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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.

DIY total
~$95
vs
Commercial
$15,000
save 99%
136 views · 136 this week
~$95 BOM5 compatible robotsadds 1.2kg

What you'll be assembling

Pulling current matching products on AliExpress…

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.

Lista de materiales

GaN USB-C PD power supply (100W)
Wall-plug into 5-20V output, dock chooses 12V profile via PD negotiation
$35
ESP32-C3 mini
Dock controller — handshakes with robot, monitors current, exposes Wi-Fi status
$5
Spring-loaded pogo contacts (2x pairs)
Plus + minus, gold-plated, rated 8A. Mated to the robot's belly conductive strips
$12
N52 magnets (4x)
Side-rail alignment magnets, 30×10×5mm. Pull-strength tuned for the target robot weight
$8
Aluminum landing pad (30×30cm)
Anodized for surface durability, conductive strips routed underneath
$25
Wall-mount bracket (3D printed PA12-CF)
Holds the dock at 8° downward angle so debris drains off the pad
$6
Status RGB LED ring
Around the pad — green=charging, yellow=fault, blue=idle, red=protection trip
$4
Total estimado
$95

Robots compatibles

Variantes

  • Outdoor / IP65 variant
    Add 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 variant
    Bigger 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 variant
    Drop 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.

Instalación

  1. 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. 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. 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. 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.

Preguntas frecuentes

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.

Boston Dynamics Spot Dock
Boston Dynamics · $3,000-5,000
Visit ↗
Official Spot wireless charging dock. Industrial-grade, 24/7 supported. Required if your Spot is part of a fleet under BD's commercial support contract. Massively over-engineered for a single-robot home/lab setup.
Unitree Go2 charging stand (factory)
Unitree · $200-400
Visit ↗
The factory passive stand from Unitree. Doesn't dock automatically — the robot has to be placed on it manually. Way cheaper than BD but still significantly more than the DIY autonomous dock.
ANYbotics auto-charge station
ANYbotics · $8,000-15,000
Visit ↗
Industrial auto-charge for ANYmal-D fleets in oil & gas / power-plant inspections. Full IP66, redundant safety, certified for hazardous-area zones. Overkill unless you're running an industrial site.

Construí este addon

Abrí el builder con la especificación de este addon precargada. Ajustá los componentes, regenerá el BOM con precios de AliExpress en vivo, descargá el CAD OpenSCAD.

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DIY total
~$95save 99%
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