Power Meter on Chargers?

[Rav4evnovato]

Is it too much to ask, for a $1,000 charging station to include a power meter. Leviton sells both separately. Prior to installing a dedicated power meter ($100), any suggestions for accurate measurement of power per charge, or is there an on-board feature for this?

Just leased as of Sept 17. Fully understand, thanks in large part to this Forum, that the EV stands more for experimental, than electric. So far it has been almost as much fun as my American Flyer train set from Christmas 1957.......almost.

 

[TonyWilliams]

I bought several of these for less than $10:

AC 80- 300V/ 100A Volt Amp Dual LED Panel Meter Ammeter With Current Transformer

http://www.ebay.com/itm/AC-80-300V-100A-Volt-Amp-Dual-LED-Panel-Meter-Ammeter-With-Current-Transformer-/200966245803

 

[miimura]

Well, Tony answered the question, but I think the more interesting data to collect is ENERGY not power. That is more difficult than the simple real-time voltage and amperage display linked above.

The cheapest thing I've found is this kit:
Leviton Mini-Meter with CTs

However, you have to count the pulses output by that unit to accumulate the energy. That would be a good job for an Arduino, but definitely not a turnkey solution. The actual meters that do energy accumulation are at least $200 more depending on what, if any, communication ports they have. A complete sub-meter solution with an embedded web server would be about $1,000.

The more common solution is to get a whole-home energy monitor and measure the EVSE circuit separately in that system. There is a thread here talking about those.

 

[TonyWilliams]

There are TONS of the old outdoor glass globe energy meters for $10 - $50 on eBay:

http://www.ebay.com/sch/Electrical-Meters

This guy has lots of these meters:

http://www.ebay.com/usr/e_kid123

1: Meter Socket (Can/Box): Please click the following Home Depot Link to purchase reputable Cutler Hammer, Square D, or Eaton Meter sockets.

http://www.homedepot.com/webapp/catalog/servlet/Search?storeId=10051&langId=-1&catalogId=10053&keyword=meter+socket&Ns=None&Ntpr=1&Ntpc=1&selectedCatgry=Search+All

2: 120 Volts Conversion: If you need to convert meter from 240 Volts to 120 Volts, please ask for it.

3: Discounts: There is discount on purchase of three or more lots. Please ask for it.

4: Pre-Sale Inspection: To arrange for inspection, please use "Ask Seller A Question" or call 315 935 9697. Items are usually available for inspection weekdays (excluding holidays) from 9:00 a.m. to 3:00 p.m.

 

[Charlestonleafer]

I bought several of these for less than $10:

AC 80- 300V/ 100A Volt Amp Dual LED Panel Meter Ammeter With Current Transformer

http://www.ebay.com/itm/AC-80-300V-100A-Volt-Amp-Dual-LED-Panel-Meter-Ammeter-With-Current-Transformer-/200966245803

Would you happen to have a picture of this unit installed with an EVSE?

 

[4EVEREV]

Simple and does full logging

http://www.theenergydetective.com/residential/store/b-5000g.html

 

[Rav4evnovato]

Responses appreciated. Informative and thought provoking. Regarding any on-board ability to determine kW-hours per charge, has anyone had any success in using the entune app for the following: Prior to charging, note the previous EV Efficiency (miles/kWh) from the entune app, and the total miles driven to estimate the total kWh used. How consistent is this to the actual Kw-hours needed for the next charge (using a constant factor for system losses during charge)? I would not expect this method to be highly accurate, but until I decide which monitoring equipment to install, I am interested to hear of any results people have had using this method. Also, realizing that the above may be incorporating the same type of data that is read on the GOM (regarding accuracy).

 

[TonyWilliams]

... Prior to charging, note the previous EV Efficiency (miles/kWh) from the entune app, and the total miles driven to estimate the total kWh used.

That should be a great estimate.

100 miles / 3 miles per kWh = 33.3kWh usable * 1.14 = 38kWh from the grid = 87.6% charger efficiency

 

[Dsinned]

I bought several of these for less than $10:

AC 80- 300V/ 100A Volt Amp Dual LED Panel Meter Ammeter With Current Transformer

http://www.ebay.com/itm/AC-80-300V-100A-Volt-Amp-Dual-LED-Panel-Meter-Ammeter-With-Current-Transformer-/200966245803

Brilliant minds think alike . . . except I bought a slightly different dual LCD display unit (currently only $10, with free shipping).

http://www.ebay.com/itm/Digital-AC-100-300V-50A-Ammeter-Voltmeter-LCD-Panel-Meter-Transformer-110V-220V-/281147947814?pt=LH_DefaultDomain_0&hash=item4175b93b26#

I find the accuracy of this "made in China" inexpensive little meter to be quite good. It displays very close to ~240Vac and ~32.0 from my Leviton 7.7kW EVSE L2 charging station.

I agree with the OP that for a 1000 dollars plus charging station, the least they could have provided is something like this little display in the front panel! :roll:

As Miimura pointed out there is another thread on here for a more elaborate solution using HEM (Home Energy Monitoring) devices like "TED", "EnviR" and others similar in nature, but now real money comes into play (>$100). I have an EnviR and it works well, plus it includes 10 different, wireless, input channels for monitoring power usage of my Central A/C, Furnace, Refrigerator, PV Solar system's output, and numerous household loads.