Same goes for an iPhone used for long CarPlay drives.
The combination of heat and staying at 100% for hours is not good for batteries.
Again - it’s just part of the battery chemistry we have to deal with.
Having options for those situations is a good thing.
If you don’t like the option don’t use it.
Agreed, including the fact I will probably rarely use it, but its existence has validity.
And for those that think longevity is just battery lottery - to a small extent there are variations, sure. But at the end it’s all chemistry. You won’t ever have a battery that will last 3x vs the average. Plus or minus a few percentage points, sure.
Assuming that was directed at me, I never said “just.” My evidence is personal experience but unlogged, so I will leave that out.
Furthermore, your collective source (
BU-808) has disclaimers that are more like flaws — not to discredit all of their testing. For example:
Figure 8 extrapolates the data from Figure 6 to expand the predicted cycle life of Li-ion by using an extrapolation program that assumes linear decay of battery capacity with progressive cycling. If this were true, then a Li-ion battery cycled within 75%–25% SoC (blue) would fade to 74% capacity after 14,000 cycles. If this battery were charged to 85% with same depth-of-discharge (green), the capacity would drop to 64% at 14,000 cycles, and with a 100% charge with same DoD (black), the capacity would drop to 48%. For unknown reasons, real-life expectancy tends to be lower than in simulated modeling.
So… Your model doesn’t work? More so, it shows that degradation is non-linear and much more difficult, if not impossible, to predict.
And immediately before the conclusion, “What Can Users Do?”:
The cycle count on DST (dynamic stress test) differs with battery type, charge time, loading protocol and operating temperature. Lab tests often get numbers that are not attainable in the field.
Again, very difficult to accurately measure and not (well) predictable.
I haven't seen proof that it extends the life of the battery significantly. I know my older batteried devices really don't show much difference either way. There's a lot of factors at play in that calculation.
Exactly. Of the factors:
Charge, discharge, current state of charge, and other variables are fairly well monitored and handled by the power management system, which includes communication with a — for perhaps lack of a better word — microcontroller embedded in the battery pack (what Battery University refers to as a “smart battery”). With occasional recalibration, there’s not much more the user must/should do.
On the other hand, temperature awareness is a necessary warning. Why? The device (e.g., iPhone) has limits controlling that factor. Indeed, the power management system can temporarily stop providing a charge when the battery pack/internal device
temperature exceeds a threshold or to prevent overcharging. However, for example, it’s mostly up to the user to ensure the device is not subjected to improper temperature. For example:
The interior of a car can get very hot, especially when parked in the sun. Experiments have shown that temperatures inside a closed vehicle can quickly exceed 125 °F (about 52 °C). Even on a cooler day, the temperature inside a vehicle can reach 100F in 25 minutes. The surfaces inside the car, such as steering wheels, dashboards and seat covers, can get even hotter than the air.
Source
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2,
3
Whether the system stops charging or is completely shut down/off, the device, including battery, will be exposed to a damagingly high temp.
