Proper phone charging

[vpr5703]

It's worth noting here that *ALL* Lithium-Ion charging methods slow down at 80%. Lithium based batteries charge in 2 phases called CC (Constant Current) and CV (Constant Voltage.)

In the first phase the charge controller supplies the battery with a constant amount of current and lets the voltage rise to the specified voltage. For most Lithium-Ion/Polymer batteries this will be about 4.2V/cell max voltage. Some can get up to 4.35V. At the end of this phase the battery is at max voltage, but is around 80% charged, although this can vary.

When the battery hits max voltage, the charge controller switches to CV mode, where it supplies a constant voltage and lets the current taper off until a specified charge current is reached, at which point the charge is terminated.

For systems where you can set the desired to charge to some % of max, what you are doing is altering the final charge voltage on the CC-CV switch.

 

[billt460]

I never leave a device plugged in after it hits 100% and always charge them in front of a desktop fan. If I need to charge in transit my phone is positioned in front of a vent with air on.

I have several devices, (power tools, dustbusters, portable vacuums, and other devices), where the charging deck automatically shuts off once the battery pack is fully charged.

In fact the instructions tell you to leave them attached until fully charged, and they will automatically shut off. You cannot overcharge them by leaving the battery attached to them. I'm assuming today's modern cell phones are no different.

 

[vpr5703]

I have several devices, (power tools, dustbusters, portable vacuums, and other devices), where the charging deck automatically shuts off once the battery pack is fully charged.

In fact the instructions tell you to leave them attached until fully charged, and they will automatically shut off. You cannot overcharge them by leaving the battery attached to them. I'm assuming today's modern cell phones are no different.

Correct. This has been the case for a VERY long time with Lithium batteries. A lot of knowledge is leftover bits and bobs from the NiCd/NiMH era, where chargers and batteries behaved differently.

 

[JHZR2]

The last few phones I've had will 'supercharge' until it hits in the 80s%, then is designed to slow down to the finish. Higher end phones no doubt have safety measures built in to minimize long term fast charging damage. Been charging every phone I've had to 100% for many years and have yet to have any sort of battery issue and most phones I have had for 3-4 yrs with moderate daily use. Have only upgraded over time for up-to-date software applications, that sort of thing. This subject reminds me of some buying a vehicle then afraid to drive it in less than perfect conditions. It's made to be driven!

What you’re describing isn’t unusual or unexpected. Lots of electronics have been able to vary their charge rate according to battery state of charge for a long time now. It doesn’t change the fact the batteries do have both Calendar life and cycle life challenges. You’re finding that you can use a device for a few years and not have a battery related issue is also not unexpected. I’m about to trade in a three-year-old iPhone 12 Pro, which is at 81% capacity. Notionally that’s fully usable, as a typical condemnation criteria for batteries is 20% capacity loss. Additionally, typical design for a battery is to have some excess capacity above the nameplate so that as it degrades in time some target operational capability is retained.

It’s really no different than saying that you had some car that is known to be unreliable, but that you yourself got 500,000 miles out of it. OK, that’s really great and I’m really glad to hear it, but it doesn’t mean at a whole that there aren’t fundamental challenges or concerns.

Most fundamentally, cycles, heat, and thyme, all have their effect on battery capacity losses.

 

[skyactiv]

Had a battery installed at an Apple Store on Sunday for my iPhone 12 mini. $89. Battery health was at 78%. They cracked my screen and had to replace it and it ended up taking over 2 hours. The old screen was just fine so it’s not like I gained something from it. Have had the phone since Black Friday 2020.

 

[y_p_w]

Had a battery installed at an Apple Store on Sunday for my iPhone 12 mini. $89. Battery health was at 78%. They cracked my screen and had to replace it and it ended up taking over 2 hours. The old screen was just fine so it’s not like I gained something from it. Have had the phone since Black Friday 2020.

That's one of the benefits of going with Apple. If they damage anything, they'll make it right. However, I've heard complaints from those who were told that they wouldn't do a battery service without paying for another repair since the front screen assembly was damaged.

It's possible for DIY battery replacement now - officially through Apple. But if the user damages anything, that's on the user.

There might be a slight advantage. A replacement front screen assembly will have a brand new fingerprint resistant coating.

 

[JHZR2]

I have several devices, (power tools, dustbusters, portable vacuums, and other devices), where the charging deck automatically shuts off once the battery pack is fully charged.

In fact the instructions tell you to leave them attached until fully charged, and they will automatically shut off. You cannot overcharge them by leaving the battery attached to them. I'm assuming today's modern cell phones are no different.

A power tool has a configuration of cells in it, with multiple in series and parallel to achieve the interface that is desired. The more cells you have, the more likely it is that some number of them will become slowly imbalanced, because the internal resistances, and, very slight differences between cells have an effect. I believe that some designs actually have a connection for the charger to balance them and read a thermistor. Believe my makita and DeWalt batteries do…

 

[JHZR2]

Had a battery installed at an Apple Store on Sunday for my iPhone 12 mini. $89. Battery health was at 78%. They cracked my screen and had to replace it and it ended up taking over 2 hours. The old screen was just fine so it’s not like I gained something from it. Have had the phone since Black Friday 2020.

I had my 12pro since the same timeframe I believe and it was at 81%. I’m a pretty heavy user.

My new 15pro I’m setting to stop charge at 80% unless I know I’m going to not be able to access a charger reliably. It will make it last longer. One of my kids will probably end up with this phone…