Page 1 of 1
Nissan Leaf OBC Gen 2 DC-DC output voltage command?
Posted: Thu Feb 12, 2026 2:19 am
by danjulio
I want to do a better job than Nissan does charging the 12V battery in my EV conversion. To do this I want to control the DC-DC output voltage (based on a charge algorithm with 12V Battery voltage, current and temperature as input). This is a Gen 2 PDM so the command is via CAN. I know it can be done but can't find the specific CAN Bus command to do it. I've searched the usual suspects (Dala's can bus repo, Damien's stm32-vcu code and the various forums). There's a hint in Damien's code that it is ID 0x1F2 but that code doesn't actually set the output voltage, just the Charge Power.
Anybody know how to do this?
Re: Nissan Leaf OBC Gen 2 DC-DC output voltage command?
Posted: Thu Feb 12, 2026 8:27 am
by tom91
Id say, try it. We know how to make it turn on. So just change the content in the sent messages to see what changes and document this and feedback.
The hard work is done for you, the DCDC turns on.
Re: Nissan Leaf OBC Gen 2 DC-DC output voltage command?
Posted: Thu Feb 12, 2026 9:33 am
by J0hannes
Like Dala states in
his repo readme
Browse database file with an editor like Kvaeser database editor 3
The information you need should be there (row 10)
This snip is from EV-can_AZE0.dbc
- image.png (3.91 KiB) Viewed 94 times
In current Zombieverter implementation, there is a fixed value 0xAC for byte 3.
I'm not fluent in Bits and Bytes, but I think this translates to 14,3V as constant voltage request for the DCDC. If I recall, I have measured such voltage from battery when my setup is in run mode.
Interested to see your implementation, if you would be kind enough to share.
This has also been on my list of interests as I also want some smarter charge logic for my 12V battery charging. Especially since I have an electric winch which has a hefty amp draw on high load pulls (+400A)
Re: Nissan Leaf OBC Gen 2 DC-DC output voltage command?
Posted: Thu Feb 12, 2026 4:42 pm
by danjulio
Ok guys, I'll do the work
And I promise to document all. Was just starting the lazy way.
[At the moment] in my conversion - which I need to update here - I'm planning on replacing the Leaf inverter brain board with OI and I'm designing an "Integration ECU" around the Teensy 4.1 to handle the rest of the car, including charge control and the aforementioned 12V battery charging using the Leaf 12V battery temp/current sensor. I designed a couple of 12V battery chargers before and am hoping that knowledge transfers over.