Japan's Arma electric scooter with swappable battery folds smaller than a briefcase

Folding electric scooters are designed to fit into a backpack or even a backpack, but Japanese personal mobility device company Shimizu has aspirations of going "smaller." The company is currently refining a prototype that it claims will be the world's smallest and lightest electric car. While we can't yet claim that it's the world's smallest and lightest electric vehicle, the Arma Folding Bike certainly impresses at just 10 pounds (4.5kg).

This "last mile transport" quickly packs down to the length and width of a sheet of printer paper and fits into a messenger bag or daypack... or can be carried around like a briefcase with its built-in handles.

The Arma is a very convenient tool for urban commuting, especially when taking it with you on public transportation, up high-rise office or apartment buildings, and into retail stores. In addition, Arma has a feature that is rare on folding electric motorcycles of all sizes: a battery-replaceable platform that allows users to quickly replace new batteries.

Shimizu estimates that each 3.5 Ah 36-volt lithium battery will give the 250-watt motor 7 to 9 miles (11 to 14.5 kilometers) of range, but Arma is still in the prototype stage and final specifications may change. Top speed is expected to be 14.9 mph (24 km/h). The battery is located in the central body shell that connects the scooter's steering tube and foot pedals. It can be quickly charged via USB-C port, and the charging time is about two hours.

Unlike the classic single-joint scooter pole/pedal folding mechanism, the Arma uses a multi-joint design that allows it to be packed smaller. Each of the two footrests can be folded around the rear wheel to form the lower half of the box, and then swiveled around the folded front wheel. At the top, the handlebars fold inwards so that the full-length steerer tube folds into three sections at the midsection to form the top of the box. Shimizu says the process takes less than 30 seconds, and hopes it will be faster on the production version.

The packaged Arma measures 210x297 mm (8.3x11.7 inches) in height and width respectively, which is exactly the same size as a sheet of A4 paper (equivalent to US 8.5x11 inches of international printing paper). Of course, at 3.8 inches (96mm) deep when packed down, the Arma is certainly much thicker than paper, but still compact enough to fit in a backpack, laptop bag, briefcase, or handbag. It weighs just 10 pounds (4.5 kg), so even with a spare battery or two in for extra range, it's not bulky.

The Arma's handlebars have a gas and brake buttons, as well as a central display that shows metrics like speed and battery life. It can support riders up to 220 lbs (100 kg).