Universal magnetic charging dock for quadruped robots
Wall-mounted dock with magnetic alignment, 5A USB-C PD output and a contact pad that fits Unitree Go2, Spot and Anymal. The robot drives onto the pad and charges without a tether.
What you'll be assembling
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Most consumer-class quadruped robots ship with a manual charging brick — you find the robot, flip it over, plug a barrel jack into a port near the spine, wait 90 minutes. The factory accessory is a wall-wart, not a dock. For deployments where the robot needs to operate unattended (security patrol, agricultural inspection, lab demos that span multiple shifts), the missing piece is a passive contact-pad dock that the robot can find and drive onto on its own.
The magnetic-alignment approach is mechanically forgiving: the dock has a 30cm landing pad with a tapered ramp, four neodymium magnets on the sides that gently pull the robot into position once it's within 4-5cm of the contact pad, and a pair of spring-loaded copper contacts that mate with conductive strips on the robot's belly. The robot doesn't need to land perfectly straight — the magnets handle ±15° of yaw error and ±3cm of lateral offset.
The control is two-wire: when the robot's belly contacts touch the dock pads, a small current flows through a 100Ω detection resistor in the dock; the dock's MCU (an ESP32) sees the voltage drop, validates with a CAN handshake (or just timing, depending on the robot model), and engages the 5A USB-C PD supply. If the robot moves off-center or rolls away, the contact breaks and power cuts within 50ms.
Nomenclature
Robots compatibles
Variantes
- Outdoor / IP65 variantAdd a hinged silicone flap that closes over the contacts when no robot is docked. Bumps cost by ~$15 but lets the dock survive rain on a covered patio.
- Multi-robot variantBigger landing pad (50×50cm), four contact zones with independent PD lanes — fits a small fleet of two robots that share a single dock by alternating. Useful for inspection setups.
- Solar-fed off-grid variantDrop the wall-plug, feed from a 200W solar panel + MPPT + 12V LiFePO4 battery. Self-sustaining for outdoor deployments where the robot must keep working without grid.
Installation
- 1.Mount the wall bracket at the robot's standing belly height minus 4cm — for Go2 that's 28cm, for Spot 36cm, for Anymal-D 50cm. The robot will autoland by lowering its body once close to the pad.
- 2.Route the conductive strips on the robot's belly: glue 5mm copper foil tape running 8cm along the spine on either side of the centerline. Solder a JST-XH pigtail to the existing battery's pos/neg taps.
- 3.Configure the robot's homing waypoint via its SDK (Go2 ROS2 node, Spot Boston Dynamics SDK) to drive to a point 15cm in front of the pad, lower body, then crawl forward 12cm.
- 4.Pair the dock to your network via the ESP32's BLE setup mode (default app: ESPHome dashboard). Once paired, dock state appears as a Home Assistant entity.
FAQ
Does it work with the factory wireless chargers some robots have?
No — Go2 and Spot use galvanic charging via specific contact ports. Wireless (Qi-style) chargers for quadrupeds are still rare; this dock is contact-based.
What if the robot misaligns and only one contact connects?
The MCU detects asymmetric current and refuses to engage power. Robot's own undervoltage protection plus a fault buzzer on the dock alert you.
How long does charging take?
Go2 (15Ah pack) is full from 20% in about 75 minutes at 5A. Spot's bigger pack takes ~110 min. Slightly slower than the factory 8A charger but easier on cell longevity.
Can it survive being walked on?
Yes — the aluminum pad is 4mm thick. We'd recommend not walking on it but it doesn't fail under foot pressure.
Don't want to build it? Buy commercial
Vet-supply and behavioral-product vendors that solve the same need without DIY assembly. We don't earn commission from these — they're listed because they're the legitimate non-DIY path.
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