# GMG doubled its battery energy density. The hard part is still unsolved. - Date: 2026-04-15 - Category: Space & Aerospace The 49 Wh/kg figure at six-minute charge is real — but a phone battery stores four times more energy per kilogram. GMG is not targeting your phone. It is targeting the heavy equipment market where a six-minute pit stop beats a one-hour charge and downtime is the enemy. ---