Metering Charge Energy

[Artax]

Model 3 (not sure about others) does not include a simple way to meter energy consumed from the grid during a charge session. I am currently using the charge cable that was included with the car (plugged into a NEMA 14-50); plan to purchase a Tesla Wall Connector, but from what I have read the connector doesn't have a metering solution either.

I would like to be able to track exactly how much I am paying for power... same way I used to track gas expenditure on my ICE. My utility tells me what my kwH cost is (base and incremental if applicable), so would be an easy calculation if only I knew what the power consumption was..!!

Not holding any hope that this is a priority for Tesla, so wondering if anyone knows of a OEM option..? OR, better yet, is there something I am missing about what is currently available in the M3 s/w?

Thinking about something like this [Link], but is an expensive option.

 

[Tz00]

TeslaFi tells you this info. It seems accurate (less than 1% difference) as compared to my energy meter, which has its own accuracy tolerance.

Here is one sample charge comparison.
TeslaFi energy used: 50.4 kWh
TeslaFi energy added: 47.44 kWh
Brultech energy meter: 50.67 kWh

 

[insaneoctane]

TeslaFi tells you this info. It seems accurate (less than 1% difference) as compared to my energy meter, which has its own accuracy tolerance.

Here is one sample charge comparison.
TeslaFi energy used: 50.4 kWh
TeslaFi energy added: 47.44 kWh
Brultech energy meter: 50.67 kWh

Surprised that Tesla Fi is so close. They only know what the car uses and must estimate what is drawn from the wall. There are several products that will measure the HPWC actual consumption. They will involve CT clamps on the wires and will be accurate. If other folks can confirm the accuracy of TeslaFi because they also have an actual meter, that may be the best compromise because it comes with other benefits.

 

[Tha_Reaper]

My accountant accepts teslafi charging records for tax reimbursement.

 

[srs5694]

I've heard of people using any of four ways to get such data:

• TeslaFi -- As noted earlier, this tool can give you the data; however, TeslaFi is a subscription service, so it'll cost you $5/month or $50/year. There are also privacy/security implications for using TeslaFi, since you're giving a third party access to your Tesla data. This is the only way I know of to account for all the charging you do (at home, at Superchargers, at public Level 2 EVSEs, at friends' or relatives' houses, etc.).
  
• A dedicated meter -- I've seen descriptions and YouTube videos of setups in which an ordinary electric meter is put in-line with the EVSE (or NEMA 14-50 outlet). This will measure the electricity used, but of course it complicates the wiring and adds costs. OTOH, it's the most private way to get this data.
  
• An EVSE with metering -- Some EVSEs, like the eMotorWerks' JuiceBox, can provide data on energy used. This is much like the dedicated-meter approach, but it's cleaner. OTOH, it also adds expense, and depending on the setup, you may be relying on the supplier's service to read the data. Also, AFAIK none of these EVSEs offer a Tesla plug, so you'll need to either use their J1772 plug with Tesla's J1772 adapter or replace the cable with a Tesla cable (and I'm not even 100% sure that the latter option would work).
• Home energy monitors -- Tools such as Sense and Smappee install in or near your breaker box and monitor your house's entire energy use. Many of them can be trained to recognize when specific devices turn on and off, and so can track them individually. Of course, these devices cost money, and you may be giving a lot of data to a third party by using them. I've never used such a device myself, so I can't promise any given one would give correct data on EV charging; but the pattern of power use by a Tesla is pretty distinctive, so I'd expect they'd pick it up pretty quickly.

FWIW, I use TelsaFi and I have an eMotorWerks JuiceNet board installed in a Clipper Creek HCS-40. The figures provided by TeslaFi are almost identical to those provided by JuiceNet. TeslaFi also provides a "charging efficiency" number, which is the kWh added divided by the kWh used. This figure varies from one charge device to another, so I suspect that the car is reporting actual electricity used and added numbers, and TeslaFi isn't just guesstimating the electricity used.

Anyhow, between these four options, you should be able to pick one that meets your needs and preferences.