powerwall2 behavior when paired with solar

[solardreamer]

I don't think either of my Teslas have a 250 Amp rated auxiliary power outlet. The DC to DC converter may be rated at 250 Amps but I don't know where I would access that. I suppose I could clamp on to my 12 V battery terminals but it is fairly hard to get to and I have another source of backup power so I don't need to stress my motive power.

The cigarette lighter sockets are only good for 15A. You connect inverter to the 12V battery terminals. Not sure why you find it hard to access battery terminals. I don't remember any special difficulty on my Tesla or other EV's I owned (Chevy Spark EV, Mercedes B250e). I have seen people setup permanent battery cables with Anderson connectors for quick connect/disconnect. The frunk is perfect space for a small inverter. I have natural gas generator so EV would not be a primary backup power source for me either. However, it's a good and easy option to have.

[astroboy]

I don't think either of my Teslas have a 250 Amp rated auxiliary power outlet. The DC to DC converter may be rated at 250 Amps but I don't know where I would access that. I suppose I could clamp on to my 12 V battery terminals but it is fairly hard to get to and I have another source of backup power so I don't need to stress my motive power.

right - the cigarette lighter probably has a 10A fuse or so but you can connect right to the battery. i was just reading this thread at one of the bolt forums:

https://www.chevybolt.org/threads/us...-backup.14986/

looks like the bolt is good for > 100A at the battery terminals (though there is some kind of current sense in series with the battery so i guess you're supposed to ground the inverter on the chassis.)

anyway this would be a stopgap for the PGE power shutoffs just to keep the refrigerator running. i have a gasoline generator but i really don't want to run that for extended periods nor do i have enough gasoline on hand to do that...

[Ampster]

Many people have successfully done this to get through natural disasters just check the EV forums. EV DC-DC converters are typically rated for 120A-150A with some (e.g. Tesla) up to 250A so it's definitely enough for essential backup power needs. The converters usually have a fuse but like any battery inverter system you should put in your own fuse.
...............

I don't think either of my Teslas have a 250 Amp rated auxiliary power outlet. The DC to DC converter may be rated at 250 Amps but I don't know where I would access that. I suppose I could clamp on to my 12 V battery terminals but it is fairly hard to get to and I have another source of backup power so I don't need to stress my motive power.

[solardreamer]

this is true - i know there are/were guys on the old prius yahoogroup that would do this with a gen2 prius. however even at 1200W you'd be calling for 100A on the 12V side... can you really pull that much current from the 12V system on a bolt without blowing a fuse somewhere in the car?

also nissan had demoed whole-home backup with a home inverter plugged into a leaf but i don't know if that went anywhere... it might have just been a prototype.

Many people have successfully done this to get through natural disasters just check the EV forums. EV DC-DC converters are typically rated for 120A-150A with some (e.g. Tesla) up to 250A so it's definitely enough for essential backup power needs. The converters usually have a fuse but like any battery inverter system you should put in your own fuse.

As for Nissan V2G/V2H, I have been waiting for years now since they talked about it 5+ years ago. I remember reading DOE/DARPA have also funded several V2G projects over the last decade but no generally available products. The main issue is that car companies still make much more profit from traditional ICE cars.

Given the relatively slow EV adoption, I think EV companies should make backup power a feature and selling point to help get more EV adoption. Just as the smart phones provided many more functions than just replacing the traditional cell phone function to get large volume adoption. EV's need to do more than just traditional ICE cars and half baked self-driving function is not it.

[scrambler]

this is true - i know there are/were guys on the old prius yahoogroup that would do this with a gen2 prius. however even at 1200W you'd be calling for 100A on the 12V side... can you really pull that much current from the 12V system on a bolt without blowing a fuse somewhere in the car?

I have installed the 1000W inverter kit from the guy below

https://www.evextend.com/

I replaced the protecting fuse by a breaker like the one below, which makes it easier to reset if you pull too much

https://www.amazon.com/gp/product/B00139FQSS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It works great I can power essentials manually

[Ampster]

.........
also nissan had demoed whole-home backup with a home inverter plugged into a leaf but i don't know if that went anywhere... it might have just been a prototype.

I think they have rolled out some in Europe.

[astroboy]

I agree. For basic backup power needs, you can already run inverter off the EV DC-DC converter that would be good for running essential loads like fridge and lights up to ~1500W. Assuming you keep the 60Kwh battery charged it should have no problem meeting occasional basic backup power needs and still allow you to drive around.

this is true - i know there are/were guys on the old prius yahoogroup that would do this with a gen2 prius. however even at 1200W you'd be calling for 100A on the 12V side... can you really pull that much current from the 12V system on a bolt without blowing a fuse somewhere in the car?

also nissan had demoed whole-home backup with a home inverter plugged into a leaf but i don't know if that went anywhere... it might have just been a prototype.

[solardreamer]

yeah unfortunately storage prices are up i guess due to high demand. this is all kind of silly since i already have a 60kwh battery in my car, which would be the perfect home backup.

I agree. For basic backup power needs, you can already run inverter off the EV DC-DC converter that would be good for running essential loads like fridge and lights up to ~1500W. Assuming you keep the 60Kwh battery charged it should have no problem meeting occasional basic backup power needs and still allow you to drive around.

[Ampster]

yeah unfortunately storage prices are up i guess due to high demand. this is all kind of silly since i already have a 60kwh battery in my car, which would be the perfect home backup.

Not if you want to drive somwhere..

[scrambler]

Also looking at the SGIP allocation below

https://www.selfgenca.com/budget_public/program_level_summary/pge

It seems like SGIP for Small Residential Storage (Step 5) is all but gone ($1,760 left...)
That means that no solution will get any subsidy anymore...

I wonder if there are any plans to vote new budgets next year.

[astroboy]

yeah unfortunately storage prices are up i guess due to high demand. this is all kind of silly since i already have a 60kwh battery in my car, which would be the perfect home backup.

[Ampster]

I received quote almost two years ago for step 3 of SGIP. LA Solar's price was $13,000. I let it go and did a DIY with some used Nissan Leaf Batteries I had from a golf cart project and an Outback Skybox.

[astroboy]

@astroboy
By the way what installation date did they give your for your Powerwalls?
Installers seem to still be quite backed up (does not help with prices...)

no idea really - they got back to my initial $100 deposit in one day and asked me to take pictures of the existing panel/wall and give them API access to my PGE account. i did all that stuff right away on friday but have not heard back from them - i planned to call them back today to at least make sure they got all the stuff. i didn't want to give them API access as it requires giving them my username and password (pretty absurd) so i sent them my latest bill which is 1 month shy of true-up.

when the advisor was on the phone with me last thursday, he mumbled something about 1Q 2020.

[scrambler]

@astroboy
By the way what installation date did they give your for your Powerwalls?
Installers seem to still be quite backed up (does not help with prices...)

[scrambler]

Thanks, this means the miscellaneous HW like the subpanel is included either in the 1100 or the 2500.
$2,500 is still expensive for a 2 person day job but nothing we can do about that