Questions and Answers

On this page you will find all the answers to questions that we are often asked about our new EFOY. If you do not find your answer, do not hesitate to contact us. We will help you!

General Informations
Installation / Operation
Consumption / Fuel Cartridge
Inclination angle
Purchase questions
EFOY COMFORT / new EFOY fuel cell

General Informations

Why do I need an EFOY fuel cell?

The EFOY fuel cell is a fully automated battery charger that is quiet, easy to use and environmentally friendly, operating as a power generator in mobile homes, caravans, boats or cabins.

What is a fuel cell?

The EFOY fuel cell converts chemical energy into electrical energy without any interim stages, moving parts or much loss of efficiency. The underlying principle is an electrochemical process that is also known as "cold combustion". It is in principle the reversal of electrolysis. The EFOY fuel cells are based on DMFC (Direct Methanol Fuel Cell) technology. They generate power by using methanol provided in a fuel cartridge, in combination with oxygen from the air. Methanol is directly converted into power by the fuel cell. By products in the electromechanical process, include waste heat, water vapour and a small amount of carbon dioxide. Thus, a fuel cell is not an energy storage devise but an energy generating devise. For more Information:
Operating principle

How does the EFOY fuel cell work?

The EFOY fuel cell converts the fuel in the fuel cartridge directly into electrical current without any moving parts. Thanks to this direct conversion, the fuel cell operates silently, is environmentally friendly, clean and extremely efficient.

How it works

Can I use the EFOY fuel cell in hybrid operation with a solar energy system?

Yes. A lot of our customers do this. The fuel cell switches on automatically when there is insufficient sun available to charge the batteries.

Why should I buy an EFOY fuel cell when there are solar cells?

Solar energy is a fascinating subject, but solar energy systems only work when the sun shines directly on the solar module, i.e. without any shadowing effects and at the correct angle of incidence. This is not the case in most situations e.g. due to clouds, fog, rain, snowfall, tree shade, nighttime operation etc. Therefore an EFOY fuel cell is a good addition or alternative for those who are on the road the whole year or for those who do not get enough power from the solar cell due to weather conditions or shade.

An energy analysis is easy with our model check

Why should I buy an EFOY fuel cell when there are petrol- or diesel-powered generators?

Generators are very loud and not only disturb your own relaxation but also that of your neighbors. The emissions that they produce cause an unpleasant smell and are harmful to the environment. In contrast, the EFOY is as quiet as a whisper and environmentally friendly – which is good for you and for the environment.

Why should I buy an EFOY fuel cell when modern lithium batteries are available?

Lithium (LiFePO4) batteries have many advantages over lead batteries. They have a high capacity at low weight and can therefore also operate high energy consumers such as coffee machines or hair dryers for longer. Despite their high capacity, they are energy storage devices. This means that even lithium batteries have to be recharged at some point. The EFOY fuel cell is the ideal combination with a lithium battery* and thus offers the complete powerful energy package. EFOY Hybrid Power is a perfectly matched energy package consisting of an EFOY fuel cell as the power generator and an EFOY lithium battery as the power storage device. The smart Battery Management System (BMS) of the EFOY lithium battery ensures intelligent communication between the fuel cell and battery.

*Silver EFOY 600-1200 fuel cells (production year before 2011) are not compatible with lithium batteries

How many fuel cells are in use and are customers satisfied with the EFOY fuel cell?

SFC has already sold more than 45,000 EFOY fuel cells, which are in use day in, day out. The total operating time of all units amounts to over 10 million hours. In a survey of 955 EFOY owners, 93% of those questioned were satisfied with their EFOY fuel cells and would recommend them to other potential customers.

Why are there several models in the EFOY range?

Customers’ performance requirements vary depending on usage profile, personal needs, type and power consumption of the appliance and environmental conditions. EFOY products with varying levels of output offer the customers the choice and opportunity to purchase the fuel cell that matches their needs.

Which EFOY fuel cell matches my needs?

Please have a look at our energy calculator and find out.

energy calculator

Installation / Operation

How is the EFOY installed?

Installation is performed by an authorized dealer, or the unit comes pre-installed with your boat or mobile home.

Dealer search.

What must I watch out for when installing?

Make sure there is an adequate air supply and sufficient ventilation for waste heat and spent air. Please also ensure that there is enough space for the fuel cartridges and the unit itself. You can refer to the User Manual for more details.

Can I retrofit an EFOY fuel cell?

An EFOY fuel cell can be easily installed at any time. It is simply connected directly to a normal battery. Please contact your EFOY dealer for more information.

Do I need an additional charge controller for an EFOY fuel cell?

No. The EFOY incorporates its own charge controller.

Can I connect electrical appliances directly to the EFOY fuel cell?

No. The EFOY fuel cell is a battery charger. Electrical appliances are supplied with power by the battery.

What types of battery can I charge with an EFOY fuel cell?

An EFOY fuel cell is an automatic charger for 12 V lead-gel, AGM, lead-acid or SFC certified Lithium Iron phosphate (LiFePo4)* batteries. The energy package consisting of an EFOY fuel cell and EFOY lithium battery offers even greater convenience.

*Silver EFOY 600-2200 fuel cells (production year before 2011) are not compatible with lithium batteries

Can I charge more than one battery (e.g. 2 x 100Ah)?

Yes. We recommend that 2 x battery capacity is less than the total charging capacity of the EFOY fuel cell.

Can the EFOY also be used to charge a lithium battery?

Yes. The EFOY can be used in combination with lithium iron phosphate batteries (LiFePO4) from selected manufacturers. For an ideal energy package we recommend using the EFOY lithium battery. EFOY Hybrid Power is a perfectly matched energy package consisting of an EFOY fuel cell as the power generator and an EFOY lithium battery as the power storage device. The smart Battery Management System (BMS) of the EFOY lithium battery ensures intelligent communication between the fuel cell and battery.

Is it possible to adjust the switch-on/switch-off thresholds?

Yes. All the fuel cells in the new EFOY series allow the switch thresholds to be adjusted via the EFOY App or the control panel.

Is there a risk that the batteries can be exhaustively discharged?

No. An EFOY fuel cell has a mechanism to prevent exhaustive discharge and will activate even when switched "Sleep" in order to protect the batteries. SFC recommends always operating the EFOY in the automatic mode.

What exhaust gases does an EFOY fuel cell produce?

It produces very small quantities of water and carbon dioxide. An EFOY 80 for example produces as much spent air at peak load as a human breathes out.

How much waste heat is produced?

The level of waste heat depends on the ambient temperature, which is why there is no simple answer to the question. The heat (measured in watts) is approximately three times as high as the electrical energy (rated power) generated by the unit. For example, an EFOY 80 fuel cell produces approximately 120 W of heat.

Does the exhaust air contain just water and CO2?

The exhaust air may also contain traces of methanol and methanol-based waste products. The quantities and concentration of these are below the legal thresholds. WARNING: Always expel exhaust air into the open. Inhaling the exhaust air or drinking the water may be harmful to your health. The exhaust air contains no CO (carbon monoxide) or NOx (nitrogen oxide).

Can an EFOY fuel cell be operated in a moving vehicle?

Yes. The EFOY is approved for use in motor vehicles. Leading vehicle manufacturers install fuel cells in their vehicles as standard.

What should I do in the event of an accident?

Do not switch the fuel cell on. The unit must be returned for inspection to check that it does not leak and that it operates correctly. Please contact the EFOY service team.

Service Request

What safety standards does the EFOY fuel cell meet?

The EFOY fuel cell meets the highest standards of safety and quality, including regulations governing installation in motor vehicles. It is certified in accordance with ECE-R10 (installation and operation in motor vehicles), CE and "Safety-tested and production-monitored fuel cell system" awarded by TÜV SÜD.

Consumption / Fuel Cartridge

How much fuel does the unit consume?

The consumption depends on the power of the fuel cell. An EFOY 80 consumes approx. 40ml methanol per hour, whereas an EFOY 150 needs approx. 75ml.

How long does an M5 or M10 fuel cartridge last on average?

The EFOY fuel cartridge is available in 5 l and 10 l. The consumption is 0.9 l per kWh, so the EFOY Fuel Cell can generate 460 Ah or 925 Ah of electricity at 12 V voltage. Depending on the power consumption, a 10 l methanol fuel cartridge will provide you with a self-sufficient power supply for up to 4 weeks.

How many fuel cartridges will I need in a year?

EFOY customers in mobile homes or boats generally need 2-3 M10 fuel cartridges per year in normal use.

Are EFOY fuel cartridges approved for transportation?

EFOY fuel cartridges were designed to meet the highest safety requirements from the very beginning. Fuel cartridges are also approved and labelled for road, sea and air transport.

Can an EFOY fuel cell be operated with other fuels or fuel cartridges?

No. It is not allowed to use fuels or fuel cartridges other than the original fuel cartridges supplied by SFC Energy AG. CAUTION: Using contaminated methanol will result in damage to the product and invalidate the warranty.

Why is it not possible to refill the fuel cartridges (either myself or through a third party) ?

The law stipulates that EFOY fuel cartridges may only be sold in sealed containers for safety reasons. Accordingly, it is not permissible by law to provide a refill solution. In addition, the costs and energy overhead involved in refilling would not justify the benefits.

How long do fuel cartridges keep?

There is a label on the back of every fuel cartridge indicating its use-by date.

Why does SFC use methanol and not gas or some other form of fuel?

SFC has focused on the proven direct methanol fuel cell. This technology does not require the fuel to be converted into hydrogen in a very complex and elaborate process as is the case with e.g. propane or butane gas. A further advantage is the high energy density of methanol and the use of fuel cartridges as means of storage. One M10 cartridge weighs only 8.4 kg (18.5 lbs) and provides a capacity of 920 Ah (which corresponds to more than 250 kg (550 lbs) of lead batteries).


What is the temperature range in which the fuel cell operates?

We guarantee safe operation in an ambient temperature range of -20 °C to +40 °C (-4° F to +104° F). Should you require a power source to operate under more extreme conditions, please contact [email protected]

Is it possible to run at temperatures below 0°C (32°F)?

Yes. The fuel cell has an intelligent frost protection system, which ensures that it function when used at even very low temperatures.

What happens above +40 °C (104 °F), which is considered to be the maximum temperature?

The unit interrupts the charge function and re- starts automatically once the temperature falls. This prevents damage to the fuel cell. Should you use the fuel cell at high temperatures for long periods of time, please contact [email protected]

Why do you recommend the removal of the fuel cell from vehicles during winter months?

We only recommend removal if you do not require the fuel cell for longer than 2 months (for example in winter storage with a power supply). Removal and frost-free storage can save fuel.

How does the frost protection mode work?

The fuel cell has an intelligent automatic frost-protection system. It keeps itself warm when temperatures fall below 3 °C (37 °F) if it is connected to a functioning battery and has a supply of fuel. The system also works, when the unit is turned off.

How much does the frost protection mode consume?

The fuel cell requires approx. 5-10 litres of methanol for a dedicated frost protection mode during a five-month winter period in Central Europe.

What must I do if the fuel cell freezes?

If the fuel cell freezes despite all precautions, allow it to thaw switched off in a warm environment over a period of approx. 24 hours before putting it into operation. Please note that a fuel cell’s efficiency may decrease when allowed to freeze repeatedly.

Inclination angle

What is the maximum angle of tilt for EFOY fuel cells?

The unit can be operated for a sustained period of time at an angle of tilt of up to 35° longitudinally and up to 35° laterally.

What happens if the fuel cell tilts further than this?

The fuel cell will switch off and will report an error when switched back on again. Please follow the instructions on the display.

Purchase questions

Where can I buy an EFOY fuel cell?

We recommend that you only purchase a fuel cell from authorized EFOY dealers. You can find here a list of the dealers here.

Dealer Search

How much does an EFOY COMFORT fuel cell cost?

Your authorized EFOY dealer provide you with the current price.

What is included in delivery?

Please find the scope of delivery here.

Scope of delivery


Does SFC provide a warranty for the EFOY fuel cell?

The EFOY fuel cell meets the highest quality standards. We guarantee it. For more details go to Warranty.


When does warranty cover start?

The purchase date of the new fuel cell on the invoice and its registration with SFC determine the start of warranty cover.

Why do I have to register?

Registration makes the warranty valid, ensures that we can provide you with the latest information on a regular basis, for example, when a new firmware update is available. In addition, SFC will have all the necessary details if you require service, which means that we can process a case faster.


Can an EFOY fuel cell be repaired if it is defective?

Yes. We can repair your fuel cell at our location in Munich/Brunnthal, Germany and in Calgary, Canada when necessary. For further information please see Service

Is it possible for me to buy replacement parts and install them myself?

No. The unit must never be opened.

How long does a repair take?

Repairs can generally be performed within a few working days. On top of this there is the time required for transportation and the time until the quotation is approved.

How much do repairs cost?

Repair costs depend on the components involved.

Why should I regularly carry out an update?

We recommend that you install a new update. The devices are continuously optimised and you can benefit from these improvements via a firmware update.


Why do I need the service fluid? What is it exactly?

Service fluid is delivered with your EFOY fuel cell. Thanks to SFC’s patented water recovery system, fluid is recovered in a closed circuit. Over a long period of operation with high external temperatures a part of this fluid may evaporate, and the fuel cell will indicate that it requires service fluid. It is recommended to always have a bottle with you. Never fill up more than one bottle, and only when the fuel cell indicates that it really needs it.

EFOY COMFORT / new EFOY fuel cell

Can the new EFOY fuel cell also be operated using the control panel of the EFOY COMFORT?

No. The new EFOY fuel cell can only be operated with the new control panel or the EFOY App.

I have an EFOY COMFORT. Can I use the old cabling?

The charging cable, the waste heat flange and the mounting for the EFOY fuel cell must be replaced. However, these are included in the Scope of delivery for the new EFOY fuel cell. The off-heat tube and exhaust hose, on the other hand, can be used if they are still in good condition.