# EV charger power metering

**URL:** <https://community.homey.app/t/ev-charger-power-metering/59496>\
**Category:** Questions & Help\
**Created:** [January 31, 2022, 1:34pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496 "2022-01-31T13:34:14Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![DidierVU](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/didiervu/32/12458_2.png) [@DidierVU](https://community.homey.app/u/DidierVU)\
**Post date:** [January 31, 2022, 1:34pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/1 "2022-01-31T13:34:14Z")

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Hi there,

I’m thinking about buying a Tesla Wall Connector but this doesn’t has an API to connect with Homey and doesn’t have power metering (AFAIK). I need to measure the total power on this charger so adding a DIN rail module on the fuse (32A) of the charger should do the trick. Would be great if I could see the values in Homey of course.

How do you guys do it?

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**Author:** ![Joost\_Else](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/joost_else/32/17360_2.png) [@Joost\_Else](https://community.homey.app/u/Joost_Else)\
**Post date:** [January 31, 2022, 8:36pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/2 "2022-01-31T20:36:31Z")

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A clamp would do the trick. Aeotec makes a z-wave clamp, check out [Aeotec Home Energy Meter Gen5 - 3 clamp](https://community.homey.app/t/aeotec-home-energy-meter-gen5-3-clamp/23927)

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**Author:** ![DidierVU](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/didiervu/32/12458_2.png) [@DidierVU](https://community.homey.app/u/DidierVU)\
**Post date:** [January 31, 2022, 9:15pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/3 "2022-01-31T21:15:50Z")

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The charger will be single phase unfortunately…

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**Author:** ![peltsi51](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peltsi51/32/12564_2.png) [@peltsi51](https://community.homey.app/u/peltsi51)\
**Post date:** [January 31, 2022, 10:02pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/4 "2022-01-31T22:02:35Z")

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Shelly EM. Not for DIN rail but some DIN adapters might be available.

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**Author:** ![DidierVU](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/didiervu/32/12458_2.png) [@DidierVU](https://community.homey.app/u/DidierVU)\
**Post date:** [February 1, 2022, 5:49am UTC](https://community.homey.app/t/ev-charger-power-metering/59496/5 "2022-02-01T05:49:23Z")

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Looks interesting indeed! Do you have one? Is it possible to view for example the total used energy in 2020 (in insights?)?

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**Author:** ![Joost\_Else](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/joost_else/32/17360_2.png) [@Joost\_Else](https://community.homey.app/u/Joost_Else)\
**Post date:** [February 1, 2022, 11:45am UTC](https://community.homey.app/t/ev-charger-power-metering/59496/6 "2022-02-01T11:45:37Z")

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They also have a one-clamp version =\> [https://www.amazon.co.uk/Aeotec-Energy-Electricity-Monitor-Consumption/dp/B017DV3URS](https://www.amazon.co.uk/Aeotec-Energy-Electricity-Monitor-Consumption/dp/B017DV3URS)

Or you can buy a (much cheaper) clamp and add it to your own hardware. Zappi for example sells a clamp for just under 20 euro: [CT klem 5 meter - Myenergi BV](https://shop.zappi.info/en/ct-klem-5-meter.html) (note: this requires tech knowledge; hardware and programming skills).

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**Author:** ![DidierVU](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/didiervu/32/12458_2.png) [@DidierVU](https://community.homey.app/u/DidierVU)\
**Post date:** [February 1, 2022, 12:04pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/7 "2022-02-01T12:04:12Z")

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Great info! I’ll look into this, thanks 🙂

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**Author:** ![peltsi51](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peltsi51/32/12564_2.png) [@peltsi51](https://community.homey.app/u/peltsi51)\
**Post date:** [February 1, 2022, 1:26pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/8 "2022-02-01T13:26:03Z")

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I have the Shelly 3EM the three phase version of the same equipment. One can see the power and cumulative energy in the insights. In Shelly android or ios app you can get more details based on hour, day, month and year

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**Author:** ![Tirrazo](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/tirrazo/32/55444_2.png) [@Tirrazo](https://community.homey.app/u/Tirrazo)\
**Post date:** [August 13, 2022, 3:21pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/9 "2022-08-13T15:21:00Z")

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I have a “dumb” EV 3 phase charger.

How can the Shelly 3EM be set up to see the energy going through the charger?  
And can I use a Shelly 1 to turn the charger on/off through the pilot cable?

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**Author:** ![Tirrazo](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/tirrazo/32/55444_2.png) [@Tirrazo](https://community.homey.app/u/Tirrazo)\
**Post date:** [August 16, 2022, 10:41am UTC](https://community.homey.app/t/ev-charger-power-metering/59496/10 "2022-08-16T10:41:28Z")

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Internal power meter of my EV charger:

 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/4/5/45d7d077ad5dd94146405cc005919e4df1e2c82b.jpeg)  
 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/3/f/3fe0135e6ca53d85a2190c4db5bfc5eb974da90e.jpeg)

Would it be possible in any way to access this?

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<div class="post-metadata">

**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\
**Post date:** [August 16, 2022, 5:45pm UTC](https://community.homey.app/t/ev-charger-power-metering/59496/11 "2022-08-16T17:45:35Z")

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> [@Tirrazo](#):
>
> Would it be possible in any way to access this?

I really don’t recommend fiddling with the EV charger…

Doesn’t the charger have it’s own dedicated fuse/circuit breaker at the central mains fuse box (inside the house)?  
Then the Shelly 3EM clamp solution is perfect imho, they’re not too expensive, and don’t interfere with the wires and connections.  
Just put the three clamps around the three wires that run to the charger, a bit like this:

 ![](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/3/6/36e557bf159717a279f6199734a0dc9d70e13f10.jpeg)  
Can’t help with the question about switching the unit on/off.  
Isn’t there a contact present, just to use for remote switching?
