I believe the research would suggest 80% doesn't really make an especially good target. Its mostly a linear relationship between state of charge and speed of battery aging, other than a step change around 50-70% depending on the chemistry.

source (one of many): https://iopscience.iop.org/article/10.1149/2.0411609jes/pdf

I keep my EV charged to just 50% most days for this reason, get below that step change.

Al Dente didn‘t really work for me. I used it constantly for 1.5-2 years (capped at 60-80) and my battery still went to 88% of design capacity. My iPhone‘s battery on the other hand has been tortured for three years (always charging 100%, fast charging, getting very hot in the sun) and is still at 85%.

I feel like the batteries nowadays are just made to last 2-3 years to get to 85-80% capacity no matter how you treat them

If you are on Android and have root, you can install ACC (https://f-droid.org/en/packages/mattecarra.accapp/). It lets you customise the charging profile of your phone as well as see battery statistics, but out of the box it

1. Caps charging to 80%

2. Pauses charging if it gets too hot, until it's below 40°C

If you sporadically need full capacity (travelling, etc), just hit the "charge once to 100%" button and you're good to go.

I had to bite my tongue seeing a young woman idly hoy one of those extremely wasteful ecigs in the bin on my way home earlier. I wa mentally working all the bits of complexity going to landfill.

Still, perhaps I should buy ex-landfill sites on the cheap, so my descendants can mine them.

> I can't believe that my iphone doesn't have a built-in setting to cap charging at 80%

They have a "smart charging" setting which is poorly defined. It says it limits charging to 80% sometimes using AI. I think the idea is it charges to 100% overnight, and 80% the rest of the time.

But i agree, it would be nice if it had a selector switch. Some laptops have a "aim for 60%, 80% or 100% battery charge" option.

You can get a gizmo called a Chargie that lets your phone control charge rate and max charge% over Bluetooth to this little interposer dongle that sits between the charger and phone. Getting enough to equip all my usual charge points would exceed the cost of a replacement battery, but I guess if they last for more than one phone it's possibly worthwhile.

I just got the batteries replaced in my iPhone X for about $45, and I was without the phone for less than an hour. I am amazed, and very happy not having to shell out $1000 for a new phone that would just have been a marginal upgrade to my current one.