Using a Model 3 battery bank as a domestic powerwall

[ElpacRovi]

Hi all, my first post. I'm interested in researching using the Model 3 battery pack as a powerwall for home storage/supply of solar power. The Model 3 battery pack varied from the Models S and X batteries in that their battery packs could easily be broken down into 24v modules and so 2 in series would give the 48v that is standard within the solar industry. The Model 3 battery pack is only divided into 4 modules each with 96v.

I can easily get a 48v - 96v DC booster to charge the modules and a 96v - 48v transformer to bring it back down to the industry standard ... my stalling point is finding a BMS to balance the individual cells in the modules and balance the modules. The pack comes with individual BMS's contained within each module and what appears to be a 'master' BMS to balance the modules but can they be activated without the rest of the car!?

If anyone has any knowledge or experience of such a venture I would love to hear from you or maybe you know someone who has already performed the task or tried to and failed ... I would still like to hear to find out what failed and maybe why.

BTW, has a test in a Model 3 last year but the Y was awaited and I thought the Y would be more to my needs as a county boy.

 

[UkNorthampton]

Just some links as a start, not something I'd do, but I loved Jack's videos (RIP) - assuming you have a few hours (days... might want to up the playback speed)

https://www.youtube.com/user/marionrickard/search?query=model%203

https://www.youtube.com/user/marionrickard/search?query=bms

Old (2017, Model S), they've done a lot of work since on Model 3 -

- reading of values -

Items to buy? (might be best to give them a phone call/email for your specific questions/needs) - they'll probably point you to further resources, or do a reverse search to one of these links

EVTV Motor Verks | Store

EVTV Motor Verks Store

store.evtv.me

Tesla Model 3 Vertical Rack "Fishbone"

Thinking about replacing your battery pack in your solar system build or building a new one nothing says quality battery like Tesla, impress your friends and neighbors with this innovative vertical storage rack from the battery building experts at EVTV, comes with wheels to move into place along...

store.evtv.me

OFF-Grid Must Haves

EVTV Motor Verks Store

store.evtv.me

from ahref.com (backlinks to EVtv.com)

 

[ElpacRovi]

Hi Northampton, sorry I didn't thank you for your input ... it seems I maybe didn't click the Post button!

Anyway, yes, thanks for the links. I know the vids by the guy in your links (now deceased, RIP). They are very long winded and don't really give much detail ... they are more an overview. I'm now wanting to try and buy the lead from the car charging socket to the Penthouse input but it seems very model specific. If I use eBay's compatibility function it asks me which I have of about 6 version options for the Model 3! I'm guessing the difference is the length of the lead and how it is routed through the car so am trying to research that. My thinking is if I can get that lead and a Tesla (external) charging lead then I can charge the battery pack and maybe all the BMS etc. electronics will operate (I'm told the circuits in the Penthouse are self contained to it). That just leaves how to draw the power out ... that should be relatively easy. I have ID'd the main battery terminals so can draw off a 200vDC or 400vDC supply (maybe even 96vDC from each of the modules), step it down to 48vDC to feed into a standard domestic controller/inverter.

 

[UkNorthampton]

Hi Northampton, sorry I didn't thank you for your input ... it seems I maybe didn't click the Post button!

Anyway, yes, thanks for the links. I know the vids by the guy in your links (now deceased, RIP). They are very long winded and don't really give much detail ... they are more an overview. I'm now wanting to try and buy the lead from the car charging socket to the Penthouse input but it seems very model specific. If I use eBay's compatibility function it asks me which I have of about 6 version options for the Model 3! I'm guessing the difference is the length of the lead and how it is routed through the car so am trying to research that. My thinking is if I can get that lead and a Tesla (external) charging lead then I can charge the battery pack and maybe all the BMS etc. electronics will operate (I'm told the circuits in the Penthouse are self contained to it). That just leaves how to draw the power out ... that should be relatively easy. I have ID'd the main battery terminals so can draw off a 200vDC or 400vDC supply (maybe even 96vDC from each of the modules), step it down to 48vDC to feed into a standard domestic controller/inverter.

No worries. Best of luck, be safe. As I said, I wouldn't (couldn't!) do it.

Hopefully some of the backlinks to EVTV might be worth searching or posting, especially the forums

 

[btc1k]

I'd love to do this, and have also seen the battery banks available cheaply second hand... Seriously cheaper than a powerwall

 

[ElpacRovi]

To btc1k and others who may be interested I have had help from SuperfastMatt on youtube in respect of his conversion of an old Jaguar to electric using a Tesla battery pack (mine is a 1104423-00-N battery). It seemed to me to be a fair question to ask ... how do you charge it and what parts did you need from a Model 3 to be able to charge it? I couldn't see that to charge the battery pack bolted to a chassis would be any different than to charge the same battery pack bolted to a wall! Anyway Matt graciously responded advising me that all I needed was the internal charging cable from the charge socket to the penthouse and the little white charge controller box that the lead from the charge socket plugs into. You can see the video that sparked our conversation here. Hope this is of interest to anyone considering using a Model 3 battery out of a car.

 

[btc1k]

Interesting thanks, I guess for us less technically minded, if anyone had an idiots guide to how to do this, and run a BMS, it would be ideal !

 

[DiyEvRepair]

Anyone had success using Tesla 3 modules for DIY powerwall? My main question is - is it possible to use the Tesla BMS, or would a custom BMS need to be wired in?

Thanks!

 

[Andywil]

Anyone had success using Tesla 3 modules for DIY powerwall? My main question is - is it possible to use the Tesla BMS, or would a custom BMS need to be wired in?

Thanks!

I assume you are talking about the battery pack on its own, because no chance of using the car as it does not support reverse "charging".

 

[Adopado]

I assume you are talking about the battery pack on its own, because no chance of using the car as it does not support reverse "charging".

It's explained in the posts. This is using "modules" from battery packs to build your own home storage battery. The only connection with the forum is that they are discussing ex Model 3 batteries.

 

[DiyEvRepair]

Right, will one Tesla 3 module balance itself when disconnected from everything else? I know each module has a BMS module on top, but I am not sure if it will do the balancing when on its own.

Thanks

 

[Richardrsb]

I am currently working on this project. Check out instagram: Richardrsb

 

[Richardrsb]

Right, will one Tesla 3 module balance itself when disconnected from everything else? I know each module has a BMS module on top, but I am not sure if it will do the balancing when on its own.

Thanks

No, it will not. I removed them, and will use the pack with an OrionBMS which is capable of 96S

 

[Richardrsb]

Anyone had success using Tesla 3 modules for DIY powerwall? My main question is - is it possible to use the Tesla BMS, or would a custom BMS need to be wired in?

Thanks!

You will need a custom BMS. (OrionBMS, or Batrium) capable of 96S (400VDC)

 

[Dale Barwick]

Hello; I am doing the same. I have learned that the charging plug needs to be from the same car. The tesla Penthouse must be hacked by a control module to get the contactors to close so the output terminals are energized. VERY DEADLY 400v dc output. I am designing a system to operate on it.