If you mean this tiny little 9V batteries used in tv-remotes or in radio-clocks: Forget it!
AFAIK the best way is a motorcycle battery with at least 5 to 10 Ah.
The FF400 needs 12 Watt, that means 1 A at 12 Volts, this is 5 to 10 hours of operating with aforementioned motorcycle battery, so go figure...:-)

Regards
Zapp

Any laptop with 6 or 9 pin FireWire port will provide power for the fireface 400.

All MacBook Pro's will work, along with most regular MacBook laptops as well.

In the PC world things don't really work that way in portables, so car battery it is...

If you require operation for a couple of hours, there are rechargeable Li-Ion battery packs (which are sometimes sold as laptop re-chargers) that have adjustable output voltage that will do this job.  I have a pair made by Medion whicb I have used to power the FF400 and QuadMic.  A bit more elegant than a motorcycle battery, but not quite the endurance.

The QuadMic also came with a cable to be plugged into a car "cigarette lighter" outlet.  Maybe you can source one of these from RME - if that would help.

Oooo! That looks like a decent option!

I am thinking of trying the standalone FF400 mode. The FF400 output will be going into the Olympus LS11 line in.
So laptop use is optional.

I am not sure however whether the preamplified analog signal is going though the FF400 AD/DA, a step which will be done in LS.

Thanks again

Je parle Francais comme une vache espagnol.  Ik spreek Nederlands kleine bitje.  Dommenschnitt!  Lets stick to english ... I can understand other people's English better than they can understand my French.  (And Google Translate fills in some gaps ... rotfl )

I was not correct.  The brand is Tevion Computing ('a registered trademark of ALDI stores', for whom Medion is often their technology provider).  It is called a "Portable Battery Pack" and the Model Number is ABS-102.  It has a Li-Ion battery inside with a quoted capacity of 32WattHours.  It will produce output voltages of 3,3V, 5V, 6V, 7.5V 9V, 12V and 16V, with a rating of 2A between 7.5V and 12V.  The FF400 is rated for 1A at 12V, so in theory (!) it would provide 12V for at least 2.5 hours.  For a QuadMic, it would last about 8 hours (depending on phantom power, etc.)

I bought these units 4 years ago, so maybe the product is no longer available, but maybe it has been replaced by a new/'better' unit. And Aldi usually source their "special products" from commercial production lines.  I would think that similar products are still available in Paris ..

If you are wanting to use a UFX, that is a very different question.  As the UFX only accepts 110/230VAC, you need a UPS or a 12 battery with an inverter that turns 12VDC into 230V AC.  I have been thinking about this for myself, because up until now, all my recording gear can work from its own batteries or DC (without mains).  My new remote recording rig (UFX plus BG2) is purely mains powered.  For critical work I need a power supply that cannot be interrupted (by someone tripping over the power cord or blowing the fuse).  Or, I revert to the FF400, QuadMic, etc.

Bonne chance!

Same appearance, specifications slightly different (maybe they have improved the Li-Ion battery).

Thanks for the link - it may be useful in future.