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Marktm
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Leaf Number: 022737
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Re: I made a transparent CAN bus bridge with logging, requesting input

Fri Sep 14, 2018 3:33 pm

I have two solar systems ~ 3900 and 2800 watts. modifying to combining in a high voltage configuration is not too much of a problem (500 VDC+). That would allow me to use my 2012 Leaf in a daily charge mode and have enough energy for nighttime comfort and keep modest appliances going - at least during sunny days. I'd get up to about 20 kWh on a good sunny day. A combo level II (with 7 kw) with an included DC charge controller that accepts a SB50 Anderson would be just the ticket (maybe?).
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.

RkEvHopeful
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Joined: Tue Apr 12, 2011 7:40 am
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Leaf Number: 6154

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

Fri Oct 05, 2018 8:52 pm

Hi Mux,

Can multiple can bus bridges be time synchronized? The idea being you could monitor the OBC, LBC and VCM at the same time and record them all to determine what is needed for an aftermarket OBC.

I'm trying to get the can bus command protocol from the Renesas R5F71424FP microcontroller in the OBC. But it is new territory for me and is going very slowly. Looks like the best idea may be to unsolder the chip from the board. I'm trying to find a programmer for the chip (that can read the program out) and not having much luck.

mux
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Leaf Number: 6177

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

Sat Oct 06, 2018 12:06 am

Hm, that's a good idea actually. Yeah, they certainly could be with some external synchronization source (probably via the serial port). They use crystals for their on-board clock, so during a logging session you should only need to sync once and then just let them freerun, they won't start deviating significantly until many hours of logging.

I'll look into adding that to the firmware. I've actually had quite a few problems with the firmware as of late, and I've been really busy doing all kinds of mechanical work for muxsan, so progress on the public-facing part of the can bridge has been slow.

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

Thu Oct 11, 2018 10:03 pm

Hi Mux,

The Renesas R5F71424FP mcu is locked down against serial extraction. Using a parallel programmer, about $1900USD plus shipping, I could get the binary extracted. Kind of defeats the idea of a low cost replacement charger...

I did find two Chinese companies that will change the CAN bus messages if they are given a CAN bus protocol. The 6.6kW chargers are liquid cooled and "should" fit under the hood of a 2011/2012 Leaf for about $1067USD for the charger plus the extras to install. Since it ties into the inverter wiring there are no concerns regarding charge rate.

So it is back to decoding the charger CAN bus as the lower cost option. Do you know how to intercept the battery LBC without removing the battery pack? If the the OBC, LBC, VCM and EV CAN bus are monitored simultaneously then the OBC CAN messages/protocol can be pulled out.

Adding Chademo charging will require an additional CAN port and more work. Or testing to check if the Chademo messages conflict with the existing EV CAN bus IDs. Why did Nissan add a separate CAN between the OBC and the Chademo charge connector?

mux
Posts: 167
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 Oct 12, 2018 12:19 am

Then there's very little use - just use Brusa chargers instead. Way cheaper and you can triple them up to go three phase.

The easiest way to intercept battery messages is right at the VCM, because nothing else uses the unique battery messages. Only the computed values sent out by the VCM. So just interrupt the CAN bus behind the glove box at the VCM connector and you're golden.

If you really want to be sure to only get the LBC messages, you don't need to remove the battery pack. Just put the car on a bridge or drive it onto some wooden beams if you don't have a bridge at your disposal, disconnect the 12V, go under the car and remove the second belly panel. There you have full access to the battery signal connector, use the pinout in the service manual to tap the CAN bus. If you don't feel secure dangling electronics under the car, extend the wires (try to keep CANH/CANL equal length) and run them into the car through one of the many rubber cable glands.

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

Fri Oct 12, 2018 9:33 am

mux wrote:Then there's very little use - just use Brusa chargers instead. Way cheaper and you can triple them up to go three phase.

The 3.3kW BRUSA NLG513-U1-01A-A01 Battery Charger costs $3591USD plus the extras and the 6.5kW single phase BRUSA NLG664 22kW Battery Charger costs $6239USD. My understanding is the Brusa chargers work as secondary to the OBC and will not work with the Leaf CAN bus without the OBC.

The easiest way to intercept battery messages is right at the VCM, because nothing else uses the unique battery messages. Only the computed values sent out by the VCM. So just interrupt the CAN bus behind the glove box at the VCM connector and you're golden.

I did not realize the VCM was the only device listening to the LBC. Seems like the LBC messages are not needed. If you already know all the LBC message IDs, they can be filtered out.

If you really want to be sure to only get the LBC messages, you don't need to remove the battery pack. Just put the car on a bridge or drive it onto some wooden beams if you don't have a bridge at your disposal, disconnect the 12V, go under the car and remove the second belly panel. There you have full access to the battery signal connector, use the pinout in the service manual to tap the CAN bus. If you don't feel secure dangling electronics under the car, extend the wires (try to keep CANH/CANL equal length) and run them into the car through one of the many rubber cable glands.

This will be the backup plan if needed.

Thanks,
Rex

mux
Posts: 167
Joined: Sat Jan 13, 2018 3:52 am
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Re: I made a transparent CAN bus bridge with logging, requesting input

Fri Oct 12, 2018 9:36 am

Ah of course I should be a bit clearer... I say Brusa, I mean imitation cheap Chinese Brusa clones :) They're about 400 bucks in 100-off, 800ish single unit. You can build an 11kW AC charger for 1500 bucks with those, or 22kW for about 2500. Not quite as cheap as DC quick charging with a CCS retrofit, but close.

RkEvHopeful
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Joined: Tue Apr 12, 2011 7:40 am
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Re: I made a transparent CAN bus bridge with logging, requesting input

Fri Oct 12, 2018 1:43 pm

mux wrote: You can build an 11kW AC charger for 1500 bucks with those, or 22kW for about 2500. Not quite as cheap as DC quick charging with a CCS retrofit, but close.

Do you have the dimensions or a link to them? Are they CAN bus controlled and water-cooled?

mux
Posts: 167
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

Sat Oct 13, 2018 11:39 am

I can't vouch for them personally, but I know two companies that have used/are about to use QNBBM's chargers, e.g. https://www.aliexpress.com/wholesale?ca ... kw+charger

But generally, you have to just look around. They're mostly on alibaba, aliexpress and ebay. Generally if you look for 3.3kw charger or 6.6kw charger you'll find the brusa replacements. And yes, they are generally watercooled and either CAN-controllable or have something that is fairly easy to integrate otherwise. Note that the original Brusas interfere with the Leaf CAN bus because it overlaps some CAN IDs, so you do have to keep that in mind.

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