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Ask HN: On-Demand Phone Charger
When you have 6 phone chargers around the house, napkin-math is showing me $22.00/month in electric bill.
Not to nitpick, but surely there is a charger out there in the marketplace that can apply electrical load once the iPhone/Android gets connected to the charger. That is assuming that Energy Saving Trust accurately assert that it is eating electric cost wether the device is connected or not. [1]
Perhaps with a big zenier diode or something instead of an always-on wounded transformer coil sucking electricity …
Is there such a thing? I could imagine some type of mechanical (or even electronic) relay to kick in that coiled transformer load but as a tiny consumer product?
Does one exist? If so, how would one search for such a product on search engines?
Napkin Math:
35W/hour (rated phone charger)
24 hours x 365 days (always on)
306.6kW/year, total usage (1 charger)
$0.149/kWh electric rate
$45.68 per charger
or $274.10 annual electric bill for six(6j chargers
of course, Energy Saving Trust claims the chargers are essentially always on, whether you have the device connected or not.
[1] http://monopolybuysellrent.co.uk/advice/energy-saving-tips/
- detaro 4y agowhat's your napkin math? because switching PSUs if well-done are pretty darn efficient even if idle (and the most efficient topology overall)
- egberts1 4y ago35W/hour (rated phone charger) 24 hours x 365 days (always on) 306.6kW/year, total usage (1 charger) $0.149/kWh electric rate $45.68 per charger or $274.10 annual electric bill for six(6j chargers of course, Energy Saving Trust claims the chargers are essentially always on, whether you have the device connected or not. updated OP.
- detaro 4y agono phone charger is going to use the rated power if nothing is connected, I'd expect more like something in the range of 0.2-2W
- BOOSTERHIDROGEN 4y agoNewest Apple 35W Dual Charger “no-load power consumption of the charger at 220V 50Hz is 0.063W”[1] [1] https://www.chongdiantou.com/archives/157270.html https://www.chongdiantou.com/archives/157270.html
- gus_massa 4y agoNote that a cell phone charger use 5-10W when the cell phone is charging, but it uses only 0.1W or less when the cell phone is not connected. I can't get official numbers, but this article has some info https://www.howtogeek.com/231886/tested-should-you-unplug-chargers-when-youre-not-using-them/ https://www.howtogeek.com/231886/tested-should-you-unplug-ch...