Is it bad to charge a phone in the cold?
The phone has been in a freezing car all night or died on a winter walk, and the obvious move is to plug it straight in. It's worth waiting a little first.
Why charging in the cold is the problem, not using
When you charge a lithium-ion battery, lithium ions travel to the negative side and tuck themselves in between layers of carbon (graphite). In the cold that tucking-in slows right down. If the charger keeps pushing at normal speed, ions pile up faster than they can fit and some turn into a thin film of lithium metal on the surface instead. This lithium plating:
- permanently removes lithium that could have stored charge, so the battery holds less from then on;
- can grow into tiny needle-like crystals, which in severe cases can damage the separator inside the battery.
Using a battery in the cold works the other way round: ions are leaving the graphite, not squeezing in. It's slower and the phone may shut down early (see why phones die in the cold), but it doesn't cause plating.
Wirebook's cold battery lesson shows the ions slowing down as you lower the temperature, and why the pretend tablet refuses to charge below 0 °C.
Your phone already tries to protect itself
Phones, tablets and laptops have a battery management chip that watches the battery temperature. Typical behaviour (exact limits vary by maker and model):
| Battery temperature | What a well-designed device does |
|---|---|
| Below about 0 °C (32 °F) | Stops charging, or trickles very slowly |
| About 0-10 °C (32-50 °F) | Charges at reduced speed |
| Room temperature | Charges normally, including fast charging |
| Hot (in the sun, under a pillow, in a hot car) | Slows or pauses charging until it cools |
So if a cold phone shows "charging on hold", "charging paused" or charges very slowly, that's the protection working. It isn't a broken charger. Bring the phone somewhere warmer and it will resume.
The battery itself warms more slowly than the air around it. A phone that has been in a freezing car overnight can take a while to warm through even after you've gone indoors.
How to charge safely after the cold
- Bring it inside and wait. Leave it in a pocket or a bag, or on a table at room temperature, until it no longer feels cold to the touch. From properly cold, 30-60 minutes is a sensible wait.
- Don't speed it up with heat. No radiators, hair dryers or heater vents.
- Check for condensation. A cold phone taken into a warm, humid room can mist up. Warming slowly in a bag helps. If the phone warns about moisture in the charging port, unplug it and let it dry before charging.
- Then charge normally.
Charging in a cold car
On a winter drive, a phone on a car charger usually starts cold. Most phones handle this by charging slowly until the car and phone warm up, which is fine. If the car is still freezing and you don't need the phone right away, it's kinder to wait until the heating has warmed the cabin. Don't leave phones charging in a parked car overnight in a frost.
Power banks, laptops and other batteries
- Power banks are lithium-ion too (how many charges yours really gives). Cheaper ones may not block charging when cold, so charge them indoors at room temperature. Using a cold power bank to top up your phone is fine, though it will deliver less.
- Laptops, earbuds, smartwatches and cameras follow the same rule: use in the cold is OK, charge once warm.
- Electric cars have heaters and controllers that warm the pack before fast charging; that's why winter charging can be slower and why pre-conditioning the battery before a charging stop helps.
Related
Phone dies in the cold at 30% · Battery percentage jumps or drops suddenly · Phone gets hot while charging · Power bank won't charge my phone · Battery health %: when to replace · Phone battery drains overnight · Interactive: chill a pretend tablet and watch it switch off
Questions
Is it bad to charge my phone when it's cold?
Yes, if the battery is below freezing. Charging a lithium-ion battery below about 0 degrees C (32 degrees F) can cause lithium plating, which permanently reduces capacity. Let the phone warm to room temperature first.
Why won't my phone charge in the cold?
Its battery management chip pauses or slows charging when the battery is too cold, to avoid damage. Bring it somewhere warmer and charging will resume.
How long should I wait before charging a cold phone?
Until it no longer feels cold to the touch. From properly cold, 30 to 60 minutes at room temperature is a sensible wait. Don't speed it up with a heater.
Is it OK to charge my phone in a cold car?
Usually yes once the car is warming up, because phones charge slowly while cold to protect the battery. Avoid leaving a phone charging in a parked car overnight in freezing weather.
Is using a phone in the cold bad for the battery?
Not lastingly. It shortens runtime and can cause early shutdowns, but the charge returns once the phone warms. Charging below freezing and heat are what cause lasting damage.
Published .