HPWC Energy Usage?

[Stevedore]

Just wondering if I’m misunderstanding something here regarding my MYP’s energy usage.

All of my charging is done at home via my Tesla Wall Connector @48 amps. (Actually, I did try a supercharger once for 15 minutes or so when I first got the car to make sure I knew what I was doing).

My car has 3239 miles on it & shows Total Energy usage as 957 kWh, resulting in 296 Wh/mi. Seems rerasonable, based on what I've read here & elsewhere.

When I query my wall connector with "http://wall.connector.uri/api/1/lifetime", substituting its IP address for “wall.connector.uri”, I get the following report:

{"contactor_cycles":79,"contactor_cycles_loaded":3,"alert_count":3,"thermal_foldbacks":0,"avg_startup_temp":27.1,"charge_starts":79,"energy_wh":1408681,"connector_cycles":44,"uptime_s":16034694,"charging_time_s":373001}

If I understand this correctly, the report shows that my connector has used 1408681 watt hours since new, corresponding to approximately 435 Wh/mi, which seems like a huge disagreement with the wall connector usage.

What am I missing here? Does that “energy-wh”: 1408681 not indicate the total electricity used by the wall connector?

Thanks for any explanation!

 

[esurt]

I'm not sure I understand. Does something say you used 26.4kwh of charging?

Yes, the "energy_wh" metric available via the "lifetime" api showa this difference when you subsract yesterdays reading from today's for exampe, when only half was consumed. If you scroll up you can see that others have also seen double counting issues causing this. It's likely a bug in the firmware I was wondering if anyone found a solution, or had gotten any response from Tesla. I was hoping to use the data from the API instead of a physical meter to monitor usage, but this.is not feasible currently.

My question about idle power was separate from this. I was just a little concreted about the idle current reported via then api (about 0.3A/phase), but if you are correct these readings must just not be very accurate at very low currents.

 

[Sophias_dad]

I was just a little concreted about the idle current reported via then api (about 0.3A/phase), but if you are correct these readings must just not be very accurate at very low currents.

I'd wager that the voltage/current are out of phase with each other and while it may actually be seeing 0.3A/phase, that 0.3A/phase may be occurring at 10V or somesuch.

 

[esurt]

I'd wager that the voltage/current are out of phase with each other and while it may actually be seeing 0.3A/phase, that 0.3A/phase may be occurring at 10V or somesuch.

Not sure about things being "out of phase", but you may have a point re: voltage. I was calculating current power consumption using grid_v * vehicle_current_a * 3, but It may be that it is actually 0.2*3.9 + 0.3*0 + 0.3*4.4 = 2.1W. 2W seems very low though given it has an active Wi-Fi connection and is running a Wi-Fi hotspot.

Another way of thinking about it is that the wall connector is probably only using a single phase for idle operations (Wi-Fi etc.), so power is grid_v * vehicle_current_a * 1, so 70-100W. Unfortunately, I don't have an induction meter, else it would be easy to test.

 

[Consistent21]

I'd like to pull the thread here too as well. Post #2 states (obviously) the Tesla only knows how much power it has received / used, not how much power the Wall Connector has delivered. What that post fails to notice though is that the difference isn't 5 or 10% in the Wall Connector API, it's 47% higher in OPs case. I am seeing similar in my Wall Connector that was installed in January; unfortunately I only learned that these API calls exist last weekend.

In my personal case the "energy_wh" number in my Gen 3 Wall Connector, if I use the average consumption of my car, says it's delivered enough energy to drive 832 miles further than the car odometer reading - a 32% difference. If I look just at Charge Stats in the Tesla app it says my 2023 charging has been 517 kWh vs. the Wall Connector stating 824 kWh lifetime (it was installed on January 3) - that's a 61% difference (now, there were two days in 2023 where I charged before I had the Wall Connector installed; this however would actually make the delta look better; also, I charged twice at Volta free chargers, but that was a total of only 3 kWh)! What I'm wondering is if the Wall Connectors are delivered with some number already populated in the "energy_wh" column, like from factory testing during production, and this is skewing the numbers? Also, the session_wh number aligns exactly to what the car says, so is that actually delivered energy or is that actual energy use?

I've searched high and low on the internet about this and no one seems to be speaking about it. This kind of a discrepancy, if accurate, ought to be serious serious news, so I personally think something else is going on here. I'm definitely going to pay very close attention to this from now on though.

Tesla Model 3 with LFP batteries. I charge daily to 100% and hav been looking at the Energy tab in the Tesla app. One day it over reported the usage by almost double compared to the car after a long trip. I was confused for a while but think I found the issue. The app seems to always report as if it's running at max charging, i.e. 32 Amps. I charge at 16 Amps to save wear and tear on the components. If I divide by 2 it's a lot closer.