Using <30W charger with MBP 16"/14" without discharge when browsing, streaming video, email ,etc.

[sam_dean]

This is for the purpose lengthening battery life by reducing wear and tear caused by fast charging

As Apple Silicon is so power efficient is it possible to use a charter that outputs

- 5W
- 10W
- 12W
- 18W
- 20W
- 29W
- 30W

Without discharge when using the notebook for browsing, streaming video, email ,etc.

96W & 140W would be needed when doing heavy work like video editing, playing games, 3D rendering, etc.

 

[russell_314]

I tested my MacBook Air with lower power chargers and it worked. I only did it as a test but use the 35 watt adapter it's designed for in actual use. I felt like this was a safe choice over the 67 watt power adapter that fast charged.

My worry is using low power charger might actually be worse for the battery. When using the proper charger it's basically not running off the battery but directly powering the computer. When you're using a phone charger or something like that perhaps the battery has to provide extra current in those brief moments when the charger can't keep up. It might not drop down a whole percent so you may not see it. I don't know this is just a theory and I don't have the test equipment to see if it actually is doing that.

 

[doboy]

I've used my 14" M1 Pro using a 20W charger for a while and didn't have any issues. I recently changed to a higher wattage charger because I'm using a hub that requires ~15W.

 

[poporange630]

Totally possible. My 14-Inch Macbook Pro is consuming roughly 5 Watt as I'm replying to this thread right now. It would be okay to use 20-30 Watt Charger, either the Apple ones or 3rd Party GaN Charger. The potential problem is that your charger will be working at high load and may over-stress or overheat if the design is not robust enough. My own choice is a 65 Watt GaN charger, but I've used a variety of 30-35W 3rd Party Chargers (Anker, Xiaomi, ZMI, etc) without issue.

 

[pshufd]

I've tested my M1 Pro MacBook Pro 16 with a 20 Watt charger while running YouTube and what happens is that the battery declines very slowly. This is with the volume set pretty high (I'm using it as a television) and screen pretty bright. I bought the Anker 2-port power brick a year ago to charge my iPhone and iPad and wish that I had waited for some of the better models (more power, more ports) to come out. I did this test at my mother's house where I left the OEM 140 watt brick at home - I would have enough power for the day without charging but I wanted to see if the little charger was usable. The idea on trips was that the 20 watt PSU would be able to charge the MacBook Pro overnight.

I would like something in-between. Ugreen has a 6 port adapter (4 USB-C + 2 USB-A) charger which looks interesting but it's priced much higher than other options. I think that it is more compact than the Apple brick. I'd guess that 30 watts gives you enough power and recharge capability for casual browsing though the charge rate might be pretty slow.

 

[FreakinEurekan]

I use a 30w charger pretty regularly without problems. Give it a shot!

 

[pshufd]

I used a 20 Watt charger this morning and it discharges very slowly with casual use. I have a 30 Watt charger (from M1 Air) on it right now and it's been at 90% for about 10 minutes. There is an indicator that it will be charged to full in 95 minutes but I'll see whether or not the charge level rises. I'm just doing casual stuff with a moderate task running in a Windows virtual machine.

I'm looking around for small GAN charging bricks, preferably with more than one port and I'd like to figure out what I can get away with on trips. The speed of the 140 Watt charger is really great but it's a chungus with only one port. It would be nice to have two USB-C and one USB-A so that I could also charge my phone and watch.

 

[pshufd]

It's definitely getting charged by the 30 Watt charger and at decent speed too. So 30 Watts for the M1 Pro MacBook Pro is enough. Then 15 for the iPhone and 5 for my watch so 50 Watts would be enough though I think that there are more around 60-65.

 

[tstafford]

This is for the purpose lengthening battery life by reducing wear and tear caused by fast charging

I wouldn't worry about this. Mac OS handles the battery and knows what it's doing.

 

[now i see it]

Being able to control peak charge level has come to iOS via shortcuts automation. On iOS you can now set the charger to turn off & on at any battery charge level you want. It works really well.

I recall Apple saying that they’re bringing the shortcuts app functionality to Mac OS. Hopefully the battery charge controlling automations will be included.