Charging electric car batteries with “portable” battery packs

Hello everybody,
I would like to ask you an opinion about this idea I am working on in the last period, most of all I am not completely sure about the technical feasibility of it, so any information from you is precious for me!!
The idea is very simple: in case an electric car runs out of battery in a place in which there is no charging station, I would like to have some kind of portable battery pack which I can plug into the electric car for some hours, so that it can charge it again and make it move. In order to do it I would need:
[li]A battery pack with a standard plug so that it can be capable of recharging the highest number of electric cars
[/li][li]A VAN or a pick-up in which I can load and unload the portable battery pack, so that I can leave the battery pack in charge until it comes the moment in which I need it

I sounds to me like something possible, like when a laptop PC recharge a smartphone through USB cable: it is a battery (the laptop one) recharging another one (the smartphone one). I know that electric car batteries have pretty big size and weight, so I would like to understand better how can it work and in case how many portable battery packs I can load/unload on a single VAN.
[B]If we take as example the lithium-ion battery of the Smart Electric Drive (16,7 kWh capacity) how much would weight a portable battery pack capable of recharging it? Which size could it have? How many time should it be connected to completely charge the Smart Electric Drive battery[/B]?

Please feel free to write any observation, doubt or proposal,
And most of all… thank you in advance for any help! :smiley:

This is what makes this forum so interesting, the chance to chat about new and innovative ideas which many of us just ignore without looking further into them.

This sounds like a very interesting idea and I would like to see what the experts on the forum think. Is it viable?

Your idea is definitely awesome and really realistic these days. Why not? that is surely okay so why not push through with the idea. I’m ecstatic to know the result.

I think you might be much better off hauling a generator around, rather than another battery pack.

Keep in mind you’ll need more volts in your recharging pack than in the vehicle pack, because electricity is consumed in the charging.

If you expect to need this on an ongoing basis, perhaps you can design your entire pack so it could be swapped out with a duplicate. This might require a portable fork-lift!

I still think the generator would be better. A relatively inexpensive one would fully charge your EV in the same amount of time that plugging it in would take.