Li battery stuff + other
A few points.
1.
I don't like Apple because of policies like this. I have avoided the disease so far. Another for example is that in general they won't charge from 'any old' USB charger - that particular electricity is not Applie (Apply?) enough it seems. I agree that for many people they are the best choice though :-)
Until the very latest round of top end updates LG phones still seemed to have removable batteries.
However - Until quite recently I used a Samsung Galaxy S2 (it was say 5 years old or more) and it proved impossible to get a good quality replacement battery for it. Samsung haven't made batteries for it for years and the cheep and cheerful ones were not very cheerful. I finally replaced the phone when various apps became very slow or even failed to operate correctly - I assume because of insufficient RAM.
2.
Regarding 100% - 0% - 100% cycling.
I understand that Lithium Ion batteries are different from some other previously popular rechargeable battery technologies.
I am not an expert and can not make recommendations however I understand that L-I batteries can be degraded more rapidly by being deeply discharged OR by being stored at full charge. I have read that for example the Vauaxhall Ampera electric car (a European size family car) cycles the battery 80% - 20% - 80% in order to maximise battery life. This cannot be overridden by the user under any circumstances.
Ideally I suspect that many users who say use a device mainly at home would want the device connected to the charger at all times but not charged beyond say 80% charge. As far as I know no devices have this facility although I would be pleased to hear that I am misinformed.
Finally I understand that the quoted life of L-I batteries of say 1,000 cycles means 1,000 full discharge cycles and that partial discharge cycles are counted pro-rata. So 1,000 full discharge cycles would be equivalent to 2,000 50% cycles or 10,000 10% cycles.
At present I have a device that I use mainly at home that I bought used and have concerns about the battery condition. I often use a very long USB cable and a weak charger to try and keep the device floating at about 80%. I am considering making a cable with a variable resistance so that I can trim it more closely (this will require CAREFUL consideration of the power dissipation capacity of the resistor so unless you can carry out the necessary calculations - don't try this at home) or suppose I might make a full-on inline current limiting power supply. This is not commercially viable but it will amuse me:-)
3.
External Lithium Ion batteries that provide USB power sockets are available cheaply now. For many users an external battery will not be particularly inconvenient. Of course one that is Apple compatible may be more expensive.
4. iPhone and iPad experience only (via friends:-)
Applies to 'lightening' connector devices only, not the latest.
I understand that Apple detect 'their' chargers by having a simple potential divider across the power wires being applied to one of the data lines (or similar) by the charger so that the data lines have a steady x.x volts applied. The device then checks for this voltage before accepting the charge. It is technically easy to emulate this.
If any of the above is incorrect please fix it for me.