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Comment by endisneigh | Hacker News Reader

Next thing Apple needs to do is setup MagSafe batteries to act as the primary battery for iPhones.

Right now using a magsafe battery charges the built in battery which is then drained by iPhone usage. Ideally what would happen instead is iPhone usage would use the magsafe battery first, then the built in battery.

The result of this is that magsafe batteries effectively are equivalent as replaceable ones.

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I don't think the current setup is notably different from what you're proposing.

The phone does use the MagSafe battery first, it just uses it through the internal battery, but that is just a matter of semantics. It shouldn't have a notable impact on battery health.

> It shouldn't have a notable impact on battery health.

Is that actually true? Lithium batteries seem kind of fussy.

Batteries don't like staying at 0% or 100%. They don't like extreme temperatures. And lastly, they don't like cycles.

I'm not entirely sure how the internal power routing works, but my understanding is that it's not adding cycles to your battery if you're using the power as it's being added, even if it's going through the battery.

You'll likely see more degradation from the wireless charging waste heat effecting the battery.

Why wouldn't it?

The critical importance here is if you plan on keeping your phone for a long time, a degraded internal battery is fundamentally the limit under the current scheme.

Or to put it another way, imagine you had a battery that only lasted a single minute, and a magsafe battery that lasts a full day. How long is your phone going to last? What will happen is that both your internal battery and magsafe will be drained, with the magsafe being drained the most. Eventually your internal battery will die, and so will your phone.

The other issue with using the internal battery (pass through, or charge) is that you're wearing it down more.

Maybe the behavior is different in an iPhone 14?

Li-ion battery degradation is minimal, or even negligible when they aren't cycled across different capacity ranges AFAIK. What that means is that current charging the battery while it is getting discharged at a similar rate (which usually means a constant battert voltage) doesn't induce wear in the same way as charging the battery from a capacity of 10% to 100% (or even from 75% to 80%) does.

But that could be different when that constant charge/discharge is happening at high capacity levels, lithium-ion batteries are weirder when they are at their maximim voltage. My knowledge is rusty at this point so let me know if I got any of this wrong.

But doesn't using one battery through another effectively mean that you're using both batteries in terms of wear and tear? If the phone drains the internal battery and the magsafe battery is charging the internal battery, to me that sounds like both batteries are in use experiencing normal wear. If that's not how it works, I'd be curious to hear how it does work.

MagSafe wastes energy due to its inefficiency. It’s hard to believe Apple’s eco-friendly aspirations when they introduce such features.

People want wireless charging, that isn't changing. MagSafe is a more efficient version of that compared to basic Qi charging like every other device offers because the magnets ensure perfect alignment.

People want a lot of things. I doubt that Apple would have lost significant market share for not providing wireless charging.

My thought here is that the same people complaining about wireless charging efficiency would be the ones complaining if Apple didn't offer it.

Can't win.

They offer a more efficient version of a feature everyone wants. Complain that everyone else is doing it worse.

If they “can’t win” anyway, they might as well have chosen the more environmentally-friendly option. The criticism is that they didn’t.

I disagree. There is always something to criticize, and some people will always want to do it. Might as well have a nice feature.

The point isn’t about avoiding criticism. The point is that Apple proclaims that they care about eco-friendliness and then introduces features that are the opposite. “Might as well have a nice feature” translates to “might as well be eco-unfriendly”.

Your arguments natural progression results in 'why make anything, it is not eco-friendly', which is silly.

Compromises are always made, and there are way bigger fish to fry. To me it seems like criticism just to criticize.

The energy used to power your phone is completely trivial. Just one trip in your car would use more than your lifetime phone usage.

The internal battery is replaceable though. The store will put a new one in for less than the cost of one of those MagSafe batteries.

I’m confused. Isn’t that what happens? Some portion goes to operating the phone and the rest to charging the battery? How does it work differently?

It doesn’t hook into the same charging system the phone uses for normal? Is that special for MagSafe? I don’t really understand how it’s different and can’t find anything online to read more about this.

To my knowledge if you had a dead battery, and used magsafe you still wouldn't be able to use your phone.

Correct, just like with a power cable. The phone needs to have some charge for basic operational safety. e.g. what happens if the user suddenly unplugs. Or are you saying MagSafe can't charge a dead phone?

This would be cool.

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