Hello Lawrence.
to keep my post short I avoided TMI. I’ll now expand on my original post.
If a Lithium-Ion battery is charged to 100% and then either not used immediately or lightly used so the charge state stays above say 90% for some time, the battery will prematurely age and it’s health will drop.
Apple acknowledges this here;
Batteries - Maximising Performance - Apple (UK)
see this statement;
Do not fully charge or fully discharge your device’s battery — charge it to around 50%. If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life.
This statement relates to storing a phone however in my opinion it is a disingenuous statement which only eludes to the truth. 100% is 100% and how long is storage for ‘some time’? If 10 days does some damage the surely so does 10 hours or even 10 minutes, obviously to a lesser extent but the cumulative effect will be similar.
A brief Google search will show many commentators who advise against 100% charging.
Perhaps it’s in a phone manufacturers interest to avoid the full truth in the interest of sales and replacements.
I’m an electronic engineer in Industrial Automation and Control where battery back-up systems (DC-UPS) utilising Li-Ion are commonly used.
I’ve also driven Tesla’s since 2016, my house is powered by Tesla Powerwalls and my wife drives another EV.
I have a huge investment in Li-Ion and consequently need to understand them.
I have made a study of maximising battery life and have investigated the chemistry and chemical reactions in Li-Ion batteries.
If you have been charging consistently to 100% I’m amazed that your battery health is still so high, perhaps the exception that proves the rule.
Thank you for your advice but I’d rather follow my experience.
Regards
Malcolm.