Charging & battery

The Metal and Ultra are battery-powered and charge over USB-C.

Use

• ✓ USB-C, 5 V, 1 A charger
• ✓ An undamaged USB-C cable

Don't use

• ✕ Fast chargers above 5 V: they can damage the feeder
• ✕ A damaged USB-C cable

Charging

1. 1 Plug in USB-C 5 V, 1 A charger
2. 2 LED shows charging Slow glow (v2.2.7 and the betas), or a double blink every 3 s (older firmware)
3. 3 About 3 hours First charge too. On v2.2.7 (Wave 3 and newer) the LED goes off when full.
4. 4 Unplug to grind The feeder is made to run on battery

Before grinding, disconnect the USB-C cable - the feeder is designed to run on battery, not while plugged in.

No LED while charging? That’s usually normal

The charging double-blink only shows while the device is awake. After about 3 minutes the feeder goes to sleep and the LED turns off - charging continues in the background. Press the power button to wake it and see the charging pattern again. A fully-charged device also stops blinking. So a dark LED with the cable plugged in almost never means a defect.

Feeder stalling on every setting? Charge it first

A low battery can cause constant stalling on all speed settings - without showing any low-battery warning. Before troubleshooting a stalling feeder, charge it fully (or test with the USB-C cable connected). If the stalling stops, it was the battery.

Firmware v2.2: charging behaviour

On firmware v2.2 (Metal Wave 3 & newer, Ultra, Pro V2), plugging in the cable stops the motor and the feeder waits in charging mode. It never starts by itself on the charger; press the button if you want to run it while plugged in. Plugging in also wakes a sleeping feeder and it stays awake while charging, so the charging pattern stays visible. Get v2.2 on the Firmware page.

Runtime

Battery	Li-Ion 3.7 V, 2000 mAh
Runtime	Up to ~20 hours (depends on speed setting)
Charge time	~3 hours

Battery care

• Charge the battery at least once a month.
• Avoid fully discharging it when you can.
• For long storage, leave it at 40–60% charge.
• Expected life: ~500 charge cycles.
• Replace the battery through authorised service only - don’t open the device or swap battery types.

If the LED won’t light and the disc won’t move, the battery is empty - charge it. If it still won’t charge, try a different cable, gently clean the USB-C port, and if it persists contact support.