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Direct Re-Use of EV packs to home energy storage

4805 Views 15 Replies 13 Participants Last post by  UglyCarFan
I am in the early stages of developing a prototype system to connect an EV battery pack into a combined ESS/PV/Inverter system to power the home. Ultimately I think this could be a business opportunity....but I dont want to get too far ahead of myself.

I have worked for a substantial time reverse engineering the Nissan Leaf's CAN network (my background is automotive/EV R&D) and watched Wolftronix's videos with great interest. I think he made it look a bit too easy! Just 2*12V relays to switch it on....really??!? I have a 2014 Nissan Leaf myself but its my daily driver so haven't had the guts to tear it down ... just yet.

I realize there will be significant work in working with the BMS, and ensuring the pack stays healthy....that's hopefully where my experience comes into play.

Ultimately I want to develop something like the attached image.

So my questions to the hive mind are:
  • Has anyone actually done something like this?
  • What were the significant challenges?
  • Is anyone in the UK and up for discussing it?

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This has already been done commercially: bidirectional charging stations allow the EV to export energy to the grid as desired, and this is the same thing without the rest of the EV. So technically it is certainly feasible.
 

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Does this mean you've reverse engineered the leaf charger CAN protocol?

There's a group on this forum who are trying to decode the whole of the Leaf's CAN bus(es) with a spreadsheet here of what's been achieved so far. Charging is sadly missing and it just happens to be one of the things I'm interested in ;).
 

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Discussion Starter · #4 ·
I have partially reverse engineered the charging protocols, and almost completely reverse engineered the Primary CAN for a lot of the main signals in a previous role for a 2011 Nissan Leaf. There doesn't seem to be many changes in the 2013+ Gen 1 Leaf.

I am just in the process of updating my work (I did it for the 2011 Leaf in 2015) and I'll start updating my findings in that spreadsheet.

As I'll have a side-by-side comparison of the pack with a complete vehicle I am hoping I can reasonably easily reverse engineer the remaining charge control signals. My challenge will be resetting the error flags which will occur. I am hoping I will not need the body control module to do this.

This is the fun stuff!
 

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Cool.

I'd Just like to add to save any confusion - that it's not my spreadsheet.

I've been doing some research on re-using a scrap leaf motor for a conversion. I'm hoping to
a) reuse as much as I can without having to change driver boards
b) create a bridge with some additional logic in it to get inputs from the CAN bus of the converted car to control the motor and return various things for the instrument cluster etc.
 

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I've been wanting to do this at my house as well. I have a grid-tied PV system so I was thinking it would be sweet to charge my EV with my panels, then use that to provide energy at night. I'm still just starting my EV conversion, so I probably wouldn't start on this piece for a while, but it's in my plan.

Jimno69ny - How has your system worked out for you? Are you able to use the same JAE charge port to transfer energy back to your home's critical loads?

I was thinking of creating some additional CAN commands to control the system. Perhaps just using a custom board to sniff the CAN line and respond to these additional commands - this could control a transfer switch as well as the inverter. Of course you would have to send DC over the charge cable so you would also need a transfer switch on the vehicle side. I haven't thought it through that much though so I'm probably missing some details at this point. It's easy to get ahead of myself :eek:
 

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V2G? Model S? 60 to 75kWh is great.

I'm thinking about buying an old model S, enjoy it on the open roads as long as I can and then park it at some distance away from my home to be used as storage.

Nice packaging, packs are safe enough when used in a Tesla, and I just read this research paper (MSEE): recycling is the way to go in a circular economy.

And it's not a good idea to use a lot of freshly mined lithium in the next decade.
Production issues, there's enough of it in the world, but not in production yet.
 

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Hello,

Located in Europe, Netherlands,

In this forum I bumped on work of Tom de Bree, his "SIMPbms"
a board with a Teensy, that'll allow to directly connect to a number of cmu's of different car makers.
It'll work with Victron, and SMA inverters low voltage ~48Vdc

https://www.diyelectriccar.com/forums/showthread.php/fs-tesla-vw-outlander-bms-master-198263.html


Currently trying to hook it up with this new product of SMA:
https://www.sma-america.com/products/battery-inverters/sunny-boy-storage-38-us-50-us-60-us.html

So 6 Tesla modules, or 1 complete Nissan Leaf pack, Mitsubishi Outlander Hybrid, or Mitsubishi i-MiEV + SIMP-bms straight into this SMA Sunnyboy High Voltage inverter/charger.

Re-use of second-life bev packs 300-400Vdc on HV hybrid inverters should be the next step.
But as always finding guinea pigs at low project cost is a bit of a problem,
sniffing can-protocol, and help from the community is appreciated, all code will be published on github

best Carel Hassink
 

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Is someone here who know how to control the batteries as they are in the original battery box

I want to do the same thing but with one or two batteries.
What I need is the can computer that supervises the built-in BMS and keeps the battery in good shape and tell me to stop charge or discharge
 

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I am interested in a similar project. In the rental generator market, we need flexible battery packs that can be delivered based on the need of the site. One client may want 50kW x 150kWh and another client may need the same three packs arranges in a 150kW x 150kWh. A modular system of building blocks is desirable. Think of it as the Spark charge Roadie scaled up 10 times the size of each Roadie module.
 

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I am in the early stages of developing a prototype system to connect an EV battery pack into a combined ESS/PV/Inverter system to power the home. Ultimately I think this could be a business opportunity....but I dont want to get too far ahead of myself.

I have worked for a substantial time reverse engineering the Nissan Leaf's CAN network (my background is automotive/EV R&D) and watched Wolftronix's videos with great interest. I think he made it look a bit too easy! Just 2*12V relays to switch it on....really??!? I have a 2014 Nissan Leaf myself but its my daily driver so haven't had the guts to tear it down ... just yet.

I realize there will be significant work in working with the BMS, and ensuring the pack stays healthy....that's hopefully where my experience comes into play.

Ultimately I want to develop something like the attached image.

So my questions to the hive mind are:
  • Has anyone actually done something like this?
  • What were the significant challenges?
  • Is anyone in the UK and up for discussing it?
Any update on the progress? I just bought a e-NV200 to electrify my tractor and at the same time I plan to use its battery for V2H.
It used to have a Chademo port which is able to delivery power both ways, to my suprise my Italian model has only a type 1 charging connector.
I´m not willing to take the battery apart to use its battery cells only. If necessary I keep the car running and develop a safe solution to extract the energy towards my house.

I assume many people out there are working on the same thing, lets group our knowledge and make it happen!

I´m an el. engineer with many years of experience and a lot of tools in reach. If you know existing communities, I´d be happy if you point me the direction ...

Best regards,
Manuel
 

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Sorry, I hit the enter key before I was done. If you really want to make a contribution, figure out a way to do this that would allow the batteries to be utilized LEGALLY in places where the new code demands UL Listed devices. I was super interested in this about 3 years ago, spent a thousand or more hours looking into it, only to be stymied by the recent adoption of the 2020 code by our local AHJ. The inspectors don't really understand it (their own statements) and their approach is "no exceptions...everything must be LISTED". You have to provide them with all the links that prove the products are Listed. Any deviations from that are automatically denied.

I've stopped posting on some of the other forums, because many, many people just want to argue about this topic. Especially those who happen to want to buy a cheap Chinese inverter. I own Victron, and I cannot permit it here. I took my case all the way to the top of the responsibility heap, and was told the same thing...no exceptions. Very frustrating. So I bought SolarEdge. Before anyone flames me for my comments, I'm not pushing any particular brand, not saying that you cannot get a Chinese inverter approved where-ever you live, not saying you cannot just do it, and hook it up. That has always been the case. You can do just about anything you like with your own property, with no permits. You just have to be willing to pay the price if they decide to pounce on you, and make an example of you. Or, your insurance company doesn't pay on a home claim because the equipment wasn't UL approved.

I'd like to see an approach to use these batteries, much as you stated in your post. In the past, when I've described this to someone else, invariably the idea of making a mobile, or detached system that is not permanent is suggested. In our case here, even that has been axed.

I'm waiting for Nuvation Energy to get some of their products back in stock. They have been out of stock for at least 7 months. By the time they are available, it is possible that the prices on ready built rack mount batteries will be cheaper. Now, we just need to make sure they are actually UL LISTED and I'll be good to go.
 
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