I did not explicitly specify in my post “Quickpost: Standby Power Consumption Of My USB Chargers” that I did my tests here in Flanders, Belgium and thus that the mains electricity is 230V 50Hz.
I wondered what the results would be in other parts of the world, like the USA. To answer this question, I redid my tests with the USB chargers powered by an AC power supply that delivers electricity at 120V and 60Hz.
The devices I tested are:
- Apple A1357
- Apple A2347
- Anker A2053
The no-brand USB charger was not tested, as the input specs specify 220V – 240V.
I connected each one to the AC power supply (120V 60Hz) and used a powermeter (GPM 8310, resolution 0,1 µW) to measure the standby power consumption over 24 hours.
This is the result:
| Model | 24 hours (Wh) | 1 hour (Wh) | 1 year (Wh) |
| Apple A1357 | 2,0425 | 0,0851 | 745,5125 |
| Apple A2347 | 0,5473 | 0,0228 | 199,7718 |
| Anker A2053 | 3,7527 | 0,1564 | 1369,7360 |
24 hours is the measured data, the “1 hour” and “1 year” columns are calculated based on the 24 hours data.
And here is the summary for 120V and 230V:
| Model | 1 hour (Wh, 120V 60Hz) | 1 hour (Wh, 230V 50Hz) |
| Apple A1357 | 0,0851 | 0,1202 |
| Apple A2347 | 0,0228 | 0,0530 |
| Anker A2053 | 0,1564 | 0,2114 |
It’s clear that my USB chargers consume less standby power at 120V 60Hz than at 230V 50Hz.
Quickpost info
Didier Stevens 
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