Doug asked: “With today’s devices having built-in batteries that you cannot replace, what is the best way to charge them so that you have maximum longevity for your device? Do you run them down to zero, and then charge them to 100%, or is it better to run it down to about 20% and then recharge it? And when you’re not using the device, is it okay just to leave it on the charger? I want to have maximum longevity for the devices that I pay so much money for.”
Doug, modern batteries mostly manage themselves for the most part, for example, they’ll do trickle charging when they get past a certain charge to protect it if you leave it plugged in, but there are a couple of tips that can help you.
Samsung makes a lot of batteries both for their own devices and for many others, and they have just a few of suggestions to maximize their lifespan.
In terms of charging, they claim that you do not have to discharge them fully like you would with other batteries and that, instead, you’re better off trying to keep them always at above 20%.
They also warn against exposing them to both extreme cold and extreme heat, since they can both damage the battery and shorten its life. That mostly translates into not letting your device sit in the sun, or leaving it inside a glove box in the summer or the winter. Apparently, there’s a myth about batteries lasting longer if they’re stored in the freezer, Samsung says that that is not correct and it can easily damage the battery.
If you happen to be storing your device for a while, they advise that you keep the battery at least 50% charged. Our guess is that leaving it at least 50% charged is a way of ensuring that as it slowly loses charge, it doesn’t go below 20%, but that’s only a guess.
As for leaving your devices plugged in when they’re charged, it should be ok. Just make sure they’re not under a pillow or anywhere that will not allow them to stay cool while charging, since that may shorten your battery’s life.
Even that is mainly a concern when the battery is not full, since that’s when it may heat up from charging. Batteries tend to stay pretty cool when they’re plugged in and fully charged.