Can your modern i-phone do this?

[Connieblau]

October ”˜89 320i convertible 220,000 miles, one owner since November 1990 (mileage 8,000 miles). I have been successful over the past couple of years cleaning, tidying etc. new gaskets, radiator, and recently fixing a flicky temp gauge. Over the last Winter the battery has been disconnected for about 5 months.
I have taken out the dashboard cluster to clean and tighten the temperature gauge’s Earth connector and to check the two batteries that keep the car’s memory intact during such dead periods. Batteries are lovely and clean and intact and clearly printed with a manufacturing date of 89-03.
Is this unusual? Can your modern phone batteries do this?

[Speedtouch]

German quality for you. Some batteries will last for donkeys years perfectly intact (even though they may well be flat as a pancake), while others deteriorate very badly, with leaking and corrosion, etc., particularly cheap far-Eastern made zinc-carbon and watch/calculator batteries.

It certainly pays to keep an eye on them, and remove them from equipment if you intend on leaving it sitting for months.

[Steve]

Mine are 89-05 and still going strong.