Overview
This article covers which batteries the FieldPrinter 2 uses, how long they last, how to charge them, and best practices for battery management in the field.
What's Included in the Box
The FieldPrinter 2 ships with:
- 2× Milwaukee M18 XC5.0 batteries
- 1× Standard Milwaukee M18 charger
Compatible Batteries
The FieldPrinter 2 works with the Milwaukee M18 battery platform. Only use name-brand Milwaukee M18 batteries — third-party or off-brand batteries are not supported and may affect performance or cause unexpected behavior.
| Battery | Comes with robot? | Notes |
|---|---|---|
| Milwaukee M18 XC5.0 | ✅ Yes (2 included) | Standard battery; ships with the robot |
| Milwaukee M18 XC8.0 | No | Maximum supported capacity; longest runtime per charge |
| Smaller M18 batteries (e.g., 3.0Ah) | No | Supported; shorter runtime per battery |
Larger batteries fit the robot and extend how long you can print before swapping. Smaller batteries can work but will need swapping more frequently.
Runtime
On a fully charged Milwaukee M18 XC5.0 (5Ah) battery, the FieldPrinter 2 runs approximately 3–4 hours of continuous operation or roughly half a workday. Actual runtime varies based on:
- Print speed and job complexity
- Navigation intensity (obstacles, re-stationings)
- Battery age and current charge level
- Ambient temperature
To keep the robot running all day without stopping, have the spare battery available and keep it charging throughout the session. If jobsite power is not available, consider supplying a third battery.
Low Battery Warning
When the battery is getting low, the robot will beep to alert you before it fully depletes. This gives you time to perform a hot swap and keep printing without interruption — don't wait for the robot to shut off on its own.
Hot-Swapping Batteries
The FieldPrinter 2 supports hot-swapping; you can swap a depleted battery for a charged one without powering the robot down, allowing uninterrupted operation.
To hot-swap:
- Have a fully charged Milwaukee M18 battery ready before the swap.
- Remove the depleted battery from the robot.
- Insert the charged battery immediately.
- Wait briefly for the robot to confirm power is restored, then continue.
⚠️ If the radio doesn't reconnect after a hot swap: This is a known issue unrelated to the battery itself. Perform a full robot reboot: power the robot off, wait 10–15 seconds, then power it back on. See Radio Does Not Reconnect After Hot-Swapping the Battery for full details.
Charging
The included Milwaukee M18 standard charger works with all compatible M18 batteries. Additional Milwaukee M18 chargers are sold separately at most major hardware stores.
Tips for field readiness:
- Charge all batteries the night before or before arriving onsite.
- Keep spare batteries on the charger throughout the print session so a charged battery is always ready when the robot beeps.
- Avoid leaving batteries on the charger for extended periods after they're full.
- Don't expose batteries to extreme heat (direct sunlight in a hot truck, for example).
Frequently Asked Questions
Can I use third-party or off-brand M18 batteries? No. Only name-brand Milwaukee M18 batteries are supported. Off-brand batteries are not recommended and may cause unexpected behavior.
What's the largest battery the robot supports? The Milwaukee M18 XC8.0. It fits the robot and provides the longest runtime per charge.
What happens if the robot runs out of battery mid-print? The robot will beep to warn you before the battery fully depletes; swap in a charged battery when you hear it. If the robot does shut off, insert a charged battery (and reboot if necessary) then re-station before resuming. Plan swaps during natural workflow breaks to avoid interruptions.
Does the charger work with all M18 batteries? Yes. The standard Milwaukee M18 charger included with the robot charges all compatible M18 batteries.