Five tips to keep your devices’ batteries in tip-top shape

Never charge it when frozen. Left your laptop in the car overnight in winter? Let it thaw several hours before plugging it back in. (Same goes for power tools in the garage.)
Letting your battery stay drained for awhile can also ruin it. They also slowly lose charge while asleep. If you're not going to use your device for awhile, shut it down completely when the battery is between 50%–60%.
Staying at 100% is wear and tear on the battery. While it's OK to charge your phone overnight, it's better to unplug it after it goes past 90%. Put it in Airplane Mode overnight and you'll have a good charge to start the next day. Over time, this pattern will promote its longevity.
Batteries need exercise too. If you usually use your laptop plugged in at a desk, let it discharge to 20% or so, once or twice a week.
New batteries need a break-in period. Fully charge your new device, let it run down to 2–5%, charge it back up to 100%, and repeat once or twice. You'll likely increase its lifespan.