Least Battery Expensive Tether - Wifi or USB?

RumorConsumer

macrumors 6502a
Original poster
Jun 16, 2016
929
508
I just had this idea pop up

If you have a MBP and an iPhone there are two ways to tether - over USB or over Wifi. Oftentimes when Im tethering Im on the road as a passenger or in a vehicle of some kind.

Scenario A: Ive got the wifi on my Mac and my iPhone and Im tether to the Mac wirelessly and the Phone is handling its own power source - cigarette lighter or battery power. Mac isn't supplying any power to iPhone but it is powering its wifi chip.

Scenario B: Mac is connected via USB to the iPhone which is tethering over USB and unavoidably drawing current from the Mac over the same USB cable. Wifi chip is off on the Mac.

Which of these two scenarios will drain my Mac's battery fastest?
 

Gav2k

macrumors G3
Jul 24, 2009
9,217
1,606
I just had this idea pop up

If you have a MBP and an iPhone there are two ways to tether - over USB or over Wifi. Oftentimes when Im tethering Im on the road as a passenger or in a vehicle of some kind.

Scenario A: Ive got the wifi on my Mac and my iPhone and Im tether to the Mac wirelessly and the Phone is handling its own power source - cigarette lighter or battery power. Mac isn't supplying any power to iPhone but it is powering its wifi chip.

Scenario B: Mac is connected via USB to the iPhone which is tethering over USB and unavoidably drawing current from the Mac over the same USB cable. Wifi chip is off on the Mac.

Which of these two scenarios will drain my Mac's battery fastest?
Obviously B
 

2IS

macrumors 68030
Jan 9, 2011
2,937
433
I just had this idea pop up

If you have a MBP and an iPhone there are two ways to tether - over USB or over Wifi. Oftentimes when Im tethering Im on the road as a passenger or in a vehicle of some kind.

Scenario A: Ive got the wifi on my Mac and my iPhone and Im tether to the Mac wirelessly and the Phone is handling its own power source - cigarette lighter or battery power. Mac isn't supplying any power to iPhone but it is powering its wifi chip.

Scenario B: Mac is connected via USB to the iPhone which is tethering over USB and unavoidably drawing current from the Mac over the same USB cable. Wifi chip is off on the Mac.

Which of these two scenarios will drain my Mac's battery fastest?
B will drain it faster, but I have Scenario C for you.

Turn wifi off on the MacBook, keep the phone charging as with scenario A and use Bluetooth to hotspot to your phone. It will use slightly less power than wifi.
 

RumorConsumer

macrumors 6502a
Original poster
Jun 16, 2016
929
508
B will drain it faster, but I have Scenario C for you.

Turn wifi off on the MacBook, keep the phone charging as with scenario A and use Bluetooth to hotspot to your phone. It will use slightly less power than wifi.
What is the procedure to make sure bluetooth is whats being used?
 

2IS

macrumors 68030
Jan 9, 2011
2,937
433
What is the procedure to make sure bluetooth is whats being used?
You need to pair the MacBook to the phone. Once that is done, make sure wifi is off on the MacBook, then click on the Bluetooth icon (right next to the wifi icon) find your phone and connect.
 

KGB7

Suspended
Jun 15, 2017
925
749
Rockville, MD
Option D.
Get a power inverter for cigarette lighter to power the Mac.
Plug the iphone in to Mac via cable.
Both are being powered and charged for around $40 for 200w inverter.
 
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2IS

macrumors 68030
Jan 9, 2011
2,937
433
Option D.
Get a power inverter for cigarette lighter to power the Mac.
Plug the iphone in to Mac via cable.
Both are being powered and charged for around $40 for 200w inverter.
If going on a long road trip and you want to avoid battery anxiety, this is certainly the best option.
 

2IS

macrumors 68030
Jan 9, 2011
2,937
433
yeah might be headed in that direction. MacBook Pro AC adapters are rated 85W which is the most the computer would ever pull. Any reason to go 200w versus something like this - https://www.radioshack.com/products...5NrXLI2pCC7ZyQXpW2aAyROJOOTcVgHxoCX60QAvD_BwE
Most cheap inverters won't be able to output their rated capacity. While that one may end up working just fine, a 200watt inverter is what, an extra $10 or so? Seems it would be worth it to me just to have that extra headroom. I have a 200 watt inverter that craps out at about 150-160 watts of load.
 

KGB7

Suspended
Jun 15, 2017
925
749
Rockville, MD
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