Battery life: how to make your devices last

In short

• Don’t charge above 80%
• Don’t discharge below 20%
• Charge slowly
• Turn on battery protection features where available

How much does it matter?

Manufacturers and tests agree: every charge and discharge wears the battery, especially above 80% and below 20%. Those are the ranges where cells are under the most stress.

Measurements over more than 4,000 cycles show much faster capacity loss when the full charge range is used (source). Keep it in perspective, though: a smartphone rarely exceeds 1,000 cycles in its life, and most batteries are designed for about 1,000. Only the start of that curve applies to typical use.

How to preserve the battery

Simply avoid excessive charging and discharging. Most modern devices include a feature that caps charging above a certain level. Its name and settings vary by manufacturer, but the goal is the same: avoid keeping the battery at 100% all the time.

Fast charging

Where possible, avoid fast charging: it stresses the battery more and produces more heat, both of which speed up wear.

Laptops

On a Lenovo laptop, for example, the Lenovo Vantage app lets you cap charging at a chosen threshold. If your laptop mostly sits on a dock, there is no reason to work the battery harder. A typical setting: charge to 80%, then let it drop to 75% before charging again. This buffer reduces long-term wear.

Smartphones

Samsung offers battery protection with three modes: Basic, Adaptive and Maximum. If you get through the day between 80% and 20%, or can recharge regularly, choose Maximum: it preserves the battery best (Samsung documentation).