Using Tesla car as a Powerwall - Is it possible?

[ReddyLeaf]

The reason why you would not want to use your car as a Powerwall is the impact on cycle life. The car only has battery which lasts less than 1000 cycles. So you really don't want to waste them to power your home if you can get a battery which is designed for this application for a relatively cheap price. Better to go with a Powerwall2 or sonnen unit for you in the UK.

sorry not true. 1000 cycles is ca. 250,000 mi. There are vehicles with nearly this mileage and much less than 20% loss, still plenty of range left. If properly cycled around 30-70% SOC and kept from getting too hot (less than 90F), the battery will likely go 500,000 miles, much farther than most other parts. Heck, there's even a 2011 Leaf with 150,000 mi on it (2000 cycles, with no thermal protection, most susceptible chemistry for thermal degradation). It doesn't make sense for the Leaf, unless a very low mileage driver, but it makes sense for almost all Tesla's, except high mileage drivers.

 

[Schumpeter]

In California I am on a pilot with Ohm Connect and it will tell my car not to charge if the grid is stressed. (They call it an Ohmhour when a peaker plant is running)

Cool sounds like a similar solution. What do you receive in return for your flexibility?

 

[Aussie]

sorry not true. 1000 cycles is ca. 250,000 mi. There are vehicles with nearly this mileage and much less than 20% loss, still plenty of range left. If properly cycled around 30-70% SOC and kept from getting too hot (less than 90F), the battery will likely go 500,000 miles, much farther than most other parts. Heck, there's even a 2011 Leaf with 150,000 mi on it (2000 cycles, with no thermal protection, most susceptible chemistry for thermal degradation). It doesn't make sense for the Leaf, unless a very low mileage driver, but it makes sense for almost all Tesla's, except high mileage drivers.

Indeed, if you
- Keep the temperature below 90F
- and you leave the SOC between 30%-70%
- and you don't use any DC fast charging
- and the pack gets lots of rest time

you will be able to get much more out of it. Also, we actually don't know what the real capacity of the pack is, we only know what it is being sold at. So 20% below the name plate capacity might be 35% below initial capacity which is close to end of life. If you talk to the taxi drivers at AMS airport you hear that most of them are at their 2nd or 3rd pack at 250,000km. In any case, I personally would not use my car battery for my home with the exception to providing power in an emergency.

 

[DFibRL8R]

I personally would not use my car battery for my home with the exception to providing power in an emergency.

Completely agree with this. I have considered purchasing a fossil fuel-burning generator for emergency power backup, but would much rather use a battery back up system such as PowerWall (especially since I have grid-tied solar). It is hard to justify the cost of a PowerWall system for the rare outage in my area. Being able to tap the energy in the car for emergency purposes to run a sump pump, refrigerator etc during an outage would be a very nice feature that would add value to the vehicle platform without compromising the battery much at all. Not to mention use in other scenarios such as camping, remote job site work.

 

[ReddyLeaf]

If you talk to the taxi drivers at AMS airport you hear that most of them are at their 2nd or 3rd pack at 250,000km. In any case, I personally would not use my car battery for my home with the exception to providing power in an emergency.

Hmmm, I had not read that. Perhaps there have been more pack failures than is generally known. Even so, taxi use is definitely different than normal personal use and I would classify that as high use, not applicable to my example.

 

[montreid]

V2H (Vehicle-To-Home) is very different from V2G. Powerwall is essentially V2H that's mounted instead on 4 wheels.

Powerwall battery is the same as the Tesla battery. There maybe electronics software regulating the cycling and charge, but the intent of the Powerwall is to discharge daily and cycle--much higher and deeper cycles than the vehicle, yet there's NO concern on degradation. Heck, Nissan is using old Leaf batteries for their powerwall solution.

This is purely an economic issue and that's what kills me about Tesla on this. They could easily allow their cars to plug into a PV system instead of the powerwall battery. But why sell one battery when you can sell two? Tesla will NOT be the one to push this when they have to feed the Gigafactory and build larger Solar Powerwall systems.

I'm waiting for someone to hack; or Honda bridge their 9000 Generator technology over once they get off their Fuel Cell duff.

This is where LG/GM can really upset the apple cart since they have no Powerwall solution and can leverage the Bolt to do this.....

In the meantime, I'm shaking my head with 30+ KwH sitting on my driveway nightly just sitting there, where it could readily plug into my array and feed the house in the evenings.

 

[Ampster]

Powerwall battery is the same as the Tesla battery. There maybe electronics software regulating the cycling and charge, but the intent of the Powerwall is to discharge daily and cycle--much higher and deeper cycles than the vehicle

I thought the chemistry was different and the Powerwall cycling was not very deep. In typical usage it would be discharging at a slower rate than a car. It is possible I am thinking of PW1

 

[montreid]

This is a simplistic powerwall look -- the takeaway in this discussion - powerwall FULLY discharges.

-With EV and V2H in mind, the scenario would look a bit different where during the day netmetering+PV will support the grid, the V2H-EV will support the home in the evening, and the grid will recharge the EV overnight where demand remains the lowest, outpacing the traditional generation.