lorenfb
Posts: 1755
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Jun 07, 2018 8:31 pm

mux wrote:In the Leaf, the rapid charger does its own current limiting; all the car does is set a maximum current (120A in the case of Leaf) and a maximum voltage (391V in case of the Leaf). The charger then does constant current-constant voltage (CCCV) charging just like any other battery charger.


The first description/senctence better defines the functionality, since the voltage of the battery increases as it charges. So it's not really a constant
voltage source too during the constant current charging, but limits the max battery voltage as the process completes.
Leaf SL MY 9/13: 65K miles, 50 Ahrs, 5.2 miles/kWh (average), L2 charges to 100% > 1000, max battery temp < 95F, min discharge point > 20 Ahrs

arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Fri Jun 08, 2018 8:51 am

Vehicle asks for specific current and DC charger deploys that. AFAIK 10x per second.
It's not CC CV. Vehicle is not limiting according to pack voltage.
Vehicle is limiting according to maximum cellpair voltage.

Current from DC station varies up and down. Enabling AC for example. Current rises
as peak voltage per cellpair allows more current. And station ramps up.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

mux
Posts: 125
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Tue Jun 19, 2018 6:44 am

Big news!

Alright, holy shit, after a full weekend AND monday of messing up probably everything there is to mess up about this endeavour, I *FINALLY* got my CAN bus bridge to work the way I intended. It now:

- Transparently passes through all CAN messages
- Can selectively edit CAN messages ('man in the middle' attack-type stuff)
- Outputs every single CAN message as well as possible errors out to a serial port

I have mounted this on my EV-CAN right off the VCM and am currently using it to add the extender pack capacity to the main pack capacity by modifying CAN message 0x5bc (available charge signal). This has the desired effect of increasing the amount of kilometers on the dashboard accordingly.

I'm now going to spend the rest of today making some more logging tools and properly writing firmware for the extender pack. I'll post a video maybe tomorrow (depends, I have a busy week ahead).

I don't think I can convey how big this news is. I'm not the first person to spoof CAN this way, but as far as I know, I'm the first person to do realtime CAN bus manipulation in a working Nissan Leaf, certainly for this purpose. This will allow for unprecedented hacking of these vehicles.

I'm revising the board design and layout, hardening it and selling it soon for $40-50, depending on how expensive the potting is going to be.

mmmike
Posts: 11
Joined: Tue Jan 03, 2017 10:29 pm
Delivery Date: 05 Nov 2017
Leaf Number: 407184

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Tue Jun 19, 2018 7:20 am

Yes!

Good work mux
2013 SV 36k 10bars - 48.6 aHr
Charging - Maxx-16 3.8kw exclusively
Central Texas

mux
Posts: 125
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Tue Jun 19, 2018 8:12 am

And a quick follow-up: I just drove about a kilometer with the module in place, but it did stall once. The firmware clearly still needs some polishing before I can reliably get long-term logs. I hope to have this done by thursday, which is when I need the car for a longish trip. Then I should be able to log all CAN messages during a drive to a computer and I"ll post it here.

mux
Posts: 125
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Tue Jun 19, 2018 1:19 pm

And another follow-up: I just finished up the entire thing. I fixed the bug that caused the firmware crash earlier and I got the extender to properly talk to the VCM. The car now correctly displays the remaining range based on the total capacity of all batteries in the car.

It is glorious.

User avatar
Marktm
Gold Member
Posts: 380
Joined: Thu Jan 21, 2016 10:49 am
Delivery Date: 09 Jan 2016
Leaf Number: 022737

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Tue Jun 19, 2018 3:39 pm

mux wrote:Big news!

Alright, holy shit, after a full weekend AND monday of messing up probably everything there is to mess up about this endeavour, I *FINALLY* got my CAN bus bridge to work the way I intended. It now:

- Transparently passes through all CAN messages
- Can selectively edit CAN messages ('man in the middle' attack-type stuff)
- Outputs every single CAN message as well as possible errors out to a serial port

I have mounted this on my EV-CAN right off the VCM and am currently using it to add the extender pack capacity to the main pack capacity by modifying CAN message 0x5bc (available charge signal). This has the desired effect of increasing the amount of kilometers on the dashboard accordingly.

I'm now going to spend the rest of today making some more logging tools and properly writing firmware for the extender pack. I'll post a video maybe tomorrow (depends, I have a busy week ahead).

I don't think I can convey how big this news is. I'm not the first person to spoof CAN this way, but as far as I know, I'm the first person to do realtime CAN bus manipulation in a working Nissan Leaf, certainly for this purpose. This will allow for unprecedented hacking of these vehicles.

I'm revising the board design and layout, hardening it and selling it soon for $40-50, depending on how expensive the potting is going to be.


mux,
Is there a possibility that this programmable "spoofing" of the CAN can be used to hack a pragmatic solution that allows the bi-directional CHAdeMO protocols to be used to design a charge/discharge controller so that my Leaf can be used as the energy storage for my solar system? Both Pika Energy and SolarEdge use a DC bus design philosophy with their proprietary (expensive) home storage batteries that are essentially functionally the same as my Leaf's battery. Seems it should be a matter (likely NOT simple) of proper battery management based on external operating requirements (charging when excess energy is available (solar or grid) and discharging when externally energy is required - operator demands).
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.
Rural cabin with 6750 watts Grid tied PV. Off-grid solar Leaf charging capable (level II).

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