Cold temperatures slow the chemical processes that move lithium ions through a phone’s battery. The battery’s internal resistance rises and its voltage can sag under load, so the phone may show less charge or shut down sooner. In many cases the effect is temporary: performance improves as the battery returns to its normal operating temperature. Avoid charging a very cold device until it has warmed safely.
A battery is a chemical system
A lithium-ion battery stores and releases energy through electrochemical reactions. Lower temperatures slow ion movement and make it harder for the battery to deliver current quickly. A phone running a bright screen, camera or wireless connection may demand more power than a cold battery can comfortably provide.
Why the percentage can change
When voltage drops under load, the phone’s battery-management system may estimate less usable energy or shut down to protect the device. As the battery warms, voltage and available performance can recover; the charge indicator may rise again. Apple notes that cold can temporarily reduce battery life and that performance returns when the device’s temperature returns to its normal range. [1]
Cold-weather behaviour depends on battery age, temperature, workload and device design. A sudden shutdown in the cold does not necessarily mean the battery has permanently lost that amount of capacity.
Warm it gradually and charge safely
Keep the phone close to your body or in an insulated pocket when outdoors. If it becomes very cold, let it return gradually to its operating range before charging. Avoid placing it on a heater or using intense direct heat; rapid heating can be unsafe and may cause condensation.
Cold and heat affect batteries differently. The temporary loss of performance in cold conditions is not the same as long-term battery ageing, which gradually reduces capacity over time.
Sources and evidence
- Apple Support — If your iPhone or iPad gets too hot or too cold ↗
Operating temperatures and temporary battery-life changes in cold.
- Apple Support — Charge and maintain your iPhone battery ↗
Cold-related temporary performance reductions and battery guidance.
- Washington University — A clear view to better batteries ↗
Cold charging can contribute to lithium plating and long-term battery risk.
Sources consulted: 11 October 2026. Written with AI assistance and checked against the linked references; not independently reviewed by a subject specialist. Sources do not endorse this article. See our editorial policy.
Revision: Original explanatory article prepared from linked scientific and institutional sources; scope and uncertainty are stated in the text.