Tesla Powerwall 2 as battery for offgrid system?

[sio510]

Hi,

I'm new to this offgrid building and trying to figure out if I could buy the Powerwall 2 used (I have a friend who have two powerwall but selling one of the two) and build a DIY off-grid solar array inverter setup. The main focus is to use the powerwall 2 as the battery system only. Solar panel to Inverter (eg4 6000xp off-grid) and connect the inverter
Goal is to charge my tesla with solar.

I don't have any tesla gateway, site controller, or any other tesla related things as only buying the powerwall 2 from the owner.

To summerize, can you use Powerwall 2 like if you would use a 48v Lifepo4 battery on a off-grid solar array inverter setup?

Also just to add, I live in Hawaii so buying a new 48v lifepo4 isn't an easy option due to shipping restrictions and hefty shipping fee.
So finding a used battery is an alternative option for me so please hold off on any advice saying just buy a new 48v Lifepo4 battery.

I just want to know if anyone knows if you can use Powerwall 2 as a battery without gateway (friend needs the gateway for his house, only selling the powerwall)

Thank you in advance for your time and answer.

 

[Vines]

Hi,

I'm new to this offgrid building and trying to figure out if I could buy the Powerwall 2 used (I have a friend who have two powerwall but selling one of the two) and build a DIY off-grid solar array inverter setup. The main focus is to use the powerwall 2 as the battery system only. Solar panel to Inverter (eg4 6000xp off-grid) and connect the inverter
Goal is to charge my tesla with solar.

I don't have any tesla gateway, site controller, or any other tesla related things as only buying the powerwall 2 from the owner.

To summerize, can you use Powerwall 2 like if you would use a 48v Lifepo4 battery on a off-grid solar array inverter setup?

Also just to add, I live in Hawaii so buying a new 48v lifepo4 isn't an easy option due to shipping restrictions and hefty shipping fee.
So finding a used battery is an alternative option for me so please hold off on any advice saying just buy a new 48v Lifepo4 battery.

I just want to know if anyone knows if you can use Powerwall 2 as a battery without gateway (friend needs the gateway for his house, only selling the powerwall)

Thank you in advance for your time and answer.

From what I have heard, there is no more support for off grid systems from Tesla, even if you had the gateway that is needed for it.

The powerwall 2 will not easily play nice with another inverter as it is actively checking if it is connected to the gateway at all times. If the communication or voltage signal is lost the Powerwall goes into safe mode.

My understanding is that the PW2 has a 48 VDC bus, so I think your only chance is to either hack the CAN system to fool it into thinking the PW is connected to a gateway or to hack the PW2 so that you remove the factory inverter and install another inverter connected directly to the DC bus. Neither is a particularly DIY project IMO, unless you are well armed with these skills.

If you were really lucky you would find an off grid firmware and load that into a gateway.

 

[jjrandorin]

To summerize, can you use Powerwall 2 like if you would use a 48v Lifepo4 battery on a off-grid solar array inverter setup?

I would suggest that the short answer to this question is, "No, dont plan on using a Tesla powerwall like this, especially without the rest of the Tesla specific hardware".

 

[Vines]

I would suggest that the short answer to this question is, "No, dont plan on using a Tesla powerwall like this, especially without the rest of the Tesla specific hardware".

I like your answer better.

 

[sio510]

From what I have heard, there is no more support for off grid systems from Tesla, even if you had the gateway that is needed for it.

The powerwall 2 will not easily play nice with another inverter as it is actively checking if it is connected to the gateway at all times. If the communication or voltage signal is lost the Powerwall goes into safe mode.

My understanding is that the PW2 has a 48 VDC bus, so I think your only chance is to either hack the CAN system to fool it into thinking the PW is connected to a gateway or to hack the PW2 so that you remove the factory inverter and install another inverter connected directly to the DC bus. Neither is a particularly DIY project IMO, unless you are well armed with these skills.

If you were really lucky you would find an off grid firmware and load that into a gateway.

Thank you so much for the detailed answer. I am not that technical about hacking the CAN system so I think this is out of my league. I'll find better and easier solution. But your answer helped me greatly to come to this conclusion so thank you very much!

 

[sio510]

I would suggest that the short answer to this question is, "No, dont plan on using a Tesla powerwall like this, especially without the rest of the Tesla specific hardware".

Thank you! I'll try something better than this method. Greatly appreciate your help.