I just installed a KWh meter for charging my Clarity PHEV. The meter cost $58 plus shipping or $79.99 with free shipping from Amazon. I had to make a quick trip to pick up a part so once I completed the installation I plugged in my charger until it was complete. At that point the meter read 1.61 KWh and a couple of hours later it still read 1.61. The numbers on the meter are very small and I wish I had installed it at eye level so I didn't have to bend over to read it. I make a lot of short trips and don't plan on having the engine start for months at a time. This meter gives me the chance to measure miles/KWh and then cost/mile. I don't know how to get a picture you can click on, so I included the whole thing. In case you can't read the small print on the meter, its an EKM-15E. It only works with 120 Volts but it supports up to 50 Amps.
I've looked in the past for a KWh meter that you can plug your 240v charger directly in to, but without success.
The same manufacturer also makes this one: (Click for full size image) It's $119 including shipping from Amazon.
You can also get it direct from the manufacturer for $90 plus shipping. Shipping to me was $10. https://www.ekmmetering.com/basic-kwh-meter-100a-120-240-volt-3-wire-60hz-ekm-25ids.html
So far I have been averaging about 2.5 miles/KWh, but the temperature has been about 40 degrees so I use the electric heater. Also, I am using a 110 volt charger and have many short trips on a charge which is not very efficient with a 110 volt charger. I'm getting a 220 volt charger with a new KWh meter, but I probably won't get that installed until about the middle of February. Info I have found says the 110 volt charger for less than 2 KWh is only about 70 percent efficient. The 220 for LT 2 KWh is about 84 percent efficient.
After a few more miles I have found when the temperature is around 50 degrees I am averaging about 2.5 miles/KWh. At night when the temperature is around 30 degrees and I am running the heater more and the seat heater, I am averaging about 2.34 miles/KWh.
For 240V I use this hall effect meter, open up the junction box connecting to my HCS-40 and routed one of the hot wires through it (with breaker off of course). Anything that measures power directly will be expensive. https://amzn.to/2HlQnu4
My $20 Kill A Watt meter (see picture depicting total KWH used this month) shows less than a watt being drawn when not charging
Just be aware you might melt your kill a watt using it with an EVSE. Use it short term to measure power, but dont use it long term. Get some hall effect sensor that doesn't have to handle the power directly. However, for 120 V this would be trickier, for my 240 V I have access to wires directly. This type of meter would need an electrician to install correctly. Kill-a-watt is nice as it shows power factor, real power, etc, plug it in once to test, but not sure it is rated for monitoring continuously, people have melted them with EVSEs before.
Viking, the Kill A Watt is rated for 115VAC, max 125VAC, and 15 Amps. Plugs into the dedicated 15 amp outlet that Level1 EVSEs use. They would plug into it; it plugs into wall. Our Level 1 EVSE draws only 12 Amps at 110-120VAC so how could it possibly overload or be dangerous to run continually plugged into the Kill A Watt?? It’s made to do continuous logging with in its power range and it’s working with in the 20/80 rule of breaker to continuous draw (12 amp draw on a 15 amp breaker) Am I missing something here? Or are you talking about adapting a 120v unit to work w 240v? Not sure what you mean. This thread has convinced me to order one for my Level 1 EVSE to track times when I’m not Level 2 charging. Plug n play installation and just $26 for the full featured one. It’s more to get an equivalent one for a 220 v line.
It should be fine, but just as we have seen numerous oulet fires from 12 A EVSE on a 15 A outlet if the outlet is not in good condition, same with kill a watt. At least do me a favor and check plug late on charging cycle. Stop the car, unplug the EVSE. And check that the prongs are not hot (they will be warm). Leaf owners were complaining they would melt sometimes. Point is, if the contact isn't great you will get extra heat buildup. GM got more aggressive with changing charge rate to 8 amp from 12 to avoid issues with Volt. Basically, low quality 15 amp outlets with stab connectors to the back side were causing issues melting down and sometimes catching fire. Does the Clarity actually charge at 12 A over 120 V?
Thanks for the safety recommendations. I’ll be sure to check the temps next charge. I did make sure it’s a dedicated circuit but have noticed when adding dimmers to wall switches that some had rear stab connections and some of those were of the dreaded spring kind. Hmm, maybe the electrician’s apprentice did those. If receptacle gets warm, I’ll definitely check its connections. I’m with you; better safe than sorry. I got the 12 amps from the rating on the back of the Honda supplied Level EVSE.
I have been using Kill-A-Watt to measure my charging. The device is rated at 15 amps and the charger draws about 12A. It never got hot during charging so I think that is fine.
It should be fine, I imagine any melt downs that have occurred were maybe damaged or had a manufacturing defect or something. I just bring it up as something to be aware of. Nice to see the car actually draws 12 A. I was always a bit annoyed when the 2013 and newer Volt's started defaulting to 8 A every charge.
My data is basically the same using the Kill A Watt. I show about 11.5 amps being drawn and get a full 110V charge in about 11.5 hours
I use a Z-WAVE Plug-In energy monitoring smart plug from Aeon Labs. Its rated for 15 amps. It tracks kWh and instantaneous watts used. Works well and I can track what the total wattage is for the month. For some reason my supplied charger only charges at about 1250watts which is about 10.5amps.
Circuits are rated for 80% continuous load so the clarity is right on that edge. I also have melted a kill-a-watt with a large heater I was using on my saltwater fish tank (800 gallons of water). If it’s a new kill-a-watt, newish and properly wired outlet and everything is corrosion free it /should/ be ok. IF it is backstabbed, old and a shared circuit use extreme caution. Also make sure you are not on aluminum wiring! If this is the case just bite the bullet and go to a level 2 evse and have a bew cicuit installed just for the car. I’d you go with a smart charger it will track the usage. On my circuits for my tank I’d oversize the wire at 12 awg, use the screw style backstab outlets and breaker at 15a.
