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Discussion Starter · #1 ·
I have re-posted my post from another thread to enable a wider audience and awareness as well as to invite discussion....

I am wondering if anyone else is experiencing this?

Could I possibly have a faulty granny charger?

7Watt consumption seems excessive for what appears to be just illumination of the "power" graphic.

============================================================================

Interestingly, I discovered that the e-niro granny charger uses power even when not connected to the car.馃

I have it supplied through a plug-in energy monitor so that I can log my charges on a spreadsheet.

With my previous EV I left the granny charger plugged into the household socket all the time and just plugged the cable into the car when needing to charge. There was no power usage when not plugged into the car.

Over a 24 hour period the power consumption meter showed 0.17kWh consumption.馃槼

I now switch off the supply at the wall when not charging, but this means losing the cumulative reading馃ゴ

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144404
 

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E-Niro 64kWh '4' since 9/20 (was Prius)
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7W isn鈥檛 a huge amount but is certainly a bit more than I would have expected it to draw in standby. There is a lot more stuff inside that EVSE box than just the LEDs but still I reckon it should be much less than that. If it really is taking 7W the case would feel very slightly warm to the touch (after it鈥檚 been on an hour or more).

Are you sure the energy meter was reset to zero at the start of the 24h period?

I wouldn鈥檛 trust that power meter too much. Especially at low power draws like this. Does it not have other modes so you can display the instantaneous power draw in W or kW? They usually do have these modes selectable with the buttons.

I very much doubt there will be anything wrong with your granny lead. Later today, I will get mine out from under the floor and measure it for you. I expect rather less than 7W, but we鈥檒l see. Peter
 
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Discussion Starter · #4 ·
Is ~60p a month a real inconvenience?
My concern is that there may me an issue with my charger, hence why I would be interested in the experience of other users.

Does it not have other modes so you can display the instantaneous power draw in W or kW?
only cumulative consumption afaik, I misplaced the instruction leaflet some years ago馃ゴ

I will get mine out from under the floor and measure it for you.
I'd appreciate that for comparison, thanks.

Are you sure the energy meter was reset to zero at the start of the 24h period?
Yes, it was at zero. I'll reset it overnight tonight to see if I get the same result.
 

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E-Niro 64kWh '4' since 9/20 (was Prius)
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Ok, A conclusive result. Bottom line is I think you need to get a more recent technology energy meter. It likely can鈥檛 cope well with reading true power when the power factor is not close to 1. (The power factor in this case is 0.12 apparently, so it is a very reactive load). Your meter might work ok into purely resistive loads such as a kettle, toaster or incandescent light bulb for instance. Or it might just be inaccurate at very low wattage measurements. It might be fine with bigger loads?

I have two. An older one which works very well but only reads in resolution steps of 1W. A much newer one which reads to a finer resolution of 100mW steps. The old one alternates it鈥檚 reading between 1W and 2W. The newer one reads steady at 1.6W. So they effectively concur that it takes just ~1.6 Watts.

I think you can happily leave it powered on if you wish to. By the way, my newer meter can store cumulative readings even when it鈥檚 turned off. In fact, I have to remember to reset it before use if I need the cumulative amount recorded. HTH
Peter.
Old meter snap 1
144451


Old meter snap 2
144452



New meter gives rock steady 1.6W power consumption. (no change with time or 6/8/10 Amp settings)
144453



Display showing current and power factor readings
144454



Display showing Voltage and frequency readings.
144455
 

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Ok, A conclusive result. Bottom line is I think you need to get a more recent technology energy meter. It likely can鈥檛 cope well with reading true power when the power factor is not close to 1. (The power factor in this case is 0.12 apparently, so it is a very reactive load). Your meter might work ok into purely resistive loads such as a kettle, toaster or incandescent light bulb for instance. Or it might just be inaccurate at very low wattage measurements. It might be fine with bigger loads?

I have two. An older one which works very well but only reads in resolution steps of 1W. A much newer one which reads to a finer resolution of 100mW steps. The old one alternates it鈥檚 reading between 1W and 2W. The newer one reads steady at 1.6W. So they effectively concur that it takes just ~1.6 Watts.

I think you can happily leave it powered on if you wish to. By the way, my newer meter can store cumulative readings even when it鈥檚 turned off. In fact, I have to remember to reset it before use if I need the cumulative amount recorded. HTH
Peter.
Old meter snap 1
View attachment 144451

Old meter snap 2
View attachment 144452


New meter gives rock steady 1.6W power consumption. (no change with time or 6/8/10 Amp settings)
View attachment 144453


Display showing current and power factor readings
View attachment 144454


Display showing Voltage and frequency readings.
View attachment 144455
Ok, A conclusive result. Bottom line is I think you need to get a more recent technology energy meter. It likely can鈥檛 cope well with reading true power when the power factor is not close to 1. (The power factor in this case is 0.12 apparently, so it is a very reactive load). Your meter might work ok into purely resistive loads such as a kettle, toaster or incandescent light bulb for instance. Or it might just be inaccurate at very low wattage measurements. It might be fine with bigger loads?

I have two. An older one which works very well but only reads in resolution steps of 1W. A much newer one which reads to a finer resolution of 100mW steps. The old one alternates it鈥檚 reading between 1W and 2W. The newer one reads steady at 1.6W. So they effectively concur that it takes just ~1.6 Watts.

I think you can happily leave it powered on if you wish to. By the way, my newer meter can store cumulative readings even when it鈥檚 turned off. In fact, I have to remember to reset it before use if I need the cumulative amount recorded. HTH
Peter.
Old meter snap 1
View attachment 144451

Old meter snap 2
View attachment 144452


New meter gives rock steady 1.6W power consumption. (no change with time or 6/8/10 Amp settings)
View attachment 144453


Display showing current and power factor readings
View attachment 144454


Display showing Voltage and frequency readings.
View attachment 144455
I get 1.7W on mine -- through what looks like the same meter.
 

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Discussion Starter · #7 ·
when the power factor is not close to 1. (The power factor in this case is 0.12 apparently,
What is this figure and what does it mean?

Yes, my meter is probably 10+ years old ( i think it was purchased from Aldi), so as you say, not up to current technological standards.

I guess it is more than adequate for the purpose of logging my home charging.

Thank you for taking the time to investigate and for posting the results. Much appreciated(y)
 

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Kia e-Niro 4 MY20, Zoe Z.E.50 GT Line
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Power factor is something I鈥檝e always struggle to get my head around. You can read about it on Wikipedia.

I have a sort of idiot鈥檚 working understanding of this that probably doesn鈥檛 stand up to scrutiny. In the example of a small domestic device that has a low power factor, it鈥檚 probably caused by a power supply that only draws power at the peaks of the ac waveform, compared to something like a filament lamp that draws power across the whole waveform.

On a large scale this causes problems for the utility which has to provide more power overall to make up for the fact it鈥檚 not being used evenly.
 

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E-Niro 64kWh '4' since 9/20 (was Prius)
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you're not kidding o_O馃ゴ
I wish I'd never asked
AC theory is a surprisingly complex subject. I鈥檓 no expert on it either.
However, maybe to get a loose mental handle on it......

1. With DC circuits all is nice and simple Power (Watts) = Amps times Volts.
2. With AC RESISTIVE loads, just the same just like above (PF is then Unity or 1).
3. With REACTIVE loads (Capacitors or Inductors Or active non linear devices (diodes, switching transistors etc. etc) Everything can change and the simple power = VxA rule goes right down the bog (unless the PF is still Unity, which is quite rare).

The reason situation 3 differs is that the Voltage waveform and the Current waveform are no longer in perfect sync with each other. The Current can significantly lag (inductive load) or significantly lead (capacitive load) in time with respect to the Voltage waveform (phase shift). Also one/the other/both waveforms can be distorted relative to the other.

This is why the alternate unit of power VA is sometimes used instead of Watts to define power in AC systems. As VxA only truly equates to Watts in DC or purely resistive AC situations (with unity PF).

In an AC resistive load circuit Watts or VA completely equal each other.
In an AC reactive load circuit Watts does not equal VA, hence the need for the VA unit of power.

Dunno if this clears or muddies the waters further now 馃ゴ. Best I can do anyway.
Peter
 

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My media player box uses under 5W when playing 4K HDR HEVC video. I would certainly be concerned about a device using 7W to do nothing! :LOL:
 
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