Re:Why does iPhone 13 screen replacement disable Face ID
by aaronbeekay on Saturday October 02, 2021 @05:48PM
(#28732381)
Yes, it’s true that you can implement a pretty simple generic lithium-ion cell charging algorithm that will get the job done for most cells. But that’s not a “modern battery pack”. If you’re trying to eke hundreds or thousands of charge cycles out of cells, implement fast charging, do accurate state of charge estimation under load and in variable thermal conditions —- those things are very difficult to implement generically, and often do have parameters that depend on the specific chemistry being used. Modern devices have to do all of those things.
Yes, TI makes money when people use their battery management ICs with fancy cell monitoring, but I don’t see a lack of price pressure on those ICs. If manufacturers could implement the same features with a less complex, less expensive design, why would all of the modern battery systems, even in competitive sectors like consumer/retail electronics, integrate battery monitoring with the cells?
Re:Why does iPhone 13 screen replacement disable Face ID
by userbinator on Saturday October 02, 2021 @07:51PM
(#28733250)
We're talking about a single cell for a smartphone, not something like an EV battery pack.
Re:Why does iPhone 13 screen replacement disable Face ID
by aaronbeekay on Saturday October 02, 2021 @10:35PM
(#28734071)
Sure, maybe there’s less need for charge balancing in a smartphone battery, but the rest of the constraints still apply - fast charging is hard!
Re:Why does iPhone 13 screen replacement disable Face ID
by userbinator on Sunday October 03, 2021 @04:47PM
(#28740382)
Limiting the current to what the cell manufacturer specifies is not hard.
I don't think fast charging is a good idea anyway because it wears out cells faster, but that's another rant...
Lithium-ion cells are one of the easiest to charge - there's minimum and maximum voltages, and a maximum charge current. Simply limit charge current to the maximum until the cell reaches its maximum voltage, and then wait for the current to drop until it's nearly 0.
Of course, exceeding those limits at the upper end certainly can result in flames, but it's seriously not that hard to charge a cell. But people like to spew plenty of FUD about "complex algorithms" and the like, because the companies who make the ICs stand to profit from that.
Source: I have also worked in electronics on battery-powered devices.