Fuel

Fuel

A beacon draws from its own internal buffer, which it tops up from the fuel slot in the beacon's fuel tab.

One unit is about one second of one basic effect. That is the whole scale — the screen shows you running time rather than unit counts, because "4 hours 20 minutes" answers the question you actually have and "15 600 units" does not.

What burns

Item	Units	Roughly
Copper Ingot	150	2 minutes
Iron Ingot	300	5 minutes
Gold Ingot	900	15 minutes
Emerald	1 800	30 minutes
Diamond	3 600	1 hour
Netherite Ingot	28 800	8 hours

These are the figures the game shows you. It always rounds down to one unit — copper is 150 seconds and reads as "2 min" — so a beacon never promises more runtime than it has.

Those durations assume one basic effect kept to yourself. A level II effect shared with allies burns four times faster. See Effects for the arithmetic.

Copper is priced through the convention tag c:ingots/copper, so any mod whose copper follows the convention is accepted too, with no file per mod. Other items — and other tags — can be added by a datapack.

How refuelling works

The beacon consumes one item at a time, and only while it is actually short. It will not burn most of a netherite ingot to cover a three-unit gap.

It also refuses fuel its buffer cannot hold whole. A tier I beacon holds 1 200 units, so it cannot accept a netherite ingot at all — the ingot stays in the slot untouched rather than being swallowed for a fraction of its value. This is what gives the Capacity augment and the higher tiers a real purpose.

Beacon	Buffer	Holds
Portable Beacon I	1 200	20 minutes
Portable Beacon II	3 600	1 hour
Portable Beacon III / themed	10 800	3 hours
Portable Beacon IV	36 000	10 hours

A Capacity augment multiplies these by 2, 3 or 4.

Running dry

When the buffer empties, the beacon switches itself off, plays the beacon deactivation sound and says so in the action bar. It does not stop silently — effects ending with no explanation reads as a bug, not as a mechanic.

Because the beacon is now off, it will not drain again until you switch it back on.

Turning fuel off entirely

A server can set require_fuel = false, which makes beacons run forever once crafted.

This removes fuel from the game rather than leaving it inert: no fuel slot, no gauge, no runtime figures anywhere in the screen. A gauge that never moves and a slot that accepts nothing are worse than no gauge and no slot.