i.e. running at constant power;

Fig. 6 illustrates a conditioning sequence in the operation of the power source according to the invention;

Fig. 7 illustrates a shut-down sequence in the operation of the power source according to the invention.

Fig. 8 shows a "large system" comprising 4 fuel cell assemblies, each provided with a flow restrictor and a pressure release valve in accordance with the present invention;

Detailed Description of Preferred Embodiments The present invention in a first aspect relates to a power source for electronic devices comprising a control unit (CU) responsive to changes in fuel cell performance and adapted to momentarily stop or decrease the fuel cell current for a period of time in case of a malfunction. It also comprises a pressure release valve (56) at the exit of the fuel cell unit (1 1), said valve being adapted to open in response to an increased pressure inside the fuel cell unit. A flow restrictor (FR) is coupled between the fuel source and the fuel cell unit (11) adapted to provide a pressure within the fuel cell unit during normal operation that is lower than the opening pressure for the valve.

In a further aspect there is provided a modular design of a power source for portable electronic equipment. It is modular in the sense that it comprises exchangeable components, either components that have been used and need replacement (e.g. batteries, fuel tanks etc.) or components that can be substituted for other components having a different function.

The modular design can also be seen in that the power source itself comprises several units that can deliver electric power by different means. Preferably the power source comprises a grid connector for enabling charging of a battery provided in an electronic device, or for direct powering of the device, preferably by-passing the battery (e.g. in lap-top computers). Furthermore there is provided a fuel cell unit that is capable of delivering electric power when grid voltage is not available. It can also comprise a chargeable battery, that can deliver electricity when neither grid nor fuel to the fuel cell unit is available.

In a further aspect the invention provides a combination of the power source and an adapter, herein designated "electric power relay connector", for a portable electronic device, such connector replacing a rechargeable battery, and simulating the presence thereof in the device. In this way the device will recognize the connector as the battery, i.e. the connector will be a "dummy battery". Preferably it will have the same geometric configuration as the battery, such that it fits exactly in the device in the battery slot. When the power source according to the invention is connected to this connector, the device will be supplied with electric power from the power source, but will recognise the connector as a battery. In this way it will become possible to use e.g. a mobile phone during air flights without recharging the battery, or to use the phone in remote locations were recharging is not possible.

Suitably all connections between power source and the electronic device is a USB type connector, although other types of connectors of course are possible.

For the fuel cell aspect, the fuel tanks are of a "clip-on" type, i.e. preferably attachable to the device by means of a snap-fit type coupling or by some other position locking means, such as a "rail and recess" configuration.

As an example of exchangeable parts having different functions one can mention different standards of actual grid connectors, for Europe, USA, and other countries. These grid connector members are suitably attachable by a snap-fit type coupling or by a "rail and recess" configuration.

The invention will now be described in more detail with reference to the drawings. Any reference to up or down or similar expressions will refer to the orientation in the drawing figures.

In Fig. 1 there is shown a modular power source, generally designated with reference numeral 1. It comprises a main body 10 in which there is provided a fuel cell unit 1 1 , located beneath a net structure on the top surface of the main body, control electronics (not shown), a USB output port 12, a grid connector 13. Also shown is a clip-on fuel tank 14, which can easily be detached and replaced with a fresh tank.

The fuel tank 14 can be of the well known metal hydride type. It is also possible to provide a hydrogen generator for supply of fuel. Such generators are also well known, and are based on a chemical generation of hydrogen by hydrolytic action.

In Fig. 1 there is also shown replaceable grid connectors 15, 16, one for the US market, denoted 15, and one for Europe, denoted 16.

The main body 10 has a conventional shape, resembling standard type chargers (grid adapters) for electronic equipment, with the difference that it is designed with a recess (or cut-away portion) so as to accommodate a fuel tank 14 in a clip-on connection. When said fuel tank 14 is in operative position, the entire power source will have an outer shape and size very similar to that of the mentioned standard type chargers.

The replaceable grid connector members 15, 16 in the shown embodiment are also provided with clip-on connectors, namely a rim or rail 18 on the connector and a mating recess 19 on the main body 10. As can be seen the rim and the recess have mating trapezoid geometries such that it is possible to slide the connectors in place from the side. The friction between rim and recess is adapted such that the connector will not easily come off the main body. Of course the rim and recess can be provided in a reverse fashion, i.e. the rim being provided on the main body and the recess on the connector. Any other suitable means of connecting is of course equally possible, such as conventional snap-fit locking means.

In the embodiment shown in Fig. 1 the means for attaching the fuel tank 14 comprises mating rims (on the main body, not shown in Fig. 1) and recesses 17 on the tank, similar to those provided on the grid connector members, such that the tank can be slid on to the main body as indicated by the arrow in Fig. 1. Of course the rim and recess can be provided in a reverse fashion, i.e. the rim being provided on the tank and the recess on the main body.

Furthermore, of course it is possible to provide other kinds of attachments for a fuel tank, i.e. a snap-fit type locking, and the skilled man would be able to design different types of attachment without inventive work.

Beneath the top surface of the main body there is provided a micro-fuel cell assembly. The top surface is air permeable to provide access for atmospheric oxygen to the fuel cells. In the shown embodiment the top surface has a net like configuration, but other structures are possible, such as porous materials, perforated structures etcetera, which the skilled man can provide without inventive work.

The fuel cells are suitably of a type disclosed in applicants own previously filed patent applications WO 2006/041397 and WO 2007/ 1 17212, the disclosures of which are incorporated herein in their entirety. These applications relate to so called air breathing polymer electrolyte fuel cells in planar configuration.

In particular WO 2006/041397 discloses the design and construction of fuel cells suitable for the type of application the present invention relates to, and therefore details of the fuel cells will not be described herein.

The main feature of such fuel cells is that they are extremely thin since all components, such as support members, Membrane Electrode Assemblies (MEA), Gas Diffusion Layers (GDL) and other components are built up from sheet or foil materials. Fig 2 illustrates schematically the relay connector 20 or "dummy battery" according to the invention, in an embodiment adapted for a mobile phone.

It comprises an element 20, which in the shown embodiment in principle has an identical geometric configuration to that of a rechargeable battery for e.g. a mobile phone, and therefore fits precisely in the battery slot 22 of the telephone 23 (or other device) in question. When properly positioned in the device, the power source according to the invention can now be connected and begin to deliver electric power. The device (e.g. a telephone) will experience the situation as normal, i.e. being provided with electricity from a battery located in the battery slot. However, the element 20 could exhibit any shape as long as it will be experienced as a proper battery by the device in which it is mounted.

Thus, in operation the connector element acts as a "relay" of electric power from the power source.

The relay connector element 20 may comprise electronic components, such as a processor or other electronic circuitry and sensors, enabling the phone (or other device) to recognize it as a real battery. Optionally, the required electronic components can be located, at least in part, exterior of the connector element, e.g. in the power source to which it is coupled.

Suitably the connector 20 is provided as a "stand-alone" device, since it should be placed inside the device (e.g. telephone) and the device will be closed. Thus, the power source will be connected to the device at its normal power input on the device with a cable 24 having the particular manufacturers connector at one end and a USB connector 26 at the other, for connecting to the power source, as shown in Fig. 2.

The USB standard operation voltage is 4,75 - 5,25 V. However, for the delivery of energy to e.g. a mobile phone, the voltage should be 3,7 V. Therefore, in one embodiment the relay connector 20 comprises a DC/DC converter for converting the voltage to the required 3,7 V. Another possibility within the inventive concept is that the power source will recognize a relay element when it is connected and automatically set the output voltage to 3,7 V. This would of course require some additional electronics within the power source itself.

In a further variant the nominal output voltage of the power source could be set to 3,7 V.

Finally, in a further embodiment the power source could be provided with two connector outputs, one for 3,7 V, the other for e.g. 5 V, i.e. standard USB voltage.

For a device as disclosed above, there could be provided an electro-mechanical valve (EMV) for controlling the flow of fuel to the fuel cells. EMVs of this type are known in the art and the skilled man would be able to select an appropriate one without inventive work.

Preferably, the EMV should be of a type that is manually opened and electromechanically closed. While being open there should be no additional electrical power required to keep it open. Equally after closing there should be no additional force required to keep it closed. One valve having a such design is an o-ring sealing seat being closed by a spring force. When opening there is a snap or hook which keeps the valve in the open position when running the fuel cell, said hook or snap is then released by an electromechanical actuator movement in order to close the valve, said actuator could be a coil mechanism, a piezo mechanism, a bimetal mechanism or other mechanism.

Fig. 3 schematically illustrates one embodiment of a system 40 comprising a valve that can be manually operable or electro-mechanically operable, or a combination of both.

This system can be used for a charger (i.e. a power source), but can also be used as integrated in e.g. a mobile phone or a lap-top computer. The components of the device of Fig. 3 are a fuel tank 42 for e.g. hydrogen or a hydrogen generator, a connector means 44 for connecting the tank to the fuel cells, an electro-mechanical valve (EMV) 46, a fuel cell assembly 48 comprising a number of fuel cells FC 50 a flow restrictor FR 52, a sensor cell SC 54 and a purge valve PV 56, preferably a pressure release valve PRV. There is also shown schematically a control electronics unit (CU). According to the invention this purge valve is a pressure release valve PRV, in which case a flow restrictor FR is required.

The "flow restrictor" in a preferred embodiment is a constriction in the gas flow passage, that can be fixed or variable. Any other kind of "flow restrictor" that meets the requirement is of course possible. In an exemplary embodiment the pressure in the fuel tank is 3 psi, and the flow restrictor brings about a pressure drop of about 2 psi, such that the pressure prevailing inside the fuel cell unit is about 1 psi during normal operation.

A pressure release valve is a passive valve in that it is controlled by the pressure prevailing. It is simple and therefore cheap. A suitable type of pressure release valve is a so called umbrella valve.

A sensor cell suitable for use herein is disclosed in applicants own patent application PCT/SE2008/050932, the disclosure of which is incorporated herein in its entirety.

The pressure release valve 46 is closed in a non-operating state of the fuel cell device, and is manually opened at start-up, e.g. by pressing a button down, so as to let hydrogen gas pass from the tank 42 and into the fuel cell assembly FC.

The tank 42 exhibits an overpressure of about 3-5 psi during operation and delivers a hydrogen flow of about 25 ml ¹.

The passive pressure release valve PRV is set such that the opening pressure is lower than the pressure in the tank (P_pUr_ge < Ptank), and thus it immediately opens when gas begins to flow through the system. As soon as the fuel cells start to operate the pressure drops in the fuel cells and the pressure release valve closes.

Also, in the case of a malfunction that causes the control unit to momentarily stop the current draw from the fuel cell, the pressure will increase and the pressure release valve will open, so as to bring about a purging of the system.

The sensor cell functions to monitor the concentration of hydrogen gas in the system after the last cell. In the event that too little hydrogen gas is available to the sensor cell, the sensor cell voltage will decrease below a threshold level, and in response to this decrease in sensor cell output voltage the sensor cell will indicate LOW. This will trigger the electronics to momentarily stop (or decrease) the fuel cell current for a short moment. This in turn causes a pressure increase in the fuel cells, whereby the pressure release valve opens and the system is purged with gas, and the fuel cells will begin operating again. For example if too much moisture collects in the cells, this function may become operative, and the purging will rid the system of any excess moisture.

This procedure of shutting down and purging is referred to as a "conditioning". The duration of such a conditioning procedure is normally < 1 second.

On closing down of the device, the EMV can be manually closed. However, it is preferred that the valve has an electro-mechanical valve functionality, such that it can be closed electrically by the control system.

Closing down can either occur when the device is disconnected from the apparatus to which it has delivered power, or in a failure situation, where the control system has detected some deviation from normal operation.

Now the operation of the power source will be described in more detail with reference to the schematic illustrations in figs. 4-7. The operation will be given in regard of a system as schematically shown in Fig. 3.

In Scheme A below there is shown a matrix in which letters A-J designate the state of a system at a given point in time for the different functions/ components of the system, during an entire operating cycle from an inoperative state, via start-up, running and until shut-down. The pressures given in Scheme A are only indicative, and are given for the better understanding of the working principles, and should not be taken as limiting on the scope of the invention as claimed.

Each stage will now be described in more detail with reference to the figures beginning with Start-up, Fig. 4.

If the power source is kept without the fuel tank attached, the first operation will be to connect a fresh tank (A). The system is now in stand-by. Next the EMV between tank and fuel cell unit is opened, possibly manually, but if an electromechanical valve is used, opening could be triggered by electric power, by pressing a dedicated start button.

Opening the EMV will generate a pressure wave due to the gas flowing from the tank. This pressure wave will have such magnitude that the pressure release valve PRV will open (B).

SCHEME A

f

*0=open, C=closed, R=running, H=high, L=low, X=unknown gas composition

A short time (e.g. 0,5-2 s) after the valve is opened hydrogen reaches the sensor cell SC, which immediately begins to generate electricity and will indicate "HIGH", i.e. a high voltage (C). A "HIGH" signal from the sensor cell triggers a power draw corresponding to e.g. 25 ml/min, and 2,5 W fuel cell output power, and will start the power source unit output (D).

When the power source has begun operating some different situations can occur.

Namely, the external power draw can be higher than 2,5 W, in which case the system will increase the output from the power source so that the battery is not discharged.

If the external power draw is less than 2,5 W but the battery level is low, the fuel cell output is maintained until the battery level is again normal.

Finally, if the power draw is less than 2,5 W and the battery level is proper, the fuel cell power is adjusted/ decreased to match the external power draw.

The system has now reached a "steady-state" running at constant power (E), e.g. 2,5 W, as shown in Fig. 5.

Fig. 6 shows a situation where conditioning of the system is required.

The Power source unit (PSU) is running at constant power. If for some reason the voltage output from the sensor cell SC becomes "low" (F), i.e. the voltage drops below a predetermined threshold value, e.g. 0, 15 V, the following will happen.

The fuel cell power draw is momentarily decreased or turned off (G) for a very short period of time, e.g. 100ms. The battery immediately compensates for this drop in fuel cell power such that the power output from the power source remains constant. Thereby, there will be a pressure build-up due to the supply of hydrogen that is not consumed, and this will cause the pressure release valve to open and the system is flushed. Normally such drop in sensor cell voltage is indicative of excess moisture or other non-reactive components in the fuel cell unit, and the purging will rid the system of such moisture. It could also be due to the power draw being higher than the available hydrogen flow, thus leading to vacuum and a back-flow through the pressure release valve.

If after restart of the fuel cell unit the sensor cell SC indicates "HIGH" again, the power source will continue running as before (H).

However, if the sensor cell still indicates "LOW" after restart, the fuel cell unit will be stopped again and restarted at a lower power draw, e.g. 10% lower. Thereby the battery will compensate so that the output from the power source remains constant. This will of course drain the battery and when the system indicates low battery level, the power source is turned off relative to the external equipment, and internal charging will be initiated. After said charging of the battery the power source unit is restarted again so as to deliver output power.

System shut-down will now be described with reference to Fig. 7.

The power source unit runs at constant power.

Either the user decides to switch off the unit because he or she has finished using the device being powered, or the systems control electronics has decided, for some reason or another, to shut down the power source unit.

Possible reasons for automatic shutdown could be too low power demand or too high (battery runs low). In such cases output power is interrupted momentarily. Thereafter the power draw from the fuel cell is decreased slowly and the battery is charged to avoid high pressure peaks from the hydrogen source (I).

When the fuel cell unit is shut down a current pulse is delivered to the electromechanical valve EMV so that it is closed. When the valve has been closed the hydrogen remaining in the anode compartments is consumed by periodically short circuiting the fuel cell until the open circuit voltage is below 1 V or any cell is below 0 V (J).

In another embodiment the invention is implemented in a larger system, as schematically illustrated in Fig 8. Such a system can consist of several fuel cell assemblies (e.g. 4 assemblies) connected in parallel to the fuel source, each assembly having several individual cells (e.g. 4 cells) and a flow restrictor FR and a pressure release valve PRV. Preferably the assemblies should also have a sensor cell SC. Each assembly can also be electrically connected to an individual DC/ DC-converter as illustrated in Fig 8.

Claims

CLAIMS:

1. A power source unit (1) for providing electric power to an electronic device, comprising a fuel cell unit (11) and a source (14) of gaseous fuel, characterized by a control unit (CU) responsive to changes in fuel cell performance and adapted to momentarily stop or decrease the fuel cell current for a period of time in case of a malfunction; a pressure release valve (56) at the exit of the fuel cell unit (1 1), said valve being adapted to open in response to an increased pressure inside the fuel cell unit; and a flow restrictor (FR) coupled between the fuel source and the fuel cell unit (1 1) adapted to provide a pressure within the fuel cell unit during normal operation that is lower than the opening pressure for the valve.

2. The power source unit as claimed in claim 1 , further comprising a sensor cell (SC) in the fuel cell unit (1) coupled to the control unit (CU), the sensor cell being responsive to changes in the hydrogen gas concentration at the exit of the fuel cell unit (1), wherein the change in cell voltage of the sensor cell is indicative of the change in hydrogen gas concentration.

3. The power source unit as claimed in claim 2, wherein the control unit (CU) is coupled to the sensor cell (SC) and is responsive to the cell voltage of the sensor cell.

4. The power source unit as claimed in claim 1, wherein the pressure release valve (56) is adapted to open at a pressure that is lower than the pressure in the fuel source (14)

5. The power source unit as claimed in claim 4, wherein the valve (56) is a pressure release valve of the umbrella type.

6. The power source unit as claimed in claim 1 , wherein the flow restrictor is a constriction in the gas flow passage.

7. The power source unit as claimed in claim 6, wherein the flow restrictor is fixed.

8. The power source unit as claimed in claim 6, wherein the flow restrictor is variable.

9. The power source unit as claimed in any preceding claim, which is a charger.

10. A modular power source (1) for portable electronic devices, comprising:

a main body (10);

a grid connector (13; 15; 16) provided on the main body (10) and comprising power transforming electronics, for enabling charging of a battery provided in an electronic device, or for direct powering of the device, by-passing the battery;

a power source as claimed in claim 1 , capable of delivering electric power when grid voltage is not available;

means (17) for accommodating a fuel tank (14) for said fuel cell unit (11).

1 1. The power source as claimed in claim 10, further comprising a chargeable battery, that can deliver electricity when neither grid voltage nor fuel to the fuel cell unit is available.

12. The power source as claimed in claim 10 or 11 , wherein the grid connector (13; 15; 16) is a replaceable member.

13. The power source as claimed in claim 12, wherein the fuel cell unit comprises air breathing polymer electrolyte fuel cells in planar configuration.

14. The power source as claimed in any of claims 10-13, comprising a clip-on fuel tank (14).

15. The power source as claimed in any of claims 10-14, further comprising a slot for accommodating a rechargeable battery, that can be charged by the power source, and that can deliver electric power if neither grid nor fuel cells are operable.

16. A system for providing electric power to an electronic device, comprising

an electric power relay connector member (20) adapted to replace a battery in an electronic device;

a power source unit (1) as claimed in claim 1; and

means (24, 26) for connecting the power source to the electric power relay connector member (20).

17. A system for providing electric power to an electronic device, comprising

a power source unit (1) as claimed in claim 1 , comprising:

- a main body (10); - a grid connector (13; 15; 16) provided on the main body (10) and comprising power transforming electronics, for enabling charging of a battery provided in an electronic device, or for direct powering of the device, by-passing the battery;

- a fuel cell unit (11); - means (17) for accommodating a fuel tank (14) for said fuel cell unit

(H);

characterized in that

said fuel cell unit is an air breathing polymer electrolyte fuel cell unit (11) in a planar configuration capable of delivering electric power when grid voltage is not available; and in that the system further comprises:

an electric power relay connector member (20) adapted to i) replace a battery in an electronic device, ii) to simulate the presence of a battery in said electronic device, and iii) to relay current from the power source to the electronic device; and

18. A system for providing electric power to an electronic device, comprising

a power source unit (1) as claimed in claim 1 , comprising: - a main body (10);

- a grid connector (13; 15; 16) provided on the main body (10) and comprising power transforming electronics, for enabling charging of a battery provided in an electronic device, or for direct powering of the device, by-passing the battery; - an air breathing polymer electrolyte fuel cell unit (11) in a planar configuration and capable of delivering electric power when grid voltage is not available;

- means (17) for accommodating a fuel tank (14) for said fuel cell unit

(H);

an electric power relay connector member (20) adapted to replace a battery in an electronic device, so as to simulate the presence of a battery in said electronic device, for relaying current from the power source to the electronic device; and

means (24, 26) for connecting the power source to said electric power relay connector member (20).