Frequent Disconnections on GaN Chargers

I was working on my laptop today when my phone started to emit the charging chime, over and over again, every tens of seconds or so. There was no rhyme or reason to it. The C-to-Lightning cable was in good shape, the charger itself was firmly plugged into the wall, and yet the issue persisted even after I reseated all the connections a couple of times and checked the charging port to make sure there was no debris preventing a good connection.

The only likely culprit I could think of was the charger itself. I’d picked up this nice gallium nitride (GaN) charger in April this year, that could output 200 watts and could charge four of my devices at once. (Note: this is not a sponsored post or anything. I just linked what I bought because the product description page has the warning which I will show further down in this post.)

I initially assumed I’d gotten a dud, and was looking through my purchase history to see if I was within the exchange window, when something in the product description caught my eye.

(Translated from the Korean description:)

Warnings during use:
3. When using two or more ports, or when the charging output values fluctuate significantly, charging may temporarily stop and then resume to route power between devices.

That’s when it finally clicked: I had my phone and laptop connected to the same GaN charger. Opening up the power meter on my laptop, I could clearly see that the power was fluctuating based on the usage:


The GaN charger was stopping charging for a while based on the fluctuating needs of the laptop, which was causing my iPhone to stop charging and start charging again every couple of seconds. To test if this was truly the culprit, I unplugged my laptop and continued working. The problem didn’t come back.

The temporary solution?

Flip the mute switch, face down on desk. No more interruptions.

Note: this might not be a GaN charger specific issue. There may be chargers made with conventional tech that does the same thing that I may not know about. But I only first saw this disclaimer when purchasing GaN chargers, hence this blog post.