https://www.mst.com/MSTgroup/litronik

LITRONIK is one of the few providers of compact and ultra-reliable primary batteries for active implants in the world. Since 1990, the company has developed and manufactured these high-performance power supplies in various performance ranges, characterized by, among other things, very high volumetric power and energy densities, rate optimization, low rates self-discharge and high operational safety.

https://axteraerospace.com/

Axter Aerospace is a company focused on the development, design and manufacture of hybrid electric propulsion systems and batteries since 2011.

https://www.drone-hopper.es/

The QUAD HOPPER is a compact multi-rotor drone designed for industrial support and automated parcel transport. It is capable of carrying heavy sensors during long flight times, as well as delivering light cargo over short and medium distances. It is designed with a wide range of redundancies to ensure mission integrity. This includes a 3x redundant autopilot and a 4-engine linked propulsion configuration.