mux
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Leaf Number: 6177

Re: I made a transparent CAN bus bridge with logging, requesting input

Wed Jul 04, 2018 10:30 pm

For that you'd need the 4-CAN board (or, well, at least 3 CAN buses). One needs to talk transparently with the VCM and the other would need to be read and its capacity added to the other. It's a bit involved but could certainly be done. I'll see if I can put this kind of functionality in the release firmware.

alozzy
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Re: I made a transparent CAN bus bridge with logging, requesting input

Thu Jul 05, 2018 5:45 pm

@mux Could you mod your transparent CAN bus bridge to intercept the CAN bus signals for battery charging, with the intent to spoof the stock BMS into thinking that the car is fully charged, when in fact it's at 80% SOC?

There seem to be so many post 2013 owners who want the 80% charging feature, so if you could create a reasonably priced device that would do that one thing, I'm sure you would have no shortage of customers.
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

mux
Posts: 170
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: I made a transparent CAN bus bridge with logging, requesting input

Fri Jul 06, 2018 11:14 pm

Ooooooh... I understand this now. They REMOVED the 80% feature? That's stupid. I had somebody else contact me about this and I didn't understand what he meant.

Yeah, that's pretty easy to do. I'll put it on my features list.

alozzy
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Re: I made a transparent CAN bus bridge with logging, requesting input

Sun Jul 08, 2018 6:24 pm

Yeah, they really only had it on the 2013 model year. I'm guessing there are lots of owners who would pay up to $150 US, just to get this feature alone...
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

RkEvHopeful
Gold Member
Posts: 19
Joined: Tue Apr 12, 2011 7:40 am
Delivery Date: 07 Jul 2011
Leaf Number: 6154

Re: I made a transparent CAN bus bridge with logging, requesting input

Mon Sep 10, 2018 11:50 am

carrott wrote:I made something very similar using two USB can bus interfaces and a python script to bridge them together. It decodes a lot of the data from the Nissan Leaf battery and allows you to modify frames on the fly. This sort of tools is very useful for reverse engineering! See https://carrott.org/blog/archives/159-Nissan-Leaf-CAN-Bus-Man-In-The-Middle.html for details and source code.


My 2011 Leaf onboard charger (OBC) died last month. I am looking for an open source replacement for the OBC but one of the sticking points is getting it to work with the Leaf. Did you get enough info with your testing (https://carrott.org/blog/archives/159-N ... iddle.html) to determine if an aftermarket or open source charger could be used?

Thanks,
RK

mux
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Re: I made a transparent CAN bus bridge with logging, requesting input

Tue Sep 11, 2018 2:12 am

Technically, if you really need an OBC quickly and don't have the time or willingness to properly implement offline charging (i.e. charging when the car is otherwise in a non-ready state), you can use a raw mains to 392V CCCV charger connected to the OBC battery connections and put the car into ready mode to close the main contactors and energize that circuit. Note that the 2011-2012 generation has a pretty wimpy cable gauge, so don't try to charge faster than 6kW.

RkEvHopeful
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Re: I made a transparent CAN bus bridge with logging, requesting input

Tue Sep 11, 2018 9:09 am

mux wrote:Technically, if you really need an OBC quickly and don't have the time or willingness to properly implement offline charging (i.e. charging when the car is otherwise in a non-ready state), you can use a raw mains to 392V CCCV charger connected to the OBC battery connections and put the car into ready mode to close the main contactors and energize that circuit. Note that the 2011-2012 generation has a pretty wimpy cable gauge, so don't try to charge faster than 6kW.


That is an interesting way to get it done and it is a reasonable backup plan. I have the ability to swap the OBC safely if I bought a spare, but they are still very expensive from Nissan, especially for a 2011 car. Would a replacement OBC work out of the box? I've read that changing the BCM requires registration, do you know if changing the OBC with a junkyard spare requires something similar?

Have you logged the OBC can bus enough to enable a non-OEM charger to be used?

mux
Posts: 170
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Leaf Number: 6177

Re: I made a transparent CAN bus bridge with logging, requesting input

Tue Sep 11, 2018 11:34 am

I've done extensive logging on the car, but not on the OBC yet (in order to know for sure, I use the CAN bus bridge I designed and expained earlier in this thread right outside the bus connection of the component I'm interested in). However, I *highly* doubt there is any VIN locking or anything like that going on. I have two clues:
- On the EV-CAN bus, I don't see any messages with challenge/response routines or anything like that while charging
- People have replaced 3kW chargers with 6kW, dealers have even done that, and it seems to just work immediately

So I expect the OBC to be reasonably easily swappable. The main annoyance is having to refill the coolant loop.

In order to use a non-OEM OBC, you will have to spoof the original OBC. The OBC has to issue a wakeup message on CAN and do some chatting to the VCM to let it enable the relays. I don't know exactly what it says, but it will no doubt be synthesizable with my hardware. If you are seriously interested and willing to share your findings, I can send you a CAN bridge to play with.

jake14mw
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Re: I made a transparent CAN bus bridge with logging, requesting input

Tue Sep 11, 2018 12:49 pm

For those of us Leaf owners that don't understand a word of any of this, should this be of interest to us?

User avatar
Marktm
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Re: I made a transparent CAN bus bridge with logging, requesting input

Tue Sep 11, 2018 1:57 pm

Understanding charging (and discharging) protocols for various energy sources (including both chargers and charge controllers) could be the most important "discoveries" that allow (the eventual) massive amounts of EV battery energy storage to stabilize the use of renewables (notably solar). Mux - keep up the great work - CHAdeMO, CCS, Tesla all needed.

Just my opinion.
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.

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