ChargePoint Charging Question

[kevin1956murray]

Below is the relatively quick response I got from submitting Monday's discovery that the "post pause" rate went back to 3kW when the other cord became available. I plan to hit them up in another week or two to check on status. Given that this has been a reported problem since January, I doubt there is any reportable progress in the last several days.



Your request (#ChargePoint Support) has been updated.
1342511: Driver Reported Station Fault

Steve Thomson (ChargePoint Support)

Jun 3, 13:33 MST

Kevin,

Thank you so much for the thorough details you and the other MiEV drivers have discovered. I will bring this up for sure with our software team for them to look into.

Again, thank you for all of the details.

Steve Thomson
Driver Support Supervisor
ChargePoint | chargepoint.com

 

[JoeS]

Quick update:

My friend responded enthusiastically as he has a dual-port EVSE available to him in the lab.

Monkey's on my back to schedule this in - probably week after next. In the meantime, I'll see if I can verify that 36%SoC triggers the 'timeout' in my car.

 

[kevin1956murray]

I look forward to finding out what the pilot signal does during a pause. I appreciate that help.

To close out an older question on that Clipper Creek recall or not: I called a Mitsubishi dealer (service department) and the guy looked the car up using the last 8 digits of the VIN. No recalls showed as 'open'. I asked specifically if the SC-13-001 February 2013 recall shows on the list, and the answer was less definite. He just described some dates and work (one being "computer update"), but none labeled by that recall number (as least that he could quickly see). So I'm thinking that even if that recall were optional, I would hope the database would show it as 'still needed' for my car, so I'm thinking my car likely did get that recall done.

 

[JoeS]

Well, in preparation for going down to ChargePoint I thought I'd verify the 36% point at which the 'timeout' occurs.

I drove my car down to two bars and plugged into my old 240vac JuiceBox (rare for me at home as I use 120vac nowadays), set up my Android with CaniOn to run off a separate USB power source, and went away and then came back to monitor things as the SoC approached 33%...

Sat there watching it go all the way to 42% with no 'timeout', so I went back into the house to see what my house power and JuiceBox monitors were saying and they both showed that the 'timeout' had already occurred much earlier! My uncalibrated guess is that the 'timeout' took place at about 25% SoC.

So, perhaps 36% is not the magic number which instigates the 'timeout'? Never could figure out what triggers it.

Anyone have any suggestions for setting up some sort of automated elapsed-time snapshots or screenshots of CaniOn to capture both the instant that the 'timeout' kicks in as well as its duration?

What I want to do is be able to drive down to ChargePoint and deplete my pack getting there (sufficient to guarantee a 'timeout' will occur) but also not wanting to sit there more than necessary waiting for it once I'm there.

As an aside, I have such a 'timeout' feature on one of my West Marine lead-acid chargers (after about two minutes into a charging session it stops charging and checks for excessive voltage sag before continuing with the charging cycle) , but have not heard of it on any other BEV.

 

[JoeS]

Yet another data point. My car's battery capacity is reading 38.7Ah on CaniOn.

Another data point.

Came back this morning with seven bars. Plugged into 240vac as I needed to go to a meeting early this afternoon. Set Remote for 1-1/2 hours. Charged to 12 bars and 74.5%. Checking my home monitor I see that a six-minute 'timeout' registered fifteen minutes before the car stopped charging, which means it did a 'timeout' somewhere around 65%-70% SoC.

 

[ChrisEV]

The hint by ChrisEV that the timeout occurs at 36% is a great clue, as I had previously never been able to understand when this occurs.

Hi JoeS,

Here's data from my OVMS module the last time it happened in December:

Columns are SoC, charge voltage, charge current and charge state.

You see my plug in at the very top at 15% SoC. OVMS captured moments later when the charge speed was still ramping up at 222V/2A.

It then settles on 218V/14A until it reaches 29% SoC and you see the current drop to 0A.

20 minutes later it resumed charging at 218V/14A.

Here's the session:

This was not a Chargepoint Unit. I think I have a session from a ChargePoint unit I have OVMS logs for.

Edit:

I have 3 timeouts on ChargePoint units back from March.

Happened at 29.5% and 34%. Happened at 29% if I plug in at <20% SoC and 34% when I plugged in at 33%. These sessions were on a busy day with a lot of driving and 2 DCFC sessions before.

The other session I was at the hotel.so I moved the car to the charger in the morning at 36.5%.

It didn't time out until 69.5%. That was about 10 minute time out.

 

[JoeS]

ChrisEV, thanks for that information. So, that timeout does not necessarily correlate to SoC. I will continue monitoring my charging a little more closely, as another variable to look at is the point at which timeout starts after charging commences.

 

[kevin1956murray]

On my MiEV, I am finding that if I take it down to about 18 miles left (about 30% SOC), it is anybody's guess if it will pause or not. If it does pause, it will likely do it within minutes of plugging in. If I take it down to about 10 miles (likely 15% SOC), it will pause for sure, but maybe about a half hour after starting the session.

I do not often get the pause at the higher end, when having started the charge from the low SOC end. In other words, I rarely see two pauses per charge. But I may get a pause when starting from 50%.

 

[JoeS]

So, this morning I met my friend at ChargePoint to do some testing.

ChargePoint HQ has at least two-dozen charging stations in their parking lot in addition to a couple of dual CHAdeMO/CCS DCFCs and a couple of single DCFC units as well. Almost all of the J1772 units had cars plugged into them.

Now, I had planned on depleting my i-MiEV down to below 20% before I got there but the traffic stymied me and I ended up driving much slower than anticipated so I arrived at ChargePoint around 30%. Not to worry...

Commandeered the only available charging spot - a dual-head unit at a disabled parking spot. The other side had a BMWi3 plugged into it, but it was not drawing anything. So, we set up my friend's J1772 adapter box to measure things...

The voltage was 223vac and the pilot was telling the car that 29.9A (edit: correction, as previously I had written 29.5) was available. My friend said that if the other car had been charging that the station's pilot would have told my i-MiEV that only half that would have been available.

Plugged in my i-MiEV and I had CaniOn active to keep an eye on things.

The i-MiEV was drawing exactly 14.0A.

Less than ten minutes into the charging cycle, at 33.5%SoC, my i-MiEV started the 'timeout'! I think the 'timeout' only lasted the requisite six minutes and then the car jumped back up to drawing 14A.

OK, so what does that prove? With the neighboring car plugged in and not drawing any current and no unplugging or replugging of that neighboring car, the i-MiEV behaved normally; i.e., it returned to full power draw.

So, what's next? My friend offered to setup a dual station and J1772 monitor at his home (closer to where I live) as he has a NEMA 14-50 outlet available and we can repeat the test using his car (a Spark) to actively draw power while the i-MiEV is charging and then doing it's timeout. If we see that reduced power draw we can then unplug his car to see if the power jumps back up, all the time monitoring the pilot signal. Our goal is to catch the i-MiEV pulling 1.1kW and see what the pilot signal out of the EVSE is saying.

I'll take him up on it in the near future as we'll continue pursuing this elusive critter (bug).

 

[kevin1956murray]

Thanks for that experiment. But kind of disappointing that the bug of slow charging did not show up.

I don't think I've ever seen my car jump right back to full draw (3kW) right after a pause when it is on a dual cord Chargepoint station. I either have to call in for a reboot (which is not allowed anymore), or go to the car to physically unplug and restart, or hope that a neighboring car will unplug.

Now I'm thinking my car needs some update, or maybe Chargepoint just (in the last four days) had a software update to address the problem, or something else not yet understood is going on.

Below is a charge trace from just 4 days ago, showing the kind of charge that I get from dual cord stations.

 

[kevin1956murray]

Another possibility is that the Chargepoint pilot signal had already "given up on" the car that was plugged into the other line (and done charging), and the software's logic then would have no reason to also reduce the MiEV's charging (by changing its pilot signal too).

Recall that my theory is that during a MiEV pause the software "thinks" the MiEV is done charging, and modifies the pilot signals to get/allow more current available/going to the other car. But if that other car has already finished, then there is no reason to adjust pilot signals further.

So that is another situation that I may be able to replicate. But my wife usually drives the Volt (that I could use as the 'other already finished' car), and finding a half day when she is not using it may be tough.

If it would be at all possible for me to get and use that hardware/meter that could monitor the pilot signal, I would very much appreciate it. I would stand by it and guard it, while monitoring the charge with Chargepoint's app.

 

[JoeS]

With my car I've verified that the 1.1kW problem does not occur when the other port is not being actively used even though the second port's J1772 is plugged into a car.

The way I intend to perform the test is to plug another car into the other port and have it be charging. Then, plug my i-MiEV in and hope it does a 'timeout' and then see if it does not go back to it's full 3kW charge level. Hopefully, it stops at 1.1kW and I'll let it sit at that level for a few minutes and then unplug the other car and see what happens. We (you) already know that unplugging the i-MiEV and plugging it back in again will give it full power.

I just need to run the test and monitor the pilot signal and car's current draw for those different combinations of actively using the other port and I hope I can duplicate your car's behavior in the first place.

As far as measuring the pilot signal ourselves, it should be fairly easy to do if you have a J1772 extension - either open up a connector or slice open the cable and attach this thing to the wiring -

https://www.tindie.com/products/nsayer/evse-tester/

For example, I don't leave home on longer trips without a J1772 extension cord in my car as when I NEED to charge I have no qualms blocking someone who ICEd me and then running the longer cord over to my car to charge.

https://www.evseadapters.com/collections/other-adapters/products/j1772-extension-cord-20-ft

 

[kevin1956murray]

The image/text posted below shows that Chargepoint has "Power Management" for shared stations. This allows more lines/plugs than the supply wires/breakers might be rated for. Given that quite often cars are stilled plugged in when fully charged, that seems like a good scheme, allowing more plugs without greatly increasing installation costs (like fat wires).

Unfortunately for MiEV owners, I believe the pause in charging is interpreted by Chargepoint as that car being done charging, so the power is sent to the other cord(s), if shared. In my experience, after or during a pause, power seems to be shunted away even when no other car is plugged in.

I have pointed out to Chargepoint customer service that this is a problem, but so far there has been no fix to the problem of getting just 1.1 kW after the pause, on dual cord stations.

The description below does not state how the power distribution is controlled. I'm thinking it could be by the pulse width of the pilot signal the station sends to each car, or it might be more directly controlled by some other type of power circuitry within the station.

 

[JoeS]

Kevin,

The first step we need to take is to isolate the source of the problem - specifically, what charging level is the ChargePoint EVSE pilot signal commanding?

With my friend's collaboration I intend to perform the test with his car at the second station (of a dual ChargePoint EVSE) actively charging before, during, and after the i-MiEV goes through its charging 'timeout'.

Hopefully, my car will return from its 'timeout' charging at 1.1kW at which time we can see what current level is being commanded by the EVSE. It will also be interesting in seeing if the pilot signal changes right after the i-MiEV commences its 'timeout'. If, indeed, my i-MiEV is at 1.1kW then we'll see what happens when I unplug the i-MiEV and then plug it back in.

Any other suggestions for structuring this test?

Sure wish I had a sure-fire method for inducing the i-MiEV to go into its 'timeout' (or charging pause or whatever we wish to call it), as at present it's a hit-or-miss time-consuming proposition. I will try using the Remote to stop and restart the charging process, since activating the Remote stops the charging and it then restarts after the programming is done if the ON time delay is set to zero.

In the last two weeks I've been tied up with external obligations and have not had the time to get to this, and next week we're taking off on another 3000+mile Tesla excursion. When I return (mid-July?) I'll schedule a meeting with my ChargePoint friend and hopefully we can continue zeroing-in on this problem.

 

[kevin1956murray]

Joe,

If I think of any test suggestions, I'll post back here.

In my mind, the problem is that I seem to have been unsuccessful getting the attention of anyone technical at Chargepoint. A Driver Support Supervisor (Steve Thompson) thinks the problem will eventually be worked on and solved, but it has been about a half year now with no technical response. Steve says lately that team is pretty busy releasing/implementing some new 'DC 250' station.

So even if we have data that shows the pilot signal from the station is what causes the low post pause charge rate for sure, I'm worried that getting a real fix out of Chargepoint will still be like 'pushing a rope'.

The charging activity history on my account (if Chargepoint were to bother to review it) shows that every time on a single cord station my MiEV returns to 3kW immediately after the pause(s). And every time on a dual cord station it goes to just 1.1kW. So that alone indicates to me that it is not the car alone limiting the charge. (Although it could be some interaction with the dual cord stations.)

I'm thinking now that I may need some type of 'workaround', like some way to still draw a bit of current during the pause (so that the station will still think/know the car is charging). But I do not feel comfortable tapping into both poles of that plug. And even if a 12V accessory would count as a draw (which is unlikely), the cigarette lighter is off when the car is off. Maybe I need a 240V small AC unit hanging in a back window, and a special plug adapter. (I'm kidding.) (But I could use the cool air for when I return to the car.)

 

[JoeS]

Kevin, until we do a controlled test I'd be inclined to not bug ChargePoint about this. I charged yesterday at a dual station and did not see this problem (I don't know if another car used the other port on that station during that time as there was no one there when I started or finished). Forgot to take a screenshot.

...To close out an older question on that Clipper Creek recall or not: I called a Mitsubishi dealer (service department) and the guy looked the car up using the last 8 digits of the VIN. No recalls showed as 'open'. I asked specifically if the SC-13-001 February 2013 recall shows on the list, and the answer was less definite. He just described some dates and work (one being "computer update"), but none labeled by that recall number (as least that he could quickly see). So I'm thinking that even if that recall were optional, I would hope the database would show it as 'still needed' for my car, so I'm thinking my car likely did get that recall done.

I still can't help but wonder if there is a connection because that recall definitely affected the 'timeout' duration in addition to fixing whatever the incompatibility was with the Clipper Creek EVSE .... ooooh, I'll be driving through Auburn tomorrow (home of Clipper Creek) and I'll stop in and see if I can talk with someone in their engineering department and ask them what the issue was. In the meantime, Kevin, perhaps you might stop by the Mitsu dealer and stand over them as they look up your VIN and try to get them to verify that the SC-13-001 recall had been done.

On a brighter note, today I verified that I can induce a temporary charging interruption by the car using the Remote ... programming the ON time stops the charging (and entering zero will allow charging to restart immediately after concluding the next step) so diddling with the Remote to keep it from turning itself off gives us that minute or two that the car is not charging. Completing the process by simply putting in some arbitrary ON-->OFF time and then hitting the top key gets the car charging again. For our purposes, I simply don't know whether this adequately simulates the car's 'timeout' but in the interest of saving time this is the first thing I will try when I get together with my ChargePoint friend.

Has anyone else (other than jray3) seen this problem with a dual-port ChargePoint station? Once again, the problem is that the charge level goes up to only 1.1kW instead of the full 3kW after the car's charging 'timeout'.

 

[kevin1956murray]

Joe,

As you suggest, I will now plan to stop by a Mitsubishi dealer with that particular recall question.

And for simulating the pause with the remote, I am thinking that since the Chargepoint 'charging activity' traces get a read point just every 5 minutes, you may need to fiddle with that remote in order to replicate a 6 minute delay, to ensure that at least one zero reading is uploaded (in case the Power Management software works from uploaded data, rather than some real time sensing at the station).

The fact that you did not get a low charge rate after a pause does seem to implicate my car, since I always get the low rate after a pause even with no other car on the other cord. But I never get the low rate on single cord stations. It may be possible that your station, even though dual cord, was wired up with thick enough wires and two separate breakers, not actually using the shared Power Management kit/philosophy/software. I believe Chargepont has that sharing software to allow less expensive station installations.

The link below shows that the kit to allow a two plug station to share one 40A breaker costs just $50.

https://www.nationalcarcharging.com/products/chargepoint-ct4000-pmgmt

So before going to the trouble of tests, it might be a good idea to know that the charging station being tested is indeed a 'shared' station. A dead giveaway is that when a high drawing Tesla is plugged in next to me, the rate on my MiEV will drop from 3kW to about 2.2kW.

 

[JoeS]

For the test, I'll make sure that Power Share is implemented in the ChargePoint dual-port charging station. I'll also see if there is a software version associated with this feature, what their update policy is, and perhaps a software revision history.

 

[kevin1956murray]

Joe: My MiEV did get the Clipper Creek EVSE update (SC-13-001) on 3/7/13, at dealer #44219.

Long story short: The service guy at the dealer it seems to have always gone to at first this morning did not see it on the list, and he referred me to a different dealership, since this is their last day of operation. The 2nd dealer's service rep did find it pretty quickly and gave me the date and dealer number, so I called back to the first guy to verify that, and he did see it on the list after I helped him zero in with the date.

So it appears to me that there are varying levels of competence/thoroughness when it comes to looking up particular Service Bulletin completions by VIN. Maybe not everybody knows to use cntrl-F or something.

 

[JoeS]

Kevin, good to know your Clipper Creek recall has been installed, but come to find out it does not affect the 'timeout' issue you're having.

Stopped by Clipper Creek in Auburn CA today and had a nice techie talk about the past compatibility issue between the i-MiEV and their EVSE. Turns out it had nothing to do with our 'timeout' problem but instead was a fairly obscure handshake and pilot signal timing issue which was addressed by both Clipper Creek and Mitsubishi. Gave me a nice tour of the production facility and the various EVSEs they're building, a couple of which are power sharing dual-port units. He offered to run the test on my i-MiEV to see how their units deal with the 'timeout' if I were to bring it around... um, they're 170 miles from my home but I might be tempted to make another trip to Lake Tahoe in the i-MiEV... :roll:

Anyway, we're back to needing to perform the dual ChargePoint EVSE test and monitor what that pilot signal is telling our i-MiEV. I'll be home in a few weeks and will try to schedule the test then.