A mobile hotspot drains your battery quickly because it keeps both the Wi-Fi and cellular radios working hard at the same time. Your phone broadcasts a Wi-Fi network for other devices while pulling data over the mobile network and passing it along, all continuously. Heavy use, more connected devices and a weak signal make the drain worse, and the phone often warms up too.
Why this happens
- Sharing your connection turns on the Wi-Fi radio in broadcast mode, which uses more power than joining a network normally.
- At the same time the cellular radio is busy sending and receiving all the shared data, and transmitting uses a lot of power.
- The radios stay fully awake rather than idling to save power, so drain is constant while the hotspot is on.
- A weak signal forces the phone to transmit at higher power to stay connected, which drains faster.
- More connected devices and heavier use, like video or downloads, mean more constant work and more heat.
Is this normal?
Yes. Fast battery drain while running a hotspot is completely normal, because the phone is doing the job of a small router on top of its own tasks.
Does it cause any problems?
Besides quick battery drain, the phone can get warm, and heavy sustained use may trigger thermal throttling that slows it down. It also uses your mobile data allowance quickly. None of this harms the phone if you let it cool.
How to fix or check it
- Keep the phone plugged into a charger while using it as a hotspot for long periods.
- Turn the hotspot off as soon as you finish, since it keeps the radios awake even when idle.
- Lower the screen brightness or let the screen turn off, as the hotspot keeps working with the display off.
- Connect fewer devices and avoid heavy downloads or video over the hotspot when on battery.
- Use it where the signal is strong, because a weak signal makes the phone work and drain harder.
- On both iPhone and Android, set the hotspot to turn off automatically when no devices are connected, if that option is offered.
Frequently asked questions
How much battery does a hotspot use?
It varies, but a hotspot can drain a phone in a couple of hours of steady use, much faster than normal, because two radios run at full power together.
Is using a hotspot bad for my phone battery?
Occasional use is fine. The main effects are fast drain and some heat. Keeping the phone cool and charged during long sessions protects the battery over time.
Why does my phone get hot as a hotspot?
Because the radios and processor work hard and constantly, generating heat. Keep the phone out of direct sun and off soft surfaces so it can cool.