Using Tesla model 3 or Y batteries for solar backup

[evrepair]

Has any of you used a Tesla model 3 or Y battery for solar backup? Either individual modules (~100V) or whole pack (~400V).

I have a battery pack already, and I have solar on the roof with Enphase IQ-8 microinverters.

I'm thinking of using this inverter:
https://www.sigineer.com/product/96...ine-for-tesla-model-3-lithium-battery-module/

And using 2 inner 25s modules in parallel (Voltage range ~92-105V according to my calculations).
Here is the manual for the above inveter:

https://www.sigineer.com/wp-content/uploads/2015/01/Sigineer-Power-High-Power-10000-12000-15000-18000-watt-24V-48V-96V-Inverter-Charger-Manual-614-00504-00.pdf

Wondering if anyone here done something like that? Seems like in addition to the inverter/charger I also need some kind of BMS, any recommendations of what to use?

Thanks!

 

[schmism]

I don't know of any solar charge controllers that support that high of battery voltage.

You can follow the link in my sig for how to DIY AC grid charging for DC. Just string the PSU together to get the output DC voltage you need.

BMS - the only option I know of is to buy the software/hardware people have built to reverse engineer the built in Tesla one. Expensive but AFAIK the only option for tesla packs.

 

[evrepair]

Thank you for the reply! The inverter I linked to above has a built in charger. I don't need solar charge controllers because I am using Enphase microinverters, which output AC.

The Sigineer inverter has a neat feature where it will adjust the AC frequency to turn solar on and off depending on battery state (see attachment).

My main concern is how to do BMS and how to hook everything up together.

I think the plan is to hook up solar (AC output from microinverters, after combiner box) into AC INPUT of the battery inverter, and hook up the AC OUTPUT of the inverter to a breaker in my main panel.

According to the manual, inverter/charger will change the battery from AC on either direction (INPUT or OUTPUT). I will need the BMS to monitor for overcharging and tell inverter to shut off charging if battery is full.

Or am I missing something here?

Thanks!

 

[Mystery Man]

Already being done successfully, just not cheap.

 

[Ampster]

RIP Jack Rickard. I followed his videos when he believed no BMS was necessary when converting vehicles to EVs Before he passed he gave up converting EVs and evolved into high voltage hybrid solar systems.

 

[evrepair]

I didn’t know he passed away but yeah his solutions are too expensive. For my house I don’t need 400V DC; a single 100V 25kwh Tesla 3/Y module should be sufficient for my needs.

 

[Ampster]

I didn’t know he passed away but yeah his solutions are too expensive.

His daughter and some others are trying to keep evtv alive with a few videos. I presume the store is still going.

For my house I don’t need 400V DC; a single 100V 25kwh Tesla 3/Y module should be sufficient for my needs.

I am a big Tesla fan and almost used Model S modules but they were almost as expensive as the LFP cells I used.

 

[schmism]

I am a big Tesla fan and almost used Model S modules but they were almost as expensive as the LFP cells I used.

This seems to be the reoccurring theme. By the time you get a charging solution and BMS to work with the tesla pack, you've spent more than just an standard 48v LFP pack and normal BMS you can get "anywhere"

 

[evrepair]

I already have a Tesla battery pack from a model Y I parted out, so cost wise all I need is either a 96V inverter plus BMS or a 384V inverter and use the Tesla BMS. Plus some wires etc. I was hoping someone done it before but apparently very few people if any are using tesla 3/Y batteries.

 

[niktak11]

I already have a Tesla battery pack from a model Y I parted out, so cost wise all I need is either a 96V inverter plus BMS or a 384V inverter and use the Tesla BMS. Plus some wires etc. I was hoping someone done it before but apparently very few people if any are using tesla 3/Y batteries.

Sigineer has a 96V inverter that they made for Tesla modules

 

[eprotiva]

Yes, i have a 3kw 400v dc inverter, i also have a 10kw mppt for 400v battery. For bms this https://www.evbmw.com/index.php/evbmw-webshop/tesla-boards/tesla-model-3-bms

Text me 417-256-1989

 

[Csecrist12]

I already have a Tesla battery pack from a model Y I parted out, so cost wise all I need is either a 96V inverter plus BMS or a 384V inverter and use the Tesla BMS. Plus some wires etc. I was hoping someone done it before but apparently very few people if any are using tesla 3/Y batteries.

So I am doing exactly what you're doing and being offered assistance by a gentleman in the Netherlands. Extremely knowledgeable guy with creative solutions to this very pack. These packs are extremely energy dense and can handle ALOT of amps. Now our houses don't use the amount a car can pull, but nevertheless, these packs are desirable.

So our solution so far: (Mind you, I'm here in the midwest, North East Indiana)

- Using an Orion BMS to control each full pack (400V) voltage and monitoring. They have systems that can go with a large number of strings and it's a completely robust system in the EV world.
- The Orion BMS would be in communication with your inverter Megarevo R12KH1NA (Including the link here and added the manual below: https://www.megarevopower.com/productinfo4.html) This inverter is a hybrid inverter split phase with a 400V battery input which is crucial. It can also have additional inverters stringed together for larger power if needed. There are a few suppliers I have talked to with pricing around the $2800-$3500 shipping and all for the large 12kw unit. I have heard mixed reviews on these units. I believe they're the same units as the Deye just simply rebranded more or less.


We haven't gone any further into it besides me, testing the packs I have because they were a little damaged, but a deal I simply could not refuse.

But I would suggest ripping off the Tesla BMS as they are riddled with problems for us DIYers and easier to have a system you can control the settings on.

 

[Csecrist12]

I already have a Tesla battery pack from a model Y I parted out, so cost wise all I need is either a 96V inverter plus BMS or a 384V inverter and use the Tesla BMS. Plus some wires etc. I was hoping someone done it before but apparently very few people if any are using tesla 3/Y batteries.

Also, message me and I'd like to get you in a messaging thread with my friend who has been guiding me as he is the one with the knowledge.

 

[RichardRSB]

Has any of you used a Tesla model 3 or Y battery for solar backup? Either individual modules (~100V) or whole pack (~400V).

I have a battery pack already, and I have solar on the roof with Enphase IQ-8 microinverters.

I'm thinking of using this inverter:
https://www.sigineer.com/product/96...ine-for-tesla-model-3-lithium-battery-module/

And using 2 inner 25s modules in parallel (Voltage range ~92-105V according to my calculations).
Here is the manual for the above inveter:

https://www.sigineer.com/wp-content/uploads/2015/01/Sigineer-Power-High-Power-10000-12000-15000-18000-watt-24V-48V-96V-Inverter-Charger-Manual-614-00504-00.pdf

Wondering if anyone here done something like that? Seems like in addition to the inverter/charger I also need some kind of BMS, any recommendations of what to use?

Thanks!

I am currently working on a LR model 3 pack. You need to know a few things:
The entire LR pack has 4 modules total (2 x 25S + 2 x 23S) summed up 46P96S (96 bricks), with a nice capacity of 78kWh.
BMS: for 96S you can use OrionBMS, or Batrium. The Tesla BMS on the modules is useless. (Model S packs can use Tesla, but not model 3 21700 packs)
Charger / inverter: I will use (still awaiting delivery) a Deye 20kW HV. In the USA they are called Sol-Ark. Some models accept the input of the 400VDC from the Tesla pack, and they are available in split phase. They also accept a GEN input from an inverter, or generator.
You CAN parallel modules, but be aware you need to parallel each brick. Basically you convert to 92P25S It can be done to obtain a 100V battery, or even a 48V battery (which is insane, but possible).
In the pack EVERYTHING is aluminium, except the cans of the cells. You need to find a way to solder aluminium.
Questions? Ask. You can follow me on Instagram: Richardrsb to see how things are going here. You will find tons of information.
Greetings from the Netherlands.

 

[evrepair]

I am currently working on a LR model 3 pack. You need to know a few things:
The entire LR pack has 4 modules total (2 x 25S + 2 x 23S) summed up 46P96S (96 bricks), with a nice capacity of 78kWh.
BMS: for 96S you can use OrionBMS, or Batrium. The Tesla BMS on the modules is useless. (Model S packs can use Tesla, but not model 3 21700 packs)
Charger / inverter: I will use (still awaiting delivery) a Deye 20kW HV. In the USA they are called Sol-Ark. Some models accept the input of the 400VDC from the Tesla pack, and they are available in split phase. They also accept a GEN input from an inverter, or generator.
You CAN parallel modules, but be aware you need to parallel each brick. Basically you convert to 92P25S It can be done to obtain a 100V battery, or even a 48V battery (which is insane, but possible).
In the pack EVERYTHING is aluminium, except the cans of the cells. You need to find a way to solder aluminium.
Questions? Ask. You can follow me on Instagram: Richardrsb to see how things are going here. You will find tons of information.
Greetings from the Netherlands.

> Some models accept the input of the 400VDC from the Tesla pack, and they are available in split phase

Which models are those? I couldn’t find any split-phase sol ark inverters that support 490V batteries.

Thanks!

 

[niktak11]

> Some models accept the input of the 400VDC from the Tesla pack, and they are available in split phase

Which models are those? I couldn’t find any split-phase sol ark inverters that support 490V batteries.

Thanks!

They only model that would work well with that battery voltage is the 30k, but that's 3 phase.

 

[builds_love]

Hello, this is a great thread and looking for information to help me with the build I am currently working on. Trying to understand more about frequency shift using Enphase IQ7+ Mirco Invertors with 3KW of solar on the roof of my RV. How do I charge the battery via solar? I can think of several solutions but trying to find the best answer and start.

I purchased SDP-10KW Off Grid Inverter from the EVTV in Missouri, November 2023, picking it up in person. This inverter is connected to a Model 3 Standard Range Plus Battery (54Kw). My batter pack is a Model 3 but the connection on the top of the battery uses a Y rigid cable. I need to modify a Model 3 Cable to bolt to the battery pack safely and securely.

A INGENEXT Battery Controller, which allows me to open and close the Tesla Battery Contactors

The high voltage inverter allows me to easily OPEN and CLOSE and Tesla Battery contactors as it was design under the guidance of Jack / EVTV. Currently I am charging it via a Tesla Mobile Charger using a NEMA 14-50 & NEMA 5–15 which has had some limitations. I have also be able to use Tesla Charging Stations. The issues currently are the battery charge is limited to a certain voltage which I am trying to understand more.

A common issue seems to be the pack will charge to about 333 Volts, reach 335 Volts and stay in this range no matter the amperage flowing into the battery. This was just a temporary solution until I have the solar array built.

If you have information please reach out to me on Instragram @builds_love OR message me via this forum. I would be happy to share any information I have. I think using a Tesla Battery from a savaged vehicle is such a win on so many levels.

 

[Ampster]

Trying to understand more about frequency shift using Enphase IQ7+ Mirco Invertors with 3KW of solar on the roof of my RV. How do I charge the battery via solar?

In order to use Enphase micros you need a source of grid power. In your case to charge batteries you will need a charger which will use available solar from the micros but the charger will use grid power if there is not enough solar generated power from the micros. I am not sure micros are optimal in an RV installation unless you know you can always have a 240 volt hookup.
Frequency shift is an off grid phenomena involving a hybrid inverter providing a grid signal to emulate the grid so the micros will power up. In an RV it is probably more cost effective to use a less expensive off grid inverter that includes a battery charger and charge controller to connect the solar panels on the roof of the RV. That inverter can charge the batteries whether you have a grid connection or not.

 

[builds_love]

In order to use Enphase micros you need a source of grid power. In your case to charge batteries you will need a charger which will use available solar from the micros but the charger will use grid power if there is not enough solar generated power from the micros. I am not sure micros are optimal in an RV installation unless you know you can always have a 240 volt hookup.
Frequency shift is an off grid phenomena involving a hybrid inverter providing a grid signal to emulate the grid so the micros will power up. In an RV it is probably more cost effective to use a less expensive off grid inverter that includes a battery charger and charge controller to connect the solar panels on the roof of the RV. That inverter can charge the batteries whether you have a grid connection or not.

I can emulate the grid using the Sandi Inverter. This will allow the Enphase Micros/Gateway to charge the battery. Working with the charge controller allow the solar power backfeed from AC Output end to DC Input to the battery and we have the Frequency shift function to toggle the inverter's frequency from 60Hz up to 62.5Hz for a half second to allow the grid-tied solar controller to stop the solar production to protect the battery from the overcharging in solar.


While this system is currently in a Custom Box Build "RV" the foot print is very small the Tesla Battery is only 7" high and is under the floor. The end goal is to have a blueprint to help take savage Tesla Battery and package them together in a system to help with Grid Tied properties. Having the Grid would simple be a backup while the primary would be a solar array charging a Tesla M3/Y Battery Pack. High-voltage is the future of battery design and these batteries are the best in the world with the lowest cost per KWH. While initial cost might be higher I believe the end result can be more solid and much cheaper for 54-84KWH battery pack.

Currently these are the numbers I am working with and have spent.
$2,500 - INGENEXT Battery Controller
$5,132 - Standard Range Plus Battery (54Kw) shipped to my door
$500 - Tesla Charge Port controller and cable from battery to Inventer
$4,000 - Sandi SDP-10KW Off Grid Inverter

I feel the total is lower than buying a system of this size off the shelve, simply working out the bugs and understanding more with Canbus messages and frequency shifting between 60hz, 62.5hz and 65hz.