My eldest son works in Rotterdam II port where he runs the section responsible for the servicing of the electric vehicles which transfer containers from the ships to the waiting trucks and vice versa.
The vehicles have a conventional lead acid battery pack which weighs 12 tonnes. They can carry two 30 tonne containers, and when fully laden the whole rig weighs around 100 tonnes. Their maximum speed fully laden is around 30kph. They are working more or less continuously and typically they need to visit the battery section every 8 hours to have their depleted batteries removed and a new pack fitted. The whole procedure is entirely automatic, as this, as well as the vehicles' loading/unloading schedule is computer controlled, and the vehicles are driverless.
I'm not sure how relevant all this to military operations, but I only post it as it indicates what can be achieved with even conventional battery powered vehicles.