My wife plugged in to the EV charging station at work for the first time today. She was supposed to receive an email when the charge finished but wasn't notified because there was a still a trickle charge being registered by the EV station even though the battery was full. This led me to wondering about two things. How much energy is being drawn when the cord is plugged in to the Prius but it is not actively charging. Also, how much power is being used by the power cord when it is plugged in to the wall but not plugged in to the Prius. I'm thinking that depending on how much energy is being used, it might be worth the hassle of unplugging it from the wall when I'm not actively charging the car. Anybody have a watt meter that can measure this?
I see about 1 watt on my Kill-a-watt. How do you get as accurate as 1.1 watts? Yes, you can let it sit for many hours and see how many kwh and how much time. But at this low wattage I find that the k-a-w tends to be measuring itself as much as anything else. Just the k-a-w meter takes a most of a watt by itself, it seems sometimes, based on my smart meter. I do note that my PG&E smart meter says about 1400 watts (delta from base) while the k-a-w says 1355w or so. So it is not really that accurate, IMO. I'm going to cross check with another watt meter later this week. Mike
dono how, because I was just checking my paperwork of data when I hooked up KAW last summer, I had 1.1 watts when the brick is unplugged it reads 0.0 watts
Cool, thanks for the info. I assume those measurements are without being plugged into the Prius. Do you know if there is any increase when it is plugged into the car but not charging?
actually my data was with the brick plugged in both to 120 and the J1772 plug after the led on the charger door has gone off
I think some devices have a lower threshold...if the value is less than this it reads zero. Maybe a rounding function. I know my house smart meter will read zero if the load is less than 10 watts. But If I turn on a 15 w load, I see 15. If I then turn on an extra 1 or 2 watt load it will read 16w or 17w. But turning on just the 1 or 2 watt load or even a 5 or 8 w load it reads zero. But back to the PIP EVSE. I just read 1.4 watts using a more expensive (accurate?) meter (Watts up Pro). At least it shows one more decimal point than the KAW meter. I got 0.011 amps at 122.5v which it rounded up to 1.4w. Tonight I'll see what it reads over a whole day. Mike
Probably bad software on their part. When my car is finished at a ChargePoint station, I receive the following text message: ChargePoint: Your vehicle plugged into CIVIC CENTER / CITY OF ALAMEDA is drawing very little power and may be fully charged. Call 888-758-4389 for help.
I borrowed a Watts up Pro meter (more expensive than a Kill-a-watt) and maybe more accurate. When I look at the reading of the Toyota supplied EVSE charger cable it says 1.4 watts. Actual amps x volts is about 1.35 w. But when I leave it plugged in for a day or so the average is less than a watt...about 0.94 watts (one reading was 13.7 w-hrs over 14.57 hours). When the cable is plugged in to the PIP, and the timer mode set, the reading goes up to ~2 watts during the ~10 seconds while the PIP does whatever is does during this setup time, then it drops back down to ~1.4 watts. During charging I read 1380 watts (varying up/down by 5-10 watts) with the WUP, while about 1355 with my KAW. My PGE smart meter read about 1390 watts (delta)...the amount being billed. Mike
