Phone gets hot and drains fast in the heat: what's normal and what isn't

In summer in Batumi we often hear one question: "my phone is hot and dead by midday, is it broken?". Sometimes yes, but usually not. Let's sort it out.

When heat is normal

• Charging, especially fast charging. The phone and adapter get warm.
• Games, navigation, video, the camera: the processor works at full power.
• The first hours after a system update: the phone re-indexes photos and data.
• Weak signal: in a basement, a lift or out of town, the phone transmits at full power.
• Sun and heat: in direct sun the body heats up by itself.

When it overheats, an iPhone shows a warning and limits what it does. That's protection, not a fault.

When heat is a warning sign

• The phone is hot at rest, without charging or apps running.
• It heats in one spot (for example near the cameras or at the bottom) and drains fast, even overnight.
• The heating started after a drop or water exposure.
• The battery drains in a couple of hours and the case or screen starts to lift, which could be swelling (see Swollen battery).
• The phone shuts down by itself at any percentage.

This can be a current leak on the board, a damaged battery or a system fault.

Why heat harms the battery

Lithium-ion batteries age fastest at high temperatures. One day on a car dashboard in the sun can eat a noticeable chunk of capacity. That's why phones in hot climates wear out their batteries faster.

How to protect your phone in summer

• Don't leave the phone in the sun: on the beach, on the dashboard, on a windowsill.
• Don't charge it in the heat under a pillow or in a thick case; take the case off while charging.
• Don't run navigation in the sun while charging if the phone gets very hot.
• Close unused apps that use location.
• If the phone overheats, don't put it in the fridge: the sudden change causes condensation inside. Just move it into the shade.

What to check yourself

• Settings → Battery: which apps use the most.
• Battery health: if capacity is low, the phone will heat up and drain more (see battery health at 80%).

If the phone is hot for no reason, don't wait: the technician will check whether it's the battery or the board (a phone inspection is free, and if board diagnostics are needed they cost 100 ₾, only if you decline the repair). Message us on Telegram.

Read also

• Phone fell in water: what to do in the first 10 minutes (and why not rice)
• Phone dropped in the sea: why salt water is worse than fresh water
• IP68 water resistance: can you swim with your phone?
• Cracked glass but the screen works: can you replace just the glass?