Bizarre charging behavior

schad

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Something weird is going on with charging in our house.

First things first, last Saturday we got a second EVSE installed (our other EV is an e-tron). Both are the same: Wallbox Pulsar Plus. They are both hardwired to the same 60A circuit. I believe they are set up correctly. The electrician wired everything properly, but forgot to adjust a tiny little dial on the PCB inside. So I shut off the breaker, took them apart, and turned the dial myself. After doing that, I could select the power sharing mode in the app. Everything worked fine until Monday, when I tried to add a second timer.

Now for the weird thing. When we plug in either of our cars, they go green for a few seconds (presumably to gauge the charge rate). Then they go to standby (blue?). Normally, they would stay in standby until it was time to charge. But instead, what's happening is that after a few minutes, I get a notification from the app that the car can't charge in time. Then, the car repeats the charge/standby cycle literally every minute... forever, as far as I can tell. I know this because the Wallbox app sends me a notification every time a charging session ends, so I get a notification every minute.

Last night, after trying a few things, I ultimately unplugged the car, locked the doors, put the key away, and then came back out an hour or two later to plug it back in. At which point it mostly worked. When I woke up in the morning -- the timer is set to 7:40 am -- I had about 20 or 30 "session ended" messages, but the car had successfully charged to 80%.

Today, I decided to just turn off the timers, but discovered that the app wouldn't work. I could update the timers, but I couldn't save them. So I figured I'd just do it from the car. So I went out to the car with my keys. First weird thing: the door handles didn't pop out, even though I had the key in my pocket and the car was unlocked. Had to pull the handle to get in the passenger side. Then I tried to turn on the PCM by hitting the gear icon on the battery/climate display. When I did so, it showed "Taycan" on the passenger display, and a spinning "busy" circle on the center display. It never got past that. I left, unplugged the car, and went inside for a while. I was still having problems with the app. Even though the car was unplugged, the app claimed it was charging at ~1kW, and would be ready in time for its 3:34pm timer (I have no such timer, nor have I ever had a timer for that time). So I went back out to the car. The center display still had the spinning circle on it, even though everything else was dark. So I locked the doors and the screen shut off. Again, I put the key away for a while before going back out.

This time out, the car unlocked when I got into the garage, the door handles popped out, and everything started up just like it always does. I disabled all the charge timers (leaving preconditioning on) from the PCM, and they (eventually) updated on the app as well. I just put on a location-based profile for my house with an 80% minimum charge. The car is still on the general profile, therefore it isn't charging despite being plugged in. I'm hoping it just needs to be driven to realize its profile should change. But worst case, I can just set the general profile to a minimum 80% charge instead.

As I said earlier, my wife's e-tron was also having charging issues. Her car wasn't constantly cycling on and off; it would just error out and not charge (red light on the car, despite EVSE reporting standby). She was able to just unplug and replug, which I guess on the e-tron disables timers. Her car started charging, and stopped when it hit the target with no problems.

I am thinking that what's happening is that the adaptive load sharing characteristics of our two EVSEs are confusing the heck out of our cars' timers, because they try to use the charge rate to estimate when they need to start charging. Whenever one car "tests" the load like this, it's reported to the other car as a sudden drop in available current. The other car wakes up and says, "I need to test the load to update my charging time," and wakes up. They go back and forth like this forever. That's my guess. It would be really, really stupid if the cars were actually doing this, but it's all I've got.

If you actually read through that entire wall of text to get here, I salute you. Does anyone have any ideas what might be going on? It's not a huge deal to lose timers; they really only help us for passively warming the battery on cold mornings. With the weather warming up, that's not as big a deal as it was this time last month. We can live with immediately charging to 80%, in other words. But it would be nice for timers to work.
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fgwinn

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It would be interesting to try charging two Tesla cars in your garage with your setup. Since in the Tesla you schedule the start time not the departure time I don’t think you would see the same behavior.
 

tutis

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@schad ; similar issue here. I also have a Wallbox pulsar plus with load sharing although my neighbours haven’t bought an electric car yet so I’m the only one charging and there’s no ping pong as you describe. See my thread from yesterday.

i think the issue is that the Wallbox takes too long to respond to the probe from the car when it tries to determine power. My Wallbox makes a loud clicking sound when being probed and eventually the car throws a rederror on the charge port with “charging not possible”. Like you I’ve had to disable the timers and resort to general timer but even that so far is proving buggy as the car is reverting to prior settings unprompted.

anyway, please keep us posted on your communication with Porsche and Wallbox. I think they just need to test the two products together with a timer enabled and power sharing enabled (and possibly another car sharing charging power)
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