JdeMO for the Roadster?

[Oba]

I'm not sure by JdeMO you mean the part on the car or the charger.

If you mean the charger that is not true. While the car does transfer battery parameters to the charger first to ensure compatibility, once the charge session starts the BMS on the vehicle controls the entire process (including cell / pack conditions). The charger itself only monitors the signal that the vehicle uses to command it (basically current).
https://code.google.com/p/open-chademo/

If you mean the JdeMO equipment installed in the car, that may be true. It might not be the Roadster BMS doing the job.

I think we're confusing elements of how this has to work. The CHAdeMO charger is just that... an off-board charger. This JdeMO equipment is somewhere between the battery and the charger. The vehicle BMS is programmed to control up to 70 amp / 240 volt AC charging (16.8kW / 42 to 56 amps DC at battery voltage from the Roadster onboard charger or three phase motor, depending on which Roadster model), in addition to its many other functions.

I can't imagine that the Tesla firmware is modified to now provide the ability to detect DC charging (which CHAdeMO does not send, unlike CCS / Supercharger which sends a signal of "less than 6 amp", signifying digital communication), in addition to modifying the Tesla BMS power settings (at least 125 amps DC, up to 200 amps DC). I'm sure there are other things I'm overlooking.

It was stated up thread that the RAV4 EV version was parasitical, so it doesn't seem logical that this version for the Roadster would be a different design, correct? In the grand scheme of things, a 400 volt battery is just that. But, as we know from the Tesla CHAdeMO adapter, there must be some basic suite of hardware, including relays.

It sounds like that hardware goes in the boot, which means that the actual inlet could likely go anywhere with enough cable between the hardware / relays and the CHAdeMO inlet. The other end of the hardware would be connected to the battery somehow. That hardware, if operating as a parasite, must be fully capable of controlling both the CHAdeMO charger and adjusting the charge rate by whatever the BMS is reporting concerning the battery parameters.

If if there were no BMS interaction, clearly this could still charge the battery, albeit without the protections of exceeding any limit of the battery. So, my conclusion is that the BMS on the Roadster will be "along for the ride", and not controlling anything except its normal duties of cell balancing, protection from bricking, and blindly reporting all the data that we already know (from service center screen shots) that it reports... pack and cell voltage, temperature, etc.

What more would any off-board charger need to properly charge the battery? By your link, the SINGULAR most important piece of information the off-board charger needs is "how many amps?". It appears any external hardware can provide this information to the charger with the data derived from BMS reporting.

- - - Updated - - -

I drove my new Leaf from San Jose to Sacramento and back with only a short stop in Sacramento. On the way I charged ChaDEMO twice back to back and on the way back I had to charge twice again. I lost a full capacity bar on the Leaf that day. I ended up filing a complaint with Nissan and they attributed it to the ChaDEMO.

This seems to be an "open and shut case". Clearly CHAdeMO destroys batteries after just a couple uses. I recommend switching to Superchargers... just trade that LEAF in and get a shiny new Model S, Model X, or in a few years, Model 3.

 

[stopcrazypp]

I think we're confusing elements of how this has to work. The CHAdeMO charger is just that... an off-board charger. This JdeMO equipment is somewhere between the battery and the charger. The vehicle BMS is programmed to control up to 70 amp / 240 volt AC charging (16.8kW / 42 to 56 amps DC at battery voltage from the Roadster onboard charger or three phase motor, depending on which Roadster model), in addition to its many other functions.

I can't imagine that the Tesla firmware is modified to now provide the ability to detect DC charging (which CHAdeMO does not send, unlike CCS / Supercharger which sends a signal of "less than 6 amp", signifying digital communication), in addition to modifying the Tesla BMS power settings (at least 125 amps DC, up to 200 amps DC). I'm sure there are other things I'm overlooking.
...

I understand all that, that's why I wanted clarification when you say "JdeMO" were you specifically referring to equipment on the car, or are you including the off-board charger. I have no idea how the RAV4 EV JdeMO works (did it involve firmware modifications on the RAV4 EV?), which is why I refrained to say if the Roadster BMS had anything to do with it.

 

[Oba]

I understand all that, that's why I wanted clarification when you say "JdeMO" were you specifically referring to equipment on the car, or are you including the off-board charger. I have no idea how the RAV4 EV JdeMO works (did it involve firmware modifications on the RAV4 EV?), which is why I refrained to say if the Roadster BMS had anything to do with it.

I assume that with the description given as "parasitical" meant that there are no firmware changes. That would be invasive. Plus, if the same equipment is doing more than one car, it seems unlikely that there would be many (or any) changes to the actual cars.

 

[stopcrazypp]

I assume that with the description given as "parasitical" meant that there are no firmware changes. That would be invasive. Plus, if the same equipment is doing more than one car, it seems unlikely that there would be many (or any) changes to the actual cars.

That's probably a good assumption, but going through the FAQ for the RAV4 EV JdeMO doesn't really make it clear if there are any firmware changes. So can't really say for sure.

 

[TOBASH]

I just spoke to Tony. What a great guy! Tony has explained a little bit about how this device works. The device has an 11" x 6" x 5" box. He recommends placement of the box in the trunk. The actual charger port can be placed anywhere. The standard charger port comes with 1 meter of wire. For custom installations, the end user can request additional length for placement almost anywhere on the car.

Ultimately, Tony has a device that works, and he is glad to customize to allow the device to meet the end user needs.

He is quite receptive to input, and he seems as if he will be super friendly and super easy to work with.

He has been following our thread, but apparently is unable to post.

I am very interested in this device, and I plan on purchasing one in the near future.

At some point I will also be installing a CHAdeMO in the new office that I am building. If and when that becomes a reality, I will of course give that information to Bonnie so that she can posted in the appropriate channels for Tesla Roadster owners in the New York area.

Best,

T

 

[AEdennis]

Weird that he wasn't allowed to post here on this, since he is authoritative and some of the members posting on this thread are involved with TMC... Either way, I invited Tony to cross-post on another (more generic) EV forum at SpeakEV.com... Thread for that site is here - CHAdeMO for Tesla Roadster, Quick Charge Power JdeMO deposits | Speak EV - Electric Car Forums

The more Roadster owners hear about it and put their 2¢ in (or more accurately $2,999) the better chance that this will happen. After all, he and his team did make it happen for the 2nd Gen RAV4EV.

 

[dpeilow]

This is the best news I've heard all year.

Funnily enough I was talking to a member of Tesla Engineering staff yesterday at a supercharger. Before he admitted he worked for them, we were talking about the 3.0 battery and the topic of Roadster supercharging. He said it was probably too difficult and expensive and I said I heard a rumour that a CHAdeMO upgrade was coming, to which he thought it would damage the PEM - but admitted that he had not heard of the project and would go check it out.

Then I logged in to TMC this morning to see that the project it likely on. I can't see it damaging the PEM, but I do hope that once word reaches TESLA that someone can do this for < $3k it makes senior management ask themselves why they can't offer supercharging as part of the 3.0 upgrade.

 

[spaceballs]

T... he thought it would damage the PEM - but admitted that he had not heard of it and would go check it out. ...

I've had a good look into the PEM, I see no risk of damaging the PEM via a DC tap/input procedure is done correctly.

 

[mpt]

To add to TOBASH's comments.

The RAV4EV unit listens to the can bus for information on the state of charge and vehicle situation, e.g. is it turned on? Are the batteries warm? etc. It only speaks when needed to, e.g. "Please don't drive away, the CHAdeMO cable is still plugged in!!!" and this they've done by looking for and replicating existing error conditions - in the extreme on the Rav, i.e. the drivers turned the car on, and selected a direction, the unit will issue fake fatal errors to stop the car. With the Roadster, it might be easier as it already has a sensor for 'charging door open' so, Tony can probably simulate that. So, no firmware updates, nice battery condition monitoring and a pleasant user experience.

 

[asgard]

Is the BMS and cooling designed to cope with the heat generated from 400V charging?

 

[mpt]

I think that we have to assume that - no point it creating one that doesn't.

 

[Oba]

Is the BMS and cooling designed to cope with the heat generated from 400V charging?

All charging with ANY battery is done at up to (and even slightly above) battery voltage. The cells in the Roadster are 99 in series multiplied by 4.2 volts maximum. So, yes, over 400 VDC.

The question you needed to ask is "high amperage" going to cause too much heat and overwhelm the cooling system.

 

[asgard]

All charging with ANY battery is done at up to (and even slightly above) battery voltage. The cells in the Roadster are 99 in series multiplied by 4.2 volts maximum. So, yes, over 400 VDC.

The question you needed to ask is "high amperage" going to cause too much heat and overwhelm the cooling system.

Oops yes. You are right. Thanks for reminding

 

[Oba]

Oops yes. You are right. Thanks for reminding

The answer, of course, is that any modern charger (Supercharger, CHAdeMO, CCS, GB/T) can and will adjust current in one amp increments from zero to the maximum possible, all at the control of the vehicle.

So, assuming the vehicle is programmed correctly, the charger will deliver the correct number of amps.

 

[miimura]

You can see some pictures of the production JdeMO parts in a RAV4 EV on that forum here. They decided to have the car ON in the READY state, but in Park and the parking brake set for JdeMO quick charging. That way all the Tesla BMS, cooling pumps, etc. are fully working. The JdeMO controller is listening to the Tesla CANbus the whole time since it indicates current limits for the battery. The Tesla BMS is controlling the charge tapering and the JdeMO controller is just passing the correctly formatted control commands to the CHAdeMO charger.

 

[stopcrazypp]

You can see some pictures of the production JdeMO parts in a RAV4 EV on that forum here. They decided to have the car ON in the READY state, but in Park and the parking brake set for JdeMO quick charging. That way all the Tesla BMS, cooling pumps, etc. are fully working. The JdeMO controller is listening to the Tesla CANbus the whole time since it indicates current limits for the battery. The Tesla BMS is controlling the charge tapering and the JdeMO controller is just passing the correctly formatted control commands to the CHAdeMO charger.

Is the BMS on the RAV4 EV charger aware (meaning it will never issue a current demand that exceeds 10kW of the onboard charger) or will it always note the maximum allowed and let the onboard charger give as much as it can? This is a fairly important distinction, or it would have to be the JdeMO making assumptions about the safe maximum current to charge.

 

[Dave EV]

Is the BMS on the RAV4 EV charger aware (meaning it will never issue a current demand that exceeds 10kW of the onboard charger) or will it always note the maximum allowed and let the onboard charger give as much as it can? This is a fairly important distinction, or it would have to be the JdeMO making assumptions about the safe maximum current to charge.

The BMS most likely broadcasts a "max charge current" which the car uses for both limiting L2 charging as well as limiting the amount of regenerative braking allowed.

So by tapping into the CAN bus and listening for that value along with monitoring other parameters, you can safely charge the battery. To the car, it will just look like you're undergoing regen while standing still if the car is left on like on the RAV4-EV.

 

[dpeilow]

I'm also thinking we Europeans could partner it with one of these for the ultimate flexible charging solution on the road. http://design-werk.ch/wp2/wp-content/uploads/2015/05/MDC22_E.pdf

Come to think of it, QC Power's technique of bypassing the PEM would allow 3 phase charging to be built in to the car - e.g. via a Brusa charger with some CAN control electronics between it and the Tesla PEM.

 

[m0rph]

Miimura made an insteresting remark. In the RAV4, the car must be on (with key) during the charge. Even if a good location can be found for the charge port, I can't see myself leaving the car with the key in there.

 

[dpeilow]

I think the Roadster is different in that opening the charge port door wakes it up. This can probably be faked. Let's wait and see what Tony comes up with.


By the way, CHAdeMOs in Europe...