The EMILY 65W fuel cell in the 0.9 t Mercedes (Wulf)

The EMILY was specially designed for use in military all-terrain vehicles. It will generate power reliably even if the vehicle has been driving in rough terrain for some time.

Example:

Mercedes G-Model, also known as the "Wulf"
The EMILY was connected to the radio batteries in this vehicle. 

The many advantages:

• Fully automatic – When the engine’s off, the fuel cell’s built-in automatic regulator continually monitors the batteries’ voltage level. Should it dip below a predetermined threshold, the EMILY cuts in to recharge the batteries, thus assuring that they will always be fully charged. This frees up the vehicle for maneuvers.
• No more drained batteries – Since the batteries can no longer go completely dead, the EMILY eliminates the problem of drained radio batteries, thus prolonging their life considerably.
• Operates several electrical devices at once – Acting through the battery, one EMILY can run two new radios (such as the SEM 93), the vehicle’s GPS, and a computer, even though the engine is not running.

The EMILY can supply any and all technical devices on board a military vehicle with current quietly, reliably, and continually.