Apparent rapid discharge while plugged in

Hi, I'm very new with the behaviors of electric cars. We've only had this used 2013 S for a little over 200 miles.

Today I let the car charge up to 80% on its own. Shortly after reaching 80%, I decided I wanted to push it up closer to 100%. With the car still plugged in, I got in, turned it on, and changed it so that it would charge to 100%.

15 minutes or so later, I stepped within Bluetooth range of the car and turned on my phone with Leaf Spy to see how it was doing. I saw that the state of charge was dropping, as were the GIDs and mileage estimate. When I got into the car and turned it on, the instruments in the car agreed that everything had been discharging for the previous 15 or 20 minutes.

I don't remember everything I did, but I at least turned off the car, unplugged the EVSC, and plugged it back in at some point. It seemed to begin to charge *up* again.

Afterward, I checked the smart meter on our house and the kill-a-watt the level one EVSC was plugged into just to verify power was flowing in the right direction. I wish I had done that while it was apparently flowing the wrong direction, but everything seems fine now.

I don't think I yet understand the graph for a Leaf Spy, but I assume it is showing real power and apparent power. I'll post some screenshots below and you can note the time stamps from my phone.

Screenshots:
https://www.dropbox.com/sh/tosxfn7sghqunmr/AABaVg3gcyUoxnUVI1kabpnwa?dl=0

I would definitely love to get people's thoughts on this.

First, when you change anything in the timer, it does not take effect until after you turn the car off.
Second, if you want to charge to 100% after starting an 80% charge, use the overide button to the left of the steering wheel.
Third, any chance that the heater or air conditioner was on?

First, when you change anything in the timer, it does not take effect until after you turn the car off.
Second, if you want to charge to 100% after starting an 80% charge, use the overide button to the left of the steering wheel.
Third, any chance that the heater or air conditioner was on?

Click to expand...

Thanks.

I got the first point.

I have the timer set to off, as we don't have time-of-use metering. Are you saying I could have hit the "timer off" button to get it to resume charging after 80%? It did seem to resume after I turned the car off after changing to 100%. However, that's right when the problem started.

I'm sure the heater or AC wasn't on. I didn't change anything on those settings at any point.

My observation says that it lost about 3% charge in 15 minutes. That crudely works out to a discharge rate of about 3 kW. If that were passing through my 20a/120v circuit, it would've tripped the breaker. Other options are that it shorted through the EVSC or charger, or that it didn't happen. Yet, it did take about 40 minutes at 1200-1300 watts to return it to 80%, and that's consistent.

Is it crazy to think that some programming bug allowed the battery to short through the charger? Not a dead short, but at roughly 3 kW. Are there some less exotic answers to this?

There is no way for the battery to discharge through the charger and EVSE. If the onboard charger had a short circuit that created a 3 kW load on the battery, it would get hot very quickly. A 3 kW load is about right for the cabin heater in a 2013 S so I suspect that the heater was energized.

Gerry

Yes, if the timer off button is pushed while charging, the car will continue charging to 100%. If a timer is set, that button will allow charging to start immediately.

I should have also mentioned that you need to detach the Jplug from the car after you make a change in the timer for that change to take effect.

Don't have any further insight regarding the drop in SOC.

Thanks for the replies.

The heater sure seems like the least exotic answer, but I really don't think it was on. The fan would've been on, as well as the lights. I'm pretty sure I would've noticed those things. But the power drain is about right, according to a couple articles I've read. 4000-4500 watts? Glad we live in a temperate climate.

I may have removed and replaced the J-plug when I was trying to reset everything, so I'll keep it in mind that that's actually part of the process.

Thanks again. I think this'll remain a mystery until it happens again.