Difference in charging statistics between Tesla App and EEVEE. Who to believe? Model X 90D 2016

[abalexab]

I would like to address everyone who uses the EEVEE program and knows how the statistics of the Tesla application are kept. I have encountered a very strange problem. The charging statistics in both programs are different and significantly different. And I understand if it was always more in one program and less in the other. But here everything is completely unpredictable. For example yesterday the Tesla showed 38 kW taken from the supercharger and EEVEE showed 36.59
Last week Tesla read 61 kW and EEVEE read 63.65 kW.
How do I explain this difference and which statistic to believe? I understand that Space X can land a launch stage from 120 km altitude on a barge in the open ocean, but why can't Tesla calculate exactly how much its car takes when charging and where that electricity goes (battery heating, cabin cooling/heating), screen, etc. I understand that the engineers in these companies are different, but to be so...
I have a free supercharger and so I don't know how much my car REALLY takes when charging since Tesla doesn't charge me for it.

 

[DCGOO]

I cannot comment on the EEVEE program you mentioned because I do not use it. In fact I never even heard of it before your inquiry. But I can tell that the Tesla app tracks quite accurately. I have a separate electric meter installed on my garage, which is only used to charge my cars. If the total of both my cars as detailed in the Tesla app, indicate 22 KWh was added, that is exactly what my electric meter indicates. However, my electric utility rounds to the nearest single kWh, as does the Tesla app.

FWIW my local electric utility has a great plan for EV charging, off-peak. AES Indiana (FKA Indianapolis Power and Light) does not offer a TOU plan, flat rate under 12¢ per kWh normally. But they have a special tariff for EV charging that does, off peak rate is only a scorching 2.7¢ per kWh. In the summer months it is even less @ 2.3¢ per kWh, although the off peak hours are somewhat less in the summer. You must have a separate meter and utility drop to enroll in the service which is all free from the utility. But you will have to pay a licensed contractor to install a meter base, riser and load center. That ran me $3,000 for that, including two 60 amp circuits to my wall connectors, which I hooked up myself.

AES Indiana only serves Marion County Indiana (Indianapolis), and a few areas just outside the county.

I would like to address everyone who uses the EEVEE program and knows how the statistics of the Tesla application are kept. I have encountered a very strange problem. The charging statistics in both programs are different and significantly different. And I understand if it was always more in one program and less in the other. But here everything is completely unpredictable. For example yesterday the Tesla showed 38 kW taken from the supercharger and EEVEE showed 36.59
Last week Tesla read 61 kW and EEVEE read 63.65 kW.
How do I explain this difference and which statistic to believe? I understand that Space X can land a launch stage from 120 km altitude on a barge in the open ocean, but why can't Tesla calculate exactly how much its car takes when charging and where that electricity goes (battery heating, cabin cooling/heating), screen, etc. I understand that the engineers in these companies are different, but to be so...
I have a free supercharger and so I don't know how much my car REALLY takes when charging since Tesla doesn't charge me for it.

 

[abalexab]

I cannot comment on the EEVEE program you mentioned because I do not use it. In fact I never even heard of it before your inquiry. But I can tell that the Tesla app tracks quite accurately. I have a separate electric meter installed on my garage, which is only used to charge my cars. If the total of both my cars as detailed in the Tesla app, indicate 22 KWh was added, that is exactly what my electric meter indicates. However, my electric utility rounds to the nearest single kWh, as does the Tesla app.

FWIW my local electric utility has a great plan for EV charging, off-peak. AES Indiana (FKA Indianapolis Power and Light) does not offer a TOU plan, flat rate under 12¢ per kWh normally. But they have a special tariff for EV charging that does, off peak rate is only a scorching 2.7¢ per kWh. In the summer months it is even less @ 2.3¢ per kWh, although the off peak hours are somewhat less in the summer. You must have a separate meter and utility drop to enroll in the service which is all free from the utility. But you will have to pay a licensed contractor to install a meter base, riser and load center. That ran me $3,000 for that, including two 60 amp circuits to my wall connectors, which I hooked up myself.

AES Indiana only serves Marion County Indiana (Indianapolis), and a few areas just outside the county.

Thanks for such detailed explanation. unfortunately In NYC electricity much more expensive and electrics asking around 6000 for separate meater installation and registration with local authorities. Elso try EEVEE. This is free app (no monthly charges as rest of the programs ) and giving you much more details plus keeping trace and history of all your consumptions and charges. It’s requiring access from Tesla to your car and passing access to all data to app.

 

[brkaus]

Perhaps you should contact EEVE?

 

[abalexab]

I cannot comment on the EEVEE program you mentioned because I do not use it. In fact I never even heard of it before your inquiry. But I can tell that the Tesla app tracks quite accurately. I have a separate electric meter installed on my garage, which is only used to charge my cars. If the total of both my cars as detailed in the Tesla app, indicate 22 KWh was added, that is exactly what my electric meter indicates. However, my electric utility rounds to the nearest single kWh, as does the Tesla app.

FWIW my local electric utility has a great plan for EV charging, off-peak. AES Indiana (FKA Indianapolis Power and Light) does not offer a TOU plan, flat rate under 12¢ per kWh normally. But they have a special tariff for EV charging that does, off peak rate is only a scorching 2.7¢ per kWh. In the summer months it is even less @ 2.3¢ per kWh, although the off peak hours are somewhat less in the summer. You must have a separate meter and utility drop to enroll in the service which is all free from the utility. But you will have to pay a licensed contractor to install a meter base, riser and load center. That ran me $3,000 for that, including two 60 amp circuits to my wall connectors, which I hooked up myself.

AES Indiana only serves Marion County Indiana (Indianapolis), and a few areas just outside the county.

One more question. I know when car plug to power source for long time (which is recommende) and battery charged to pre-set level car still taking some energy to compensate battery drain and some internal processes. How this reflected in to your Tesla statistic? As I mention - I have free supercharger and 99% of my charges there.

 

[DCGOO]

One more question. I know when car plug to power source for long time (which is recommende) and battery charged to pre-set level car still taking some energy to compensate battery drain and some internal processes. How this reflected in to your Tesla statistic? As I mention - I have free supercharger and 99% of my charges there.

I can not answer your question. This is the first instance I've heard of free access to a Supercharger, other than older models. Even those are subject to idle fees, so I cannot say.

 

[abalexab]

Look like I found answer on my question. It’s following:

The charging efficiency is the ratio between the energy consumed by the charging process and the energy saved by the battery.

The EEVEE app shows the charging efficiency as percentage for every charging event in the History tab.

In this example, the charging event consumed 10,77 kWh and the battery saved 9,62 kWh of that energy. That means that 89% of the energy coming from the power grid is transported and saved in the battery. That also means that there is an energy loss of 11%.

Any loss of electrical energy comes back as heat. During the process of electric charging, the hardware components heat up and this means a loss of energy. Any additional losses are caused by the degradation of any hardware components, like for example the battery and the battery charger. A scientific research from the Department of Electrical and Computer Engineering, University of Delaware, USA in May 2017 shows that such energy losses during the electric charging process can go up to 36% and that the predominant losses occur in the electronics used for AC-DC conversion.

We know that the charging efficiency vary depending on the charge current and on the battery state of charge (SOC).