Charge flipping between 1 and 2 kW; why?

[Max_G]

I got my M3LR today, and am charging it ATM.
My Zappi will be installed soon. Until then I charge with the provided charger in the trunk.
It is hooked up to a 10A socket, and should provide 2kW/h. While it has done this initially, it is now changing between 1 and 2 kW, and I do not understand why it would do that.
The battery has 66% capacity' the limit is set to 80%.
235V 6/8A 1kW in the phone app display.

 

[cafz]

235V 6/8A 1kW in the phone app display.

This sounds like it has throttled itself down. The car will do this if it detects excessive voltage drop when it ramps the charge rate up, which can indicate a problem in the circuit that's supplying it - a dodgy connection somewhere in the path maybe.

You can increase the current back up to 8A in the charging screen in the car, but if there's really a problem it'll probably go back down again.

(The varying between 1kW and 2kW is the line voltage changing - the actual power is varying around 1400-1500W so when it slips over 1500W the rounded number changes from 1kW to 2kW).

 

[PC__LoadLetter]

When charging my SR+ off my UMC, with its 15 amp tail (the old kind, limited to 12 amps), it'll drop down to 9 amps if I have another device running on the plug next to it, such as a pedestal fan. If I put the fan onto a different circuit, or just switch it off, and stop/start charging the car, it'll go back to 12 amps and stay there.

It sounds like you're trying to draw too much power from that circuit. Or, for whatever reason, the car is worried about the power it's getting.

Consider your options.

You may want to identify what sockets in your house sit on what fuse/circuit (basically switch one off, and go around the house with an electric lamp or something, and note which sockets have stopped working, then switch things around so a different circuit is powered off & repeat the process). Note the capacity of the fuse (15A? 16A? 20A?) and the draw of whatever you're running on that same circuit. At home my car draws 12 amps through a 20 amp fuse. When I visit Sydney it draws 12 amps through a 16 amp fuse. In Sydney it'll trip the fuse if I run the kettle at the same time, so I use the phone app & stop charging when I want to boil the kettle, and hopefully remember to start it again afterwards.

You may want to get a sparky to install another circuit on its own fuse. At least a 15 amp GPO. Ideally 32 amps with one of those round plugs you can buy the matching tail for your UMC fairly easily. If the sparky doesn't know you own an EV, the quoted price will be substantially lower. If asked, it's for, umm, shore power for a Caravan! No, wait, it's for welding! But ideally just specify the exact socket you want and what kind of obstacles exist between the fusebox and the plug site, and get it done.

 

[Max_G]

Thanks for the good explanations...
I thought this to be the case...

This should make sense: we built a new triple garage with auto roller doors. The sparky will come soon to put some power points in, as well as connect the 7kW Zappi. ATM a 20A extension lead is in the garage, with a 10A power board to feed the roller doors, and where I plugged the Tesla in. Yes, Voltage drop is what is at work here. Plugging the Tesla into the 20A lead fixed the problem.

 

[Leeroy]

20A extension lead is in the garage

This is the clincher.

Did exactly the same thing with my own car waiting for the electrician, saw the voltage get down to 217 at once stage then had the same issues you did.
These long extension cords do heat up and cause some noticeable voltage drop.

 

[Wol747]

Sounds as if it's charging at 1 1/2 Kw and it's just the display flipping back and forth between 1 and 2 with tiny changes?