Confirmation of the toll that super-fast charging takes?

[B. Diddy]

This has been making the rounds: https://www.phonearena.com/news/OPPOs-40W-fast-charging-not-good-for-battery-longevity_id124509

(Bear in mind that this article is specifically about an Oppo phone with Super VOOC charging.)

 

[mustang7757]

Mostly the Chinese phones trying get higher charging speeds , Google , Apple, Samsung they just don't put faster charging without doing intensive testing.

 

[me just saying]

Mostly the Chinese phones trying get higher charging speeds , Google , Apple, Samsung they just don't put faster charging without doing intensive testing.

Especially after what happened with the note 7 Nobody wants another battery disaster, no matter the cause.

 

[mustang7757]

Especially after what happened with the note 7 Nobody wants another battery disaster, no matter the cause.

Exactly!

 

[Mooncatt]

And remember, just because a phone will accept higher estates doesn't mean you have to use them. Nothing wrong with using a list rated charger, and it'll help the battery last longer.

 

[Mike Dee]

So it's only a confirmation for a particular brand and not all Super fast charging.

 

[B. Diddy]

So it's only a confirmation for a particular brand and not all Super fast charging.

Yes, that's true. At this point, I'm not sure if it's related to superfast charging in general, or only to the Super VOOC technology itself. I edited the thread title to add a question mark.

 

[Mike Dee]

Yes, that's true. At this point, I'm not sure if it's related to superfast charging in general, or only to the Super VOOC technology itself. I edited the thread title to add a question mark.

Well when you have time to charge it's probably always best to do it slowly for a variety of reasons. When I'm Wireless charging overnight I can turn off fast charging on my device because I'll never need it quickly. Some people fear charging overnight at all.

 

[Mooncatt]

Yes, that's true. At this point, I'm not sure if it's related to superfast charging in general, or only to the Super VOOC technology itself. I edited the thread title to add a question mark.

I tried to dig in to this a while back, but details were a bit sketchy. What I think happens is all these various quick charging protocols only adjust voltage and amperage to the phone (with mitigations for heat build up), which the phone then transforms back into ~4.2-4.4V and its resultant amperage. Looking at battery monitor apps, the charging voltage to the battery itself is the same, regardless of what it's plugged in to, quick charging or not.

So my guess is that this article can apply to fast charging in general and not just Super VOOC. When looking at some of the Battery University articles, this makes sense, as they make note of the strict voltage tolerances for Li-ion batteries. Your charger may use a 10V connection through the USB cable, but putting 10V into a single cell Li-ion battery will let out the magic smoke... If not outright go boom. This video shows what happens when charging a battery just to 6V after removing the protection circuit. Don't worry, it's an iPhone battery, so nothing of value was lost.

https://youtu.be/dOyvLACUloA

 

[Mike Dee]

I tried to dig in to this a while back, but details were a bit sketchy. What I think happens is all these various quick charging protocols only adjust voltage and amperage to the phone (with mitigations for heat build up), which the phone then transforms back into ~4.2-4.4V and its resultant amperage. Looking at battery monitor apps, the charging voltage to the battery itself is the same, regardless of what it's plugged in to, quick charging or not.

So my guess is that this article can apply to fast charging in general and not just Super VOOC. When looking at some of the Battery University articles, this makes sense, as they make note of the strict voltage tolerances for Li-ion batteries. Your charger may use a 10V connection through the USB cable, but putting 10V into a single cell Li-ion battery will let out the magic smoke... If not outright go boom. This video shows what happens when charging a battery just to 6V after removing the protection circuit. Don't worry, it's an iPhone battery, so nothing of value was lost.

https://youtu.be/dOyvLACUloA

The amperage is what matters. Phones have protection circuits so I'm not clear on what the purpose of the demonstration is.

 

[Mooncatt]

The amperage is what matters. Phones have protection circuits so I'm not clear on what the purpose of the demonstration is.

Perhaps I wasn't clear enough. B. Diddy said he wasn't sure if that article is only applicable to that specific charging protocol, or if it applied to all. My point was that it can apply to all because I think those protocols only apply to power through the USB cable, and they all revert to the standard Li-ion voltage in the phone before being delivered to the battery. Voltage does matter, because a lower voltage necessarily means higher amperage when delivering the same wattage. Over voltage in an attempt to keep amperage down is dangerous.

For example, take a hypothetical 44W charger. It doesn't matter if it's Oppo's protocol, Samsung, Qualcomm, or any of the other proprietary protocols. That 44W will still be transformed from something like 10V 4.4A at the wall power supply into a 4.4V 10A input to the battery. And that's not getting into C ratings and current handling of the batteries.

I think the only way that article could apply specifically to Oppo's Super VOOC and no one else would be if they are feeding that high voltage straight into the battery. The video was evidence that doing so would be hazardous to say the least, disproving that idea.

 

[Mike Dee]

Perhaps I wasn't clear enough. B. Diddy said he wasn't sure if that article is only applicable to that specific charging protocol, or if it applied to all. My point was that it can apply to all because I think those protocols only apply to power through the USB cable, and they all revert to the standard Li-ion voltage in the phone before being delivered to the battery. Voltage does matter, because a lower voltage necessarily means higher amperage when delivering the same wattage. Over voltage in an attempt to keep amperage down is dangerous.

For example, take a hypothetical 44W charger. It doesn't matter if it's Oppo's protocol, Samsung, Qualcomm, or any of the other proprietary protocols. That 44W will still be transformed from something like 10V 4.4A at the wall power supply into a 4.4V 10A input to the battery. And that's not getting into C ratings and current handling of the batteries.

I think the only way that article could apply specifically to Oppo's Super VOOC and no one else would be if they are feeding that high voltage straight into the battery. The video was evidence that doing so would be hazardous to say the least, disproving that idea.

Can apply doesn't mean it does apply. The device controls what's coming into it and all fast charging is not the same. The video while entertaining is not relevant because the battery protection is by passed and it depicts a flaming battery while the link the OP posted is about battery degredation.

 

[Mooncatt]

Can apply doesn't mean it does apply. The device controls what's coming into it and all fast charging is not the same. The video while entertaining is not relevant because the battery protection is by passed and it depicts a flaming battery while the link the OP posted is about battery degredation.

I doubt the battery itself cares what protocol is used. All it cares about is that the voltage is right (and that is virtually the same across all Li-ion cells) and the current isn't overloading it. I couldn't care less about what is coming into the device; what matters is what goes into the battery itself.

We can carry this over to the flagships, like the Note 10+ with the 4,500 mAh battery. It can accept the 45W charger, which translates to roughly 10A into the battery. To make numbers a little easier, let's subtract 1A worth of overhead to account for heat loss and powering the phone itself, leaving us 9A into the battery. Regular Li-ion batteries are only safe for current equal to their rated capacity. 4,500mAh = 4.5A max charge current before causing accelerated wear. At 9A, it's putting double that current into the battery. To be able to accommodate such high charging, the battery would have to be designed physically larger to accommodate faster charging without added wear. I don't see that happening with phones and the trend to making them thin. Over current may not make it go boom, but it is added stress on it that leads to premature wear.

 

[Mike Dee]

I doubt the battery itself cares what protocol is used. All it cares about is that the voltage is right (and that is virtually the same across all Li-ion cells) and the current isn't overloading it. I couldn't care less about what is coming into the device; what matters is what goes into the battery itself.

We can carry this over to the flagships, like the Note 10+ with the 4,500 mAh battery. It can accept the 45W charger, which translates to roughly 10A into the battery. To make numbers a little easier, let's subtract 1A worth of overhead to account for heat loss and powering the phone itself, leaving us 9A into the battery. Regular Li-ion batteries are only safe for current equal to their rated capacity. 4,500mAh = 4.5A max charge current before causing accelerated wear. At 9A, it's putting double that current into the battery. To be able to accommodate such high charging, the battery would have to be designed physically larger to accommodate faster charging without added wear. I don't see that happening with phones and the trend to making them thin. Over current may not make it go boom, but it is added stress on it that leads to premature wear.

The Note 10+ is a bad example because it doesn't take full advantage of the 45W charger's capabilities. The total charge time is almost the same as with the 25W charger.

 

[Mooncatt]

The Note 10+ is a bad example because it doesn't take full advantage of the 45W charger's capabilities. The total charge time is almost the same as with the 25W charger.

It doesn't take full advantage of the 45W charger because it can't. If it did, then the battery would be toast in short order.

 

[Mike Dee]

It doesn't take full advantage of the 45W charger because it can't. If it did, then the battery would be toast in short order.

That's because the device ultimately controls the charge rate as I said from the beginning. It's only allows an initial faster bump for afew minutes if your phone is extremely low. The S20 Ultra which has a bigger battery super fast charges for a much longer period of time.