Why can't Teslas charge other Teslas?

Why can't Teslas charge other Teslas?

I thought of this on the way home from work: Wouldn't it be great if Tesla owners could "jump charge" other stranded or low-charge Teslas with a special jump charge cable? I would gladly buy such a charge cable to have in case I run low, and to help out fellow Tesla owners. This capability would alleviate potential buyer's fear of being stranded with no charge, increasing Tesla sales, and promoting the goal of sustainable transportation.

DTsea | 28 april 2017

Its pretty hard to strand yourself.

J.T. | 28 april 2017

Do you carry gas cans around in your ICE vehicles just in case?

mntlvr23 | 28 april 2017

Now if Teslas could mate and have offspring, that would be cool.

reed_lewis | 28 april 2017

The loss when transferring power would be too great. Plus when was the last time an EV owner ran out of power?

This is a solution in search of a problem.

The amount of hardware necessary to allow charging of another device would increase weight, and price for very little usage in the real world.

With the increase in the number of Superchargers which could charge much more quickly than car to car transfer could occur reduces further the need of this solution. Plus there are chargers which are J-1772 pretty much everywhere. Do you really want to have to stop for 20 to 30 minutes because some idiot forgot to charge his car?

malbrough | 28 april 2017

All cars can run out of juice. I ran out of gas once in the past 30 years. Walked 1/4 mile to a gas station, bought a gas can and gallon of gas, and then back to the car. Less than $20 later, I was back in business. Try that in a Tesla. The point is, a bunch of folks might buy a Tesla if they feel they won't get stranded. Talking to friends and family, this is their number one concern about EVs.

Getting towed costs $250 and hours of time. A $60 jumper cable and an app could fix that problem and sell cars. And charging ain't rocket science. It's just moving elections back and forth. We're just talking about giving a few percent to a someone in need. Not every place has the charger availability of California. Thanks for the comments!

J.T. | 28 april 2017

Every place with an electric socket is a charging station. Sure, it might be slow at 3-4 miles for every hour of charge at 110v but that's the price you pay for not having a plan.

By the way, did you ever run out of gas again, or did you learn your lesson?

RedShift | 28 april 2017

I hear AAA has charging enabled trucks for road side service.

Just subscribe to the service if you are worried about running out of charge.

reed_lewis | 29 april 2017

The tesla car will alert you and pretty much demand to be charged when it is low. I once tried going to zero percent of charge and the car displays some messages that says you have to charge now.

To run out of power in a tesla is something that you have to want to do.

RedShift | 29 april 2017


Yes, but what if I WANT to run out of charge, and will only take charge from another Tesla which is nearby? May be I just want to meet Tesla owners in various parts of the backwoods!

janendan | 29 april 2017

How about Tesla to Home? With 75kwh of energy in the car, wouldn't it offer better solution than five power wall size batteries to cover your home? Especially in the event power is lost after a major 'cane. In south Florida we can lose power from the grid for as much as a week. No A/C with 90f and 90% humidity. You fill your tubs, pots & pans before the storm. Just aside from the tesla to tesla discussion.

carlgo2 | 29 april 2017

George Carlin once said the stupidest thing in the world was running out of gas because there was a gauge to tell you that was coming up.

Of course in the ICE world there are fuel stations everywhere, so not getting some is an indication of stupidity or bad decisions.

With viable chargers few and far apart, and with the screen not necessarily providing reliable information, it is more understandable to run out of battery.

With zillions of EVs on the road at some point, hopefully capable of fast charging, AAA charge trucks would make sense as there would be a goodly number of calls.

mntlvr23 | 29 april 2017

AAA has had this for over 6 years.
Not sure how widespread, or what you would expect for a wait.

J.T. | 29 april 2017

>>>>>, and with the screen not necessarily providing reliable information, it is more understandable to run out of battery.

This is a ridiculous statement. There's more than enough information: how much charge, how far can you go, nav will tell you how far it is, stick a finger out the window to check the wind and you have all the information you need not to run out of juice. | 29 april 2017

To add to JT, the car will show you how much power you'll have left on a navigation route and even for a round trip. Big warnings if you are going to exceed the range before you even start out.

I expect getting a flat tire happens 1000 times more often than running out of power.

Frank99 | 29 april 2017

Electrically, it would be a very difficult think.

You could do it by building a high-power DC-to-AC inverter into the car so you could connect the dead car via a UMC and charge at 40A. But that inverter would be expensive, and not used in 99% of cars.

You could do it by connecting the two batteries directly together - but you couldn't control the rate of charge. If one of them was a fully charged 400V battery, and the other a depleted 360V battery, nothing good could come of the result.

You could do it by putting in the equivalent of a supercharger into the charged car - it could communicate with the dead car, determine the voltage and current that the dead car could accept, then do a DC-to-DC conversion to charge it while monitoring the dead car to make sure it doesn't overcharge. Once again, an expensive solution.

It's just not a feasible thing to do.

reed_lewis | 29 april 2017

Tesla will never allow the car to distribute power to other destinations. There are a couple of reasons why:
1. If power is allowed to the pulled from the car, and it causes issues with the car, what happens?
2. Imagine if someone went to a supercharger every day, and then turned around and went home and used the power to power their house. Tesla would be powering a house. Never going to happen.
3. The hardware required to accomplish this is not trivial, so it would add cost, and weight.

janendan | 29 april 2017

As a retiree my solar panels wouldn't need a powerwall. Just an inverter to plug the car into after dark or when grid fails. When the 'cane's come.

RedShift | 29 april 2017


What he said in 3).

Cost and effort aren't worth the 1-2 cases a year worldwide of this happening. OP is smoking crack if he thinks this is easy, or costs very little.