Should I remove the battery from an old phone before mining?

Usually, no—you should not remove an old phone’s battery just to mine on it. Most phones need the battery to start or run reliably, and opening a phone with a sealed battery can create a bigger safety risk than leaving it alone.

Check the battery before you do anything

The important question is whether your old battery is still safe, not whether removing it might make mining easier.

Do not charge or mine on the phone if you notice:

• A swollen battery, bulging back, or lifting screen.
• Leaking, an unusual chemical smell, or damage around the battery.
• Unexplained overheating, especially while idle or charging.

If you see these signs, stop using the phone. Turn it off and unplug it if you can do so safely. Do not press a lifted screen back down, puncture the battery, or try to flatten it.

Have a repair professional handle a damaged or swollen battery. Follow your local rules for battery recycling; do not put it in household rubbish. If the phone is smoking or hissing, keep away and contact emergency services.

Removable and sealed batteries are different

If your phone has a battery designed to come out by hand, check its manual before removing it. Switch the phone off and disconnect its charger first.

Even with an easily removable battery, the phone may refuse to work on charger power alone. Some models use the battery to help supply brief bursts of power. Removing it can cause restarts or shutdowns.

If the battery is sealed inside, do not pry the phone open just for mining. Glued-in lithium-ion batteries can catch fire if bent or punctured. A repair shop can assess or replace one, but that expense usually makes little sense solely to keep an old phone mining.

Do not improvise wiring, bridge battery contacts, or bypass temperature sensors. Battery-free operation is only worth considering if the manufacturer explicitly supports it.

Leaving it plugged in does not bypass the battery

A phone connected to a charger is not necessarily running directly from the wall. Its charging system controls how power reaches the phone and battery.

Some phones offer bypass charging, which powers the device while limiting or avoiding battery charging. Many older phones do not. A setting that stops charging at a chosen percentage is not necessarily true bypass charging.

Mining keeps the processor busy for long periods. That creates heat, and heat combined with a high charge level speeds up battery wear. Removing the battery would not eliminate heat from the processor or charging electronics.

If you still want to try mining

Only experiment if the battery is healthy and the phone works normally.

• Use a compatible, undamaged charger and cable.
• Keep the phone uncovered on a hard surface with airflow.
• Use the lowest mining intensity available.
• Stay nearby, and stop if it becomes unusually hot or shows a temperature warning.
• Avoid continuous or overnight mining.

Monero’s mining method, called RandomX, is designed to favor computer processors. An old phone—especially mining through a browser—is generally a poor earner. Battery wear, charging costs, and repairs can easily outweigh any return.

The bottom line

Keep a healthy battery installed unless your phone explicitly supports battery-free use. If the battery is damaged, stop using the phone rather than trying to turn it into a plugged-in miner. Removing a battery is not a general fix for mining heat or safety.