Charge Speed Reduced because of Solar Array voltage?

[jgd108]

Hi good morning,

Since I have solar I like to be "green" and charge directly from the sun during midday when it produces the max output (I also avoid the roundtrip of energy to SDG&E).

For the past couple weeks, I've noticed the charge drops from 48A to 32A when charging midday on a sunny day.

The Wall Connector is fine (cool, no heat), backed by a new 200A panel with a 60A breaker.

After doing some testing when there's no sun it maintains 48A charging just fine (night or early morning).

I will do one more test today midday, but I've noticed with peak solar the voltages hovers around 243V.

And within minutes the charge rate drops and stays at 32A.

Would the slight increase in voltage be a factor?

The update to the latest firmware 2019.16.2 didn't change anything.

 

[jgd108]

I did some deeper digging into SDG&E online portal, and until May 2nd it was charging at 11.5 kW just fine, but a few days later and till now, it drops to 7.7 kW after an hour of charging. That's from midnight, so no solar.
Probably needs some new parts like I saw in some other posts.

 

[animorph]

It would normally reduce the charge rate if it detected a large (~10V) drop between when charging started (at 0A) and when maximum charge rate is reached. So before it starts charging, check the voltage. Perhaps the solar is allowing the voltage to drop more than the normal grid.

 

[ucmndd]

243v is a perfectly normal/nominal. I don't think there's a correlation here to the solar array.

 

[davewill]

With that message, I'd say the car definitely saw something odd with the incoming voltage and dropped the current. Maybe there's a momentary sag happening infrequently. I have to say that Tesla's algorithm for this is a bit opaque. We know that a voltage sag will trip it, but there might be other criteria.

If you want to diagnose this, you'll probably need a logging voltmeter. A logging ammeter would also be helpful to pinpoint when the current level drops. Some multimeters have an optical port to connect to a PC serial port for logging.

I have TOU, so it's advantageous for me to wait until late at night to charge.

 

[mswlogo]

I wonder if as clouds pass over and it switches back and forth between Grid and Solar it sees a "glitch".
See if it happens on an absolute clear blue sky.

I also charge during good solar to avoid round trip. I've never had an issue. Solar Edge inverter.

I always drop the current on the car or it will exceed the solar production to much, charge will finish to quickly with lots of solar left on the day. So I try to guesstimate the current such that it will finish charging as Solar ramps down. With your 60A setup it will probably finish to quickly (depending on your inverter size) . So it may be doing you a favor anyway.

Here is a fairly well timed Charge during Solar one It's nice having consumption and production in the same app.

 

[jgd108]

Wow thanks everyone, I really appreciate you guys help!
That's awesome.

I did a few more tests now that it's been super cloudy last couple days, and with the voltage being stable at 240V, it drops from 48A to 32A within about 10min after starting the charge and stays that way afterwards. If I stop the charge, and restart it goes again to 48A for a few min. So Solar or voltage fluctuations are not at play.

I've scheduled a Tesla service, and they didn't say it can be done by a ranger so I suspect it will require some component change as others have experienced.

 

[davewill]

... So Solar or voltage fluctuations are not at play. ...

Without a logging meter and plotting the result, I don't think you can conclude that. Maybe you have that from your solar system. Glad someone is going to look at it. I suppose it could be some RF level interference as well.

 

[mswlogo]

Wow thanks everyone, I really appreciate you guys help!
That's awesome.

I did a few more tests now that it's been super cloudy last couple days, and with the voltage being stable at 240V, it drops from 48A to 32A within about 10min after starting the charge and stays that way afterwards. If I stop the charge, and restart it goes again to 48A for a few min. So Solar or voltage fluctuations are not at play.

I've scheduled a Tesla service, and they didn't say it can be done by a ranger so I suspect it will require some component change as others have experienced.

Do you have some other place you can test it? There are a few tests it performs that might be tripping and correct.
You might even try a L2 Public charger. Just need to find one that is above 32A. Ideally 48A or more.

Don't wait for a cloudy day to test if solar system is somehow tripping it, just turn Solar off and remove that variable.

It could be the car, but I wouldn't assume that just yet.

 

[jgd108]

Thanks
I do not know of any L2 Public charger that charges above 32A, most of them are at or below 30A.

At night (midnight) when there is zero solar impact it does the same thing, so Solar is not at play. To confirm it was charging just fine at any time of the day with full on Solar.

It's most likely something faulty with the car, when I googled the Tesla forums they confirmed that "there was a fault in the Power Conversion System and had to be replaced".

 

[srs5694]

Thanks
I do not know of any L2 Public charger that charges above 32A, most of them are at or below 30A.

They do exist, but they're rare. You could check PlugShare for Tesla Destination charging sites; many of them support over 32A charging. Also, some hotels (and likely other sites) have J1772 EVSEs that support over 32A. (I used one of these in New York State less than two weeks ago on a road trip. It was a Clipper Creek EVSE.) I don't believe I've ever encountered a Level 2 EVSE on one of the big networks, like ChargePoint, that provides more than 30A.

PlugShare enables users to enter voltage and amperage data. Many people don't do this, but some do, so you may be able to find suitable locations by scrolling through the check-ins. Of course, an EV like an SR/SR+/MR Model 3 or most non-Tesla EVs will be limited to 32A even if the EVSE supports more, so even if you see 32A being reported, the EVSE may be capable of more.

 

[GoodOmens]

OP any error lights on the HPWC? For instance do you see a single orange flashing light along with the streaming green lights? It's hard to see - the number of flashes indicate different things. I'm having a similar issue (without solar) and service just pushed me 2019.16.3.2 to see if the issue is fixed.

My HPWC has a single orange flashing light (within the green streaming), indicating an issue with the car charger. Going to see if I still have the issue tonight.

 

[jgd108]

They do exist, but they're rare. You could check PlugShare for Tesla Destination charging sites; many of them support over 32A charging. Also, some hotels (and likely other sites) have J1772 EVSEs that support over 32A. (I used one of these in New York State less than two weeks ago on a road trip. It was a Clipper Creek EVSE.) I don't believe I've ever encountered a Level 2 EVSE on one of the big networks, like ChargePoint, that provides more than 30A.

PlugShare enables users to enter voltage and amperage data. Many people don't do this, but some do, so you may be able to find suitable locations by scrolling through the check-ins. Of course, an EV like an SR/SR+/MR Model 3 or most non-Tesla EVs will be limited to 32A even if the EVSE supports more, so even if you see 32A being reported, the EVSE may be capable of more.

Good idea. Not sure if I'll have time until my apt on Saturday.

OP any error lights on the HPWC? For instance do you see a single orange flashing light along with the streaming green lights? It's hard to see - the number of flashes indicate different things. I'm having a similar issue (without solar) and service just pushed me 2019.16.3.2 to see if the issue is fixed.

My HPWC has a single orange flashing light (within the green streaming), indicating an issue with the car charger. Going to see if I still have the issue tonight.

The HPWC has a nice moving green light. I just completed a 45min charge without any issues, with full on solar (with some voltage peaks to 246V). I'll try to not charge until Friday and try one last time for a longer charge and see. It usually reduces the charging speed after <10min.

 

[jgd108]

TLDR Tesla replaced power converter and now it charges fine. Thanks all for the help!

 

[mswlogo]

TLDR Tesla replaced power converter and now it charges fine. Thanks all for the help!

View attachment 419587

Thanks for following up.

 

[bluemonster]

Experienced the same issue. My reduced charge speed was 32A. Mobile ranger tested out car, charger and found nothing wrong. I also tested charge rate at my neighbor's house with the hard wired wall charger and got the same error.
Tech concluded I needed a new PCS as well. My case has been escalated to the engineering team and I am waiting for their approval.