Two Minutes for an Extra 185 Miles. How’s That for a Power Bank on Wheels?

When your smartphone runs low and there’s no charger in sight, you just hook up a power bank and carry on. The same idea, it turns out, can be scaled up for EVs—and someone has decided to make it a reality. It’s not the first attempt at this concept, of course, but the real challenge is making such a system convenient for drivers and financially viable for whoever operates it.

A French startup called Far-a-day offers its own take on the idea. If you need extra range while on the road, you’ll be able—at least in theory, once the app actually works—to request a small trailer equipped with its own battery pack.

The unit is about 1.3 meters long, weighs roughly half a ton, and carries a 60-kWh battery. According to the company, that’s enough to add around 300 kilometers (185 miles) of range. They claim the hook-up process takes roughly two minutes, and judging by their promo video, the car continues charging even as it moves.

Naturally, there are some big questions. First, will different EV models actually allow power delivery from an external source while driving, even with a special adapter? Second, how many people are willing to install a dedicated tow hitch that costs around €600 ($650)? And third, how dense and reliable will the rental network of these battery trailers really be?

Far-a-day says it hopes to open roughly thirty stations across France. Based on early estimates, the charging service itself could run between €18 and €42 ($19–$46), not including the rental fee for the trailer. That might be acceptable for a one-off “emergency” top-up when you’re too far from a charging station. Relying on it regularly, however, could get expensive—so why invest in an expensive hitch unless you plan to use it often?

For now, the true demand—and therefore the survival—of the project remains unclear. Still, the startup aims to launch in 2026, which isn’t far off.