Purchasing 13” M4 MacBook Air - 35W or 70W Charger?

[sav_uk]

Hey All,

I’m currently about to purchase a new MacBook and finally retire my mid-2014 13” MBP which has served me well for the past 11 years.

I’ve been reading into whether I should go for the default 35W dual USB-C charger or opt for the 70W single USB-C charger instead. I’m seeing a lot of conflicting information about the 70W supposedly causing faster battery degradation due to heat.

However, I’ve also seen other information suggesting that the 70W charger allows for bypass charging (where the power source switches to AC when plugged in and the battery is fully charged) and that the 35W charger doesn’t allow this…

I’m really not sure what configuration to go with now. Opting for the 70W charger will add about a week onto shipping times, which I don’t mind.

Any help would be greatly appreciated!

 

[snipr125]

Absolutely get the 70w charger because it’s the only GaN charger (along with the 140w) that Apple offer.

Buy a secondary 35/45 watt multiport GaN charger from Ugreen/Anker for slower charging (and for your iphone/ipad etc) for around £20. Much better than the 35w silicon Apple charger for sure.

 

[sav_uk]

Absolutely get the 70w charger because it’s the only GaN charger (along with the 140w) that Apple offer.

Buy a secondary 35/45 watt multiport GaN charger from Ugreen/Anker for slower charging (and for your iphone/ipad etc) for around £20. Much better than the 35w silicon Apple charger for sure.

Thanks for your response. I was actually thinking of going for the 35W default adapter and then buying a 65W Anker adapter for fast charging.

I’m still curious as to whether or not the 35W charger allows the Mac to bypass the battery and draw power from mains when the battery is fully charged. I’ve seen lots of conflicting information so it would be great if anyone with a MBA and the 35W charger can chime in and confirm if the power source switches to the AC adapter when the battery is fully charged.

 

[russell_314]

if the power source switches to the AC adapter when the battery is fully charged.

I have the M2 air and it shows AC power when I plug in a 20 watt adapter. I don’t know if that’s its only source of power. How can I tell? The power level doesn’t go down.

 

[splifingate]

I selected the 70w charger with my recent purchase.

It's not supposed to be delivered until the 16th (or so), so I can't provide +/- on this.

I have something like 53 chargers in varying capabilities/ports, so having two ports on a Stock charger was not really a point of concern.

More to come...

 

[okkibs]

I was actually thinking of going for the 35W default adapter and then buying a 65W Anker adapter for fast charging.

I would do that as well because then you have 2 compact adapters and the dual port one is useful especially if you got an iPhone or something else to plug in and can make use of the 2 ports. The M4-Air will typically draw between 5-7W and 40W in most scenarios (when not charging the battery) so the 35W adapter is plenty for powering the Air.

The Air can draw more power when you want to charge the battery and use it at the same time, so instead of about 1.5 hours of charge time from a low charge to nearly full it will take more like 3 hours.

If you do want to charge the battery faster the more powerful Apple charger is useful but then since you have to pay extra for it you might as well buy a compact Anker Nano. In the end you should buy whichever adapter you have more use for. The 70W adapter can power pretty much anything though so check if you have other USB-C devices in your house that could use the higher wattage. It can actually power a USB-C soldering iron.

I’m still curious as to whether or not the 35W charger allows the Mac to bypass the battery

That's not a thing, the Mac will always use wall power when the battery isn't charging. The type of charger is irrelevant, any USB-C PD charger is enough. You can get a 20W iPad charger and that works. What actually happens is that the wall power gets used as long as the Air doesn't need more power than it can get from the charger. So if you run an intense workload and additionally put the display to max brightness then the power draw might exceed what a lower wattage charger can provide and then that small overhead will be drawn from the battery.

With the 70W adapter this will essentially never happen as the Air is limited by how hot the M4 chip can get without a cooling fan. With the 35W adapter it's unlikely to happen but it will slow down charge speeds as mentioned before.

 

[sav_uk]

I would do that as well because then you have 2 compact adapters and the dual port one is useful especially if you got an iPhone or something else to plug in and can make use of the 2 ports. The M4-Air will typically draw between 5-7W and 40W in most scenarios (when not charging the battery) so the 35W adapter is plenty for powering the Air.

The Air can draw more power when you want to charge the battery and use it at the same time, so instead of about 1.5 hours of charge time from a low charge to nearly full it will take more like 3 hours.

If you do want to charge the battery faster the more powerful Apple charger is useful but then since you have to pay extra for it you might as well buy a compact Anker Nano. In the end you should buy whichever adapter you have more use for. The 70W adapter can power pretty much anything though so check if you have other USB-C devices in your house that could use the higher wattage. It can actually power a USB-C soldering iron.


That's not a thing, the Mac will always use wall power when the battery isn't charging. The type of charger is irrelevant, any USB-C PD charger is enough. You can get a 20W iPad charger and that works. What actually happens is that the wall power gets used as long as the Air doesn't need more power than it can get from the charger. So if you run an intense workload and additionally put the display to max brightness then the power draw might exceed what a lower wattage charger can provide and then that small overhead will be drawn from the battery.

With the 70W adapter this will essentially never happen as the Air is limited by how hot the M4 chip can get without a cooling fan. With the 35W adapter it's unlikely to happen but it will slow down charge speeds as mentioned before.

This is so helpful! Thank you for such a detailed reply!

 

[Macbookey]

On my M2 I went with the default charger (30W). It absolutely uses wall power when fully charged regardless of the type of charger you are using. The contextual menu on the battery icon in the menu bar will clearly show this. The battery life is so phenomenal with  silicon that fast charging was not needed in my use cases. I went the less heat route and got the base charger. For those who need the fast charging, I don’t think sweating battery degradation is worth it. Get what you need. Batteries will all degrade and they are all replaceable. Enjoy actually using the device and let it work for you, as opposed to you always working for it.

 

[cucharared]

Having plenty of lower power chargers I went with the big hoss. It just seemed the correct choice in my case and the price was the same.

Ron

 

[GMShadow]

I use the standard 35W to charge my iPhone and MBA, but I only typically have to charge the MBA 1-2 times a week.

 

[ForkHandles]

My MacBook Pro is docked most of the time on a USB c lead attached to my screens. It be a rarity that I use the 96W wall charger I paid for.

 

[brgjoe]

My Macbook Air is pretty much plugged in all the time anyway. That way when I am playing a game (like currently BG3) on it I don't worry about the battery dying. And I got the 35W charger. It had no problem keeping up and so far no issues with it.

 

[adder7712]

I'm using the included 35W adapter.

Seems fast enough for me.

 

[Howard2k]

It's not a decision worth investing too much time in since third party GAN chargers are so cheap. Pick one, if it's a mistake, pick up another. The 70W will give you faster charging if you're the type of person whose use case means that you find yourself thinking "I wish it was charged faster". The 35W is better if you to charge multiple devices from one socket, particularly if traveling.