Hacker News Reader

Comment by Temporary_31337 | Hacker News Reader

[flagged]

That is not the case. Fast charging is worse for the battery, but a 60W GaN vs a 60W SiC charger is not going to treat your battery any different, for example.

The concern about chargers being 'good' or 'bad' for your battery is mostly an issue with 90s and 00s technologies where chargers directly interfaced with batteries. The way modern PD devices work, however the battery charges is entirely up to the onboard charge controller in your device. They always charge in accordance with how your device was designed to charge. We call them 'chargers' but really they're just power supplies.

GaN is just the transistor technology, how does that translate to bad for batteries?

It's not the GaN, it's the higher wattage that's possible. Fast charging can increase device/battery temperature which, for fan-less designs like iPhones or MacBook Air, can lead to slightly higher degradation.

That's not correct and very misleading. The wattage is the max amount of power the charger can output. It's up to the device being charged to negotiate and pull the right amount of current and wattage. This is case with modern charging protocols and even older 5v usb chargers. This is similar to how you might have a 15A rated outlet in your house, but that doesn't mean it's going to "force" 15A though whatever device you plug into that. It's the device that determines how much power it will pull.

My analogy is an EV - of course your EV isn't going to pull current that's dangerous but fast charging it has been shown to degrade battery life - especially if the EV doesn't have active cooling for the battery pack.

Putting that EV on a slow charge that might be sufficient for an overnight charge might be better for the battery pack.

This is a setting on the device side. The EV it self will decide how much current to pull, based on charging profile that you set.

You are correct on that charging at higher currents can reduce battery cycle life, but it's the device it self that decides how much current to pull based on the charging profile that you selected. In your example with an EV,you set the charging profile on your vehicle, not the outside charger. The charger's job is to provide as much current/voltage as requested by the device.

You are correct, but the comment didn't say "fast chargers," it said GaN.

Here is a (very cute) 35W GaN charger. This would be considered fast charging for a phone, but not for a laptop. https://sharge.com/products/shargeek-retro-35-gan-charger

It is just plain inaccurate to state that GaN is the problem, or opens up new possibilities for fast charging. All it does is make the charger smaller.

For the uninitiated, can you explain like I’m five? Why are GaN chargers worse?

What makes them not as nice for your battery?

I’d love to know why GaN is bad.

As far as I understand electronics between the AC electricity and DC device make more of a difference

I believe this is misinformation and probably should be flagged.

Reply on news.ycombinator.com