How can I use Hyundai EV batteries for stationary use?

[lagmonger]

I have access to several 77.4 kWh Hyundai Ioniq 5 batteries that I would really like to use at my house for stationary storage, but I have no idea how to make that work. Does anyone know what it would take to hook these up to charge off solar and power my house?
I believe they operate at 697 V, which I'm guessing is too high for a lot of normal hardware. I'd like to keep the pack intact if possible, but am open to other options.
I also know there's a lot of thermal management in the vehicle to keep these batteries happy and healthy, but I'm hoping passive cooling will be ok for stationary use, which should be much less severe (the high performance version of this vehicle can pull 448 kW!).

Any insight would be greatly appreciated.

Here's what the inside of the pack looks like (from YouTube):

 

[rodrick]

697 volts is a definite kill you voltage you make a mistake and it’s game over so if your not familiar with working with that type of voltage and have the proper ppe I recommend you don’t mess with them also depending on the battery chemistry you may not want them around anything you value not all lithium batteries are safe to put in a dwelling some can experience a thermal run away catch fire and you can’t put them out I highly recommend you do a lot of research on them before attempting to work on or use them plus your going to have to get the voltage down to 48 to 56 volts to use most of the inverters available

 

[jpwhit]

I've done what you want to do with Tesla Packs, and it wouldn't take a lot for me to figure out how to do the same thing with that pack. But I couldn't do it without having a pack to work with. I do like the look of how that pack is constructed. Looks to have fairly good modularity and as such would be pretty easy to work with.

That's an 800V pack when fully charged. So, to use that battery voltage directly, you'd have to use a commercial HV battery inverter. They are typically setup to work with battery packs up to 1000v. Or the approach I'd probably take is to reconfigure the bus bars on that pack to split it into two 400V sections, and then put those 400V sections in parallel to convert it into a 400V pack with twice the AH rating. Then it would work with pretty much all the HV DC inverters such as the Goodwe GS9600A-ES that I typically use or the new SMA Sunny Boy Smart Energy. I haven't used one before, but the Solis S6 Hybrid inverter is another viable option as well. And there are others on the market.

The hardest part will be to reverse engineer the built in BMS system and build an appropriate gateway box to do protocol translation between the battery BMS system and one of the inverters BMS communications interface. And I recommend doing that to have the full safety of the BMS system. But it's also possible to build a "BMS" comms box that does more minimal monitoring of the battery and gives the inverter the data that's required for it to operate. The latter is lot easier because it can be done w/o having to reverse engineer the built in BMS system.

 

[ksmithaz1]

I would think you could parlay enough cash in the auto-aftermarket to buy similar rack mount LifePO4's ready to go with a standard inverter.

 

[lagmonger]

697 volts is a definite kill you voltage you make a mistake and it’s game over so if your not familiar with working with that type of voltage and have the proper ppe I recommend you don’t mess with them also depending on the battery chemistry you may not want them around anything you value not all lithium batteries are safe to put in a dwelling some can experience a thermal run away catch fire and you can’t put them out I highly recommend you do a lot of research on them before attempting to work on or use them plus your going to have to get the voltage down to 48 to 56 volts to use most of the inverters available

I fully recognize the potential danger of high voltage and would take extreme caution if I do anything.

 

[lagmonger]

I would think you could parlay enough cash in the auto-aftermarket to buy similar rack mount LifePO4's ready to go with a standard inverter.

That would be a simple solution, but selling them is not an option (basically for liability reasons). I could take them for personal use or they will get scrapped.

 

[lagmonger]

I've done what you want to do with Tesla Packs, and it wouldn't take a lot for me to figure out how to do the same thing with that pack. But I couldn't do it without having a pack to work with. I do like the look of how that pack is constructed. Looks to have fairly good modularity and as such would be pretty easy to work with.

That's an 800V pack when fully charged. So, to use that battery voltage directly, you'd have to use a commercial HV battery inverter. They are typically setup to work with battery packs up to 1000v. Or the approach I'd probably take is to reconfigure the bus bars on that pack to split it into two 400V sections, and then put those 400V sections in parallel to convert it into a 400V pack with twice the AH rating. Then it would work with pretty much all the HV DC inverters such as the Goodwe GS9600A-ES that I typically use or the new SMA Sunny Boy Smart Energy. I haven't used one before, but the Solis S6 Hybrid inverter is another viable option as well. And there are others on the market.

The hardest part will be to reverse engineer the built in BMS system and build an appropriate gateway box to do protocol translation between the battery BMS system and one of the inverters BMS communications interface. And I recommend doing that to have the full safety of the BMS system. But it's also possible to build a "BMS" comms box that does more minimal monitoring of the battery and gives the inverter the data that's required for it to operate. The latter is lot easier because it can be done w/o having to reverse engineer the built in BMS system.

That sounds promising.
I may be able to get the Kona EV battery instead, which is "400 V" (358 V). Seems like that would be easier since it wouldn't have to be reconfigured.
I figured the BMS and communication would be the biggest challenge. How long do you think it would take to reverse engineer?

 

[jpwhit]

I would think you could parlay enough cash in the auto-aftermarket to buy similar rack mount LifePO4's ready to go with a standard inverter.

Even if he were allowed to sell it, there just isn't much of a market for used EV batteries. There just aren't many EV battery failures, and the battery warranties are typically quite long, so for the Hyundai, I doubt there are any vehicles out of warranty. That's the main reason that used EV batteries are such a good deal for solar use. There are way more out there and not much of a market looking to buy them. Net, dirt cheap prices.

 

[jjww]

I would Love to find these "dirt cheap prices" on used ev batteries, have any leads???

 

[jpwhit]

Make offers on eBay. People have them on ebay but they just sit for months or years and don't sell. I've picked up packs on ebay with offers of 1/4 of the asking price. Also, It's much easier to get people to take low offers on ebay if you've have or rent a trailer and come pick the packs up. It's a lot of work for the seller to ship them freight. And it's a lot of extra cost in shipping as well.

Also if you're going to disassembly the pack anyway and use the modules, look for a pack with physical damage and potentially one or more damaged modules. People always sell those for cheap.

I'm on the east coast, so this is my experience with packs for sale on the east coast. Situation may be different on the west coast.

 

[jpwhit]

Here's an example. 3 out of 4 good modules. So 60kwh of capacity for $900 in the end. Way better quality batteries than people typically buy here to assemble their own packs. And no assembly required. And the biggest cause of fires and other safety issues is more often poor connections between cell, fuses, and such than problems with the actual battery cells.

 

[offgridandy]

I have access to several 77.4 kWh Hyundai Ioniq 5 batteries that I would really like to use at my house for stationary storage, but I have no idea how to make that work. Does anyone know what it would take to hook these up to charge off solar and power my house?
I believe they operate at 697 V, which I'm guessing is too high for a lot of normal hardware. I'd like to keep the pack intact if possible, but am open to other options.
I also know there's a lot of thermal management in the vehicle to keep these batteries happy and healthy, but I'm hoping passive cooling will be ok for stationary use, which should be much less severe (the high performance version of this vehicle can pull 448 kW!).

Any insight would be greatly appreciated.

Here's what the inside of the pack looks like (from YouTube):
View attachment 223703

I don't know if this helps but I am in the process of carrying out a similar conversion on a near new 50kWh EV pack. https://diysolarforum.com/threads/re-purpose-peugeot-e-208-battery.80269/#post-1127884

I have rebuilt the 18 modules, as a 48V set up, down from 400V, keeping the "on board" daughter circuit boards to "do" the cell management. In stead of hacking the BMS I have obtained one purpose built for these modules. I found a firm that supplys the DIY EV car market. They have a BMS that suites my set up and may be able to do other set up. Here's a link https://wdrautomatisering.nl/ may be this will help.

 

[jpwhit]

That sounds promising.
I may be able to get the Kona EV battery instead, which is "400 V" (358 V). Seems like that would be easier since it wouldn't have to be reconfigured.
I figured the BMS and communication would be the biggest challenge. How long do you think it would take to reverse engineer?

Nearly impossible to say how long it can take to reverse engineer something like this. Depends for example if part numbers of chips on the boards are readable and are off-the-shelf parts as opposed to custom parts. It's also generally helpful to have a car that's compatible with the pack so you can use sniffers to watch the back-and-forth traffic between the pack and the car's electronics. Many of these EV BMS communication connections are also fully airgap isolated for safety reasons, and that can really add to the challenge.

 

[lagmonger]

I don't know if this helps but I am in the process of carrying out a similar conversion on a near new 50kWh EV pack. https://diysolarforum.com/threads/re-purpose-peugeot-e-208-battery.80269/#post-1127884

I have rebuilt the 18 modules, as a 48V set up, down from 400V, keeping the "on board" daughter circuit boards to "do" the cell management. In stead of hacking the BMS I have obtained one purpose built for these modules. I found a firm that supplys the DIY EV car market. They have a BMS that suites my set up and may be able to do other set up. Here's a link https://wdrautomatisering.nl/ may be this will help.

Thanks for the info.
Pulling out the modules may be the simplest solution.

 

[lagmonger]

Nearly impossible to say how long it can take to reverse engineer something like this. Depends for example if part numbers of chips on the boards are readable and are off-the-shelf parts as opposed to custom parts. It's also generally helpful to have a car that's compatible with the pack so you can use sniffers to watch the back-and-forth traffic between the pack and the car's electronics. Many of these EV BMS communication connections are also fully airgap isolated for safety reasons, and that can really add to the challenge.

Understood. Thanks for the response.

 

[ThaiTaffy]

I've noticed BYD modules coming up for sale here recently around 25v per pack but the busbars BMS wires are pretty much exposed so converting to 48v and adding your own BMS seems trivial the only issue here is price, people in Thailand don't seem to understand pricing on the second hand market be it solar panels or batteries they just work out per w price of a brand new unit and price per w the same for 2nd hand. Though maybe as ev's become more and more popular here using cells from them maybe come more viable. Thailand do love a traffic accident so as long as it's not ball of flames I would think the packs may flood the market.