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Discussion Starter #1
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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