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How does the iPhone know the battery has been replaced? Cycle counter? If the cycle counter is stored on the battery then fine but if stored on the phone then i

by xt00 9y ago

How does the iPhone know the battery has been replaced? Cycle counter? If the cycle counter is stored on the battery then fine but if stored on the phone then it seems like replacing the battery might not solve the problem..

mankash666 9y ago
It's simple voltage/current measurements. An iPhone 6s might start off with an effective capacity of 1800mah, that reduces to, say 1250mah in 2 years. If your iPhone requires 1350mah for peak performance, you're out of luck
- xt00 9y ago
  Yea I’ve used a variety of battery charging circuits in designs I’ve done and measuring voltage and current are pretty easy but measuring capacity is not obvious instantaneously — you have to store a history of how voltage changed while charging or discharging. And sometimes you don’t get a full discharge or recharge and the person may use the phone while charging. As a result you have to save a history of multiple cycles to try to average and account for various situations like that. So the result is that you have some driver that saves a value or set of values someplace. And replacing the battery I would assume would not reset this unless there was some Id or value stored in the battery in an eeprom. So my assumption would be that simply replacing the battery may not immediately fix the problem, you may have to totally discharge and recharge your phone multiple times to essentially reset the low pass filtered history of your battery charge discharge cycles. So I guess my question would be if somebody tested if after replacing the battery they instantly had higher performance or not..
mrmondo 9y ago
As someone else stated it is the measurement of the totally battery capacity, NOT the number of cycles. While I don’t want to defend anyone here this is not planned obsolesce, it is a mitigation strategy to prolong the general use of a device as it degrades. However yes, Apple probably should have given a notification to users of degrading / worn batteries of their state and that performance may be affected.

by xt00 9y ago

mankash666 9y ago

It's simple voltage/current measurements. An iPhone 6s might start off with an effective capacity of 1800mah, that reduces to, say 1250mah in 2 years. If your iPhone requires 1350mah for peak performance, you're out of luck

xt00 9y ago
Yea I’ve used a variety of battery charging circuits in designs I’ve done and measuring voltage and current are pretty easy but measuring capacity is not obvious instantaneously — you have to store a history of how voltage changed while charging or discharging. And sometimes you don’t get a full discharge or recharge and the person may use the phone while charging. As a result you have to save a history of multiple cycles to try to average and account for various situations like that. So the result is that you have some driver that saves a value or set of values someplace. And replacing the battery I would assume would not reset this unless there was some Id or value stored in the battery in an eeprom. So my assumption would be that simply replacing the battery may not immediately fix the problem, you may have to totally discharge and recharge your phone multiple times to essentially reset the low pass filtered history of your battery charge discharge cycles. So I guess my question would be if somebody tested if after replacing the battery they instantly had higher performance or not..

mrmondo 9y ago

As someone else stated it is the measurement of the totally battery capacity, NOT the number of cycles. While I don’t want to defend anyone here this is not planned obsolesce, it is a mitigation strategy to prolong the general use of a device as it degrades. However yes, Apple probably should have given a notification to users of degrading / worn batteries of their state and that performance may be affected.