How to see charge rate

[gpsman]

How do we get to see charge rate (kw) from inside the Bolt? Does this only work when on DCFC?

For example I went to a public L2 charger.
The bolt screen in front of the steering wheel only said "charging" and "done by" time.

Only after an hour I surmised it was only a 3.3 kw charger due to the slow rate the miles were going up.

Thanks.

 

[dandrewk]

Turn the car on while it is charging (don't worry, it won't let you drive). You'll see the charge rate on the instrument cluster (DIC).

 

[like2bike]

For example I went to a public L2 charger.

Please remember that for L1 and L2 charging, the "charger" is part of the EV. The charging station is called an "EVSE". The EVSE does tell the EV how much current is available though. L3 charging stations can be called chargers since they are providing power at the battery voltage.

 

[gpsman]

Turn the car on while it is charging (don't worry, it won't let you drive). You'll see the charge rate on the instrument cluster (DIC).

Well when I did that (pressed the start button) it immediately said "charge interrupted".

This was a charge point.

Also the Onstar texted me saying charge was interrupted. As soon as I turned the car off, charging resumed.

 

[dandrewk]

Hmm, well that definitely didn't happen when I tried it in my garage. It verified a 7 kw charge rate.

 

[wwhitney]

Possibly the difference is brake depressed or not (when hitting the power button while connected to a charging station)?

Cheers, Wayne

 

[phil0909]

When I did this in my garage, the display did show an interruption, but the charge rate did also appear on the other display. Perhaps there is a momentary interruption and then charge resumes. The charge rate shown fluctuates between 7kw and 8kw on the display for my L2 device, which seems about right.

 

[Pigwich]

That's weird that the car stopped charging - I sit there in the vehicle sometimes, climate control running, radio on and charging away on DC. Maybe the fast charger is set up to read the state of the ignition and stop? Never had this problem however, and the standard J1772 doesn't have the means to communicate ANYTHING about the car to the charger, so it couldn't have been that.... Could you describe the set up in a bit more detail?

 

[SeanNelson]

...and the standard J1772 doesn't have the means to communicate ANYTHING about the car to the charger, so it couldn't have been that....

If that's true then why is it that when I watch these videos of people doing DC Fast Charging the charger's screen shows the SOC percentage of the battery?

 

[JeffN]

...and the standard J1772 doesn't have the means to communicate ANYTHING about the car to the charger, so it couldn't have been that....

If that's true then why is it that when I watch these videos of people doing DC Fast Charging the charger's screen shows the SOC percentage of the battery?

The usual AC charging communication is mostly from EVSE to the car and it is communicated in a primitive analog way that was easy to create dumb circuits for. Optionally, a newer digital protocol can be used to communicate information in both directions but this essentially is never done except for DC charging. DC charging requires the use of digital communications.

Thus, the car can tell the DC charger what its state of charge is.

The digital communications mechanism for CCS uses the same messaging formats as the Internet.

 

[SeanNelson]

...and the standard J1772 doesn't have the means to communicate ANYTHING about the car to the charger, so it couldn't have been that....

If that's true then why is it that when I watch these videos of people doing DC Fast Charging the charger's screen shows the SOC percentage of the battery?

The usual AC charging communication is mostly from EVSE to the car and it is communicated in a primitive analog way that was easy to create dumb circuits for. Optionally, a newer digital protocol can be used to communicate information in both directions but this essentially is never done except for DC charging. DC charging requires the use of digital communications.

Interesting, thanks for the info. It seems obvious to me they should make this new protocol available to L1 and L2 chargers as well if both the EVSE and the car support it. That would make a "smart" charging station in your garage (i.e, one that could communicate with your home network via a wired or wireless connection) a lot more useful and reduce your reliance on an OnStar subscription to get information about how your car is charging.

 

[Pigwich]

If that's true then why is it that when I watch these videos of people doing DC Fast Charging the charger's screen shows the SOC percentage of the battery?

Because CCS isn't a regular "J" plug. When using CCS, it takes the J1772's "pilot" pin and instead runs an implementation of powerline ethernet over it (green PHY or some BS) and THAT'S how the station communicates. I'm not sure you can run PHY over the pilot while using it as a pilot. Maybe you can, but the frequency is 1khz, which isn't a normal frequency for PHY to piggyback on, and running PHY might make the car mad, because it would have to communicate during the "low" parts of the PWM signal, which could potentially cause the car to ask for more power than the station can offer. At any rate, a regular 220V charger can't communicate SOC with the car, but a CCS can.

 

[SeanNelson]

If that's true then why is it that when I watch these videos of people doing DC Fast Charging the charger's screen shows the SOC percentage of the battery?

Because CCS isn't a regular "J" plug. When using CCS, it takes the J1772's "pilot" pin and instead runs an implementation of powerline ethernet over it (green PHY or some BS) and THAT'S how the station communicates. I'm not sure you can run PHY over the pilot while using it as a pilot. Maybe you can, but the frequency is 1khz, which isn't a normal frequency for PHY to piggyback on, and running PHY might make the car mad, because it would have to communicate during the "low" parts of the PWM signal, which could potentially cause the car to ask for more power than the station can offer. At any rate, a regular 220V charger can't communicate SOC with the car, but a CCS can.

Thanks for expanding on JeffN's answer.

With a trivially smart microprocessor at each end it should be pretty simple to come up with a safe recognition protocol that would let both sides use the pilot signal to communicate the intention to the use the new method, or fall back to the old method if the other party didn't support it. That would open up the L1/L2 world to support some of these newer features.

 

[Pigwich]

With a trivially smart microprocessor at each end it should be pretty simple to come up with a safe recognition protocol that would let both sides use the pilot signal to communicate the intention to the use the new method, or fall back to the old method if the other party didn't support it. That would open up the L1/L2 world to support some of these newer features.

I agree - The problem is that the Homeplug standards are a disaster of license restrictions, etc. SUPPOSEDLY the spec went out as an open standard late last year, but no hint of actual documents being released, plus Broadcom is involved, and in that world, nobody wants to talk to you unless you're Nintendo or Samsung. We'll see what happens. There are people that have hacked PHY adapters. The home-built submarine drone community is one, but that's only part of the puzzle. Getting access to the car is another thing entirely, and remember, we needed an ACT OF CONGRESS to allow repair shops to get access to the same documentation that dealership shops had, so expect an uphill battle concerning network access to an EV without NDAs that threaten your first born, and then once that happens, which it will eventually, there will be hordes of security flaws uncovered. Expect an uphill battle. Who remebers OwnStar? or the Toyota spaghetti code debacle?

https://arstechnica.com/security/2015/07/ownstar-researcher-hijacks-remote-access-to-onstar/

http://www.safetyresearch.net/blog/articles/toyota-unintended-acceleration-and-big-bowl-%E2%80%9Cspaghetti%E2%80%9D-code

Automobile manufacturers are just now learning to take the computer parts of the car seriously, but not before they killed a few people.

I'm not sure what the deal is with the LEAF - I know CHADEMO uses CAN bus to communicate, and that code is long since documented and implemented in the open, but it's a different creature. I suspect that (if they were smart anyway, jury is still out) that the network coming out of the charging port on a CCS vehicle is fire-walled (or air-gapped) from the internal network of the vehicle. Were that not the case, a bad actor could do things like...oh, turn off the air bags or worse when they plug in to a charger with bad intent.

At any rate, yes, a dumb charger shouldn't take much to make it smart, but there are a LOT of man-made obstacles in the way currently. I'd like to see it happen some day, since it would allow a lot of really great things to be implemented, especially in large charging installations and power budgeting.

One day