What kind of electric cargo bike?
Surley's Big Easy. A longtail cargo bike (400lbs load limit). Images below of it loaded with the 5x7 for the first exploration (25 mile ride, about 2/3 single track, 1/3 dirt and paved road). Had the camera in a side pannier, but too big a risk of whacking it against a tree, then I put the camera pack on top rack, with tripod on the side...better and easier access.
Pedal assist only (no throttle)...if you don't pedal, you do not go anywhere. Two batteries...range can be stretched to 150 miles or so with slower travel (Eco Mode) and more pedaling...practical use: putting it in Turbo to get up hills and keeping it on Tour for the rest and the speed at about 15 mph, maybe 75 miles. Depends on weight, wind, terrain, tire pressure and so on. At 20 mph, the motor shuts off and you are on your own.
Heavy bike -- steel frame and steel fork. Solid machine. Made in MN, I believe, motor from Germany. Riding it loaded and on hilly ground, the effort I have to put out would be equal to riding a light bike on flat ground. It is not a free ride...but almost an E Ticket ride.
PS -- I have been off the bike for any long rides for a few weeks -- bad elbow partly due to handle bars of the bike. After 300 miles on it (takes awhile for pain to sink into my brain) I realized that the angle of my wrist and elbows were all wrong. I have since bought and installed new stem and bars, and waiting for the elbow to behave itself and get out there again. The handle bars are much straighter and now slightly higher than the seat (same height before), which will take weight off the arms. The heavy smoke has curbed my desire to go out and do heavy breathing, so the arm is getting the rest it needs.
PS #2 -- the bike has a Walk Mode...allows you to walk alongside the bike and have it be powered up to 3.5 mph. So it can act as a motorized cart for the camera equipment. I used it a few times on trail sections too steep or rough to ride, but I did not have to supply much of the effort to get a hundred pounds of bike and equipment up the steep rocky hill.
PS #3 -- I sold my car to buy this (still have the campervan).