macbook air faster charging

mlody

macrumors 65816
Original poster
Nov 11, 2012
1,055
687
Windy City
Does anyone know is Macbook Air would take the advantage of 60W or 85W chargers when charging? I believe the stock power brick is 45W so, would 85W cut the charging time in half (give or take)?
 

cruisin

macrumors 6502a
Apr 1, 2014
962
223
Canada
These chargers communicate to the computer, so the charger will only ever give the power the computer wants. This is also why people don't electrocute themselves on the exposed contacts, as the charger waits for a specific signal.

If there is a speed difference, it would only be a small one as the batteries cannot be charged quickly without overheating and causing damage. All batteries with fast charging are either kept in oil for cooling or come with custom chargers with higher voltages. Since the MacBook chargers already have high voltages for charging, there is not much improvement to be gained. The bigger MacBooks have bigger batteries, so the bigger charger is essentially spread out over a bigger area and therefore the batteries don't have problems from the extra power.

Only the 12 inch iPad has a big improvement from a new charger (12 watts to 29 watts), but it was designed to handle faster charging and the charger has a higher voltage. The regular charger cannot change this iPad while the iPad is in use, it will only keep the battery at the same level. Why they refuse to include the better charger and instead give you something barely adequate on something so expensive is a mystery.

The newer iPhones also has a small boost in charging if you use a iPad charger, mainly from the increased voltage.
 

mlody

macrumors 65816
Original poster
Nov 11, 2012
1,055
687
Windy City
These chargers communicate to the computer, so the charger will only ever give the power the computer wants. This is also why people don't electrocute themselves on the exposed contacts, as the charger waits for a specific signal.

If there is a speed difference, it would only be a small one as the batteries cannot be charged quickly without overheating and causing damage. All batteries with fast charging are either kept in oil for cooling or come with custom chargers with higher voltages. Since the MacBook chargers already have high voltages for charging, there is not much improvement to be gained. The bigger MacBooks have bigger batteries, so the bigger charger is essentially spread out over a bigger area and therefore the batteries don't have problems from the extra power.

Only the 12 inch iPad has a big improvement from a new charger (12 watts to 29 watts), but it was designed to handle faster charging and the charger has a higher voltage. The regular charger cannot change this iPad while the iPad is in use, it will only keep the battery at the same level. Why they refuse to include the better charger and instead give you something barely adequate on something so expensive is a mystery.

The newer iPhones also has a small boost in charging if you use a iPad charger, mainly from the increased voltage.
Thanks for taking time explaining this. I though that like iPhones, the Macbooks could take the advantage of bigger chargers, but I guess that they already operate at their limits.
 

kohlson

macrumors 68020
Apr 23, 2010
2,380
703
I haven't done a thorough analysis, but in our family we have 15-in MBPs and 13-in MBAs. One daughter insisted that her MBA charged faster with the large power supply, such that when her smaller (OE) supply broke, she wanted the larger one, since they cost the same. In any event, using the larger charger didn't seem to have any ill effect on her battery. It was good for over 1000 cycles before she got the warning to replace the battery, about 5+ years. Her 2011 MBA is still going strong. Anecdotal, but that's been our experience.
 

Macgyver1

macrumors member
Oct 18, 2016
69
32
These chargers communicate to the computer, so the charger will only ever give the power the computer wants. This is also why people don't electrocute themselves on the exposed contacts, as the charger waits for a specific signal.

If there is a speed difference, it would only be a small one as the batteries cannot be charged quickly without overheating and causing damage. All batteries with fast charging are either kept in oil for cooling or come with custom chargers with higher voltages. Since the MacBook chargers already have high voltages for charging, there is not much improvement to be gained. The bigger MacBooks have bigger batteries, so the bigger charger is essentially spread out over a bigger area and therefore the batteries don't have problems from the extra power.

Only the 12 inch iPad has a big improvement from a new charger (12 watts to 29 watts), but it was designed to handle faster charging and the charger has a higher voltage. The regular charger cannot change this iPad while the iPad is in use, it will only keep the battery at the same level. Why they refuse to include the better charger and instead give you something barely adequate on something so expensive is a mystery.

The newer iPhones also has a small boost in charging if you use a iPad charger, mainly from the increased voltage.
Well said, just to add; charging at higher wattage than factory will negatively(pun intended) effect battery longevity.

Best
 

cruisin

macrumors 6502a
Apr 1, 2014
962
223
Canada
Well said, just to add; charging at higher wattage than factory will negatively(pun intended) effect battery longevity.

Best
Except they don't, as the computer asks for a specific amount of power which the charger provides.

You can use a compatible higher wattage adapter without issue, but it won't make your computer charge faster or operate differently.
https://support.apple.com/en-ca/HT201700
 
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