---
id: power-system
title: "Power System"
status: established
source_sections: "reference/sources/official-product-page.md, reference/sources/official-user-manual.md"
related_topics: [hardware-specs, safety-limits, deployment-operations]
key_equations: [battery_runtime]
key_terms: [battery_capacity]
images: []
examples: []
open_questions:
  - "Exact nominal battery voltage (calculated ~48V from 13-cell)"
  - "Power draw breakdown by subsystem (compute vs actuators vs sensors)"
  - "Charging time from empty to full"
  - "Low-battery cutoff voltage and behavior"
---

# Power System

Battery, power distribution, runtime, and charging for the G1.

## 1. Battery Specifications

| Parameter          | Value          | Unit | Source                 | Tier |
|-------------------|----------------|------|------------------------|------|
| Chemistry          | Lithium-ion (LiPo) | — | Official spec sheet   | T0   |
| Cell configuration | 13-cell series | —    | Official spec sheet    | T0   |
| Capacity           | 9,000          | mAh  | Official spec sheet    | T0   |
| Energy (estimated) | ~432           | Wh   | 9Ah × ~48V nominal     | T3   |
| Form factor        | Quick-release smart battery | — | Official spec sheet | T0 |

**Note on energy estimate:** A 13-cell LiPo at nominal 3.7V/cell = 48.1V nominal. 9Ah × 48.1V ≈ 432 Wh. This is a T3 inference — official Wh rating not published. [T3]

## 2. Charging

| Parameter          | Value              | Unit | Source              | Tier |
|-------------------|--------------------|------|---------------------|------|
| Charger input      | 100-240V AC, 50/60Hz | —  | Official spec sheet | T0   |
| Charger input current | 4A @ 350VA      | —    | Official spec sheet | T0   |
| Charger output     | 54V DC             | V    | Official spec sheet | T0   |
| Charger output current | 5A              | A    | Official spec sheet | T0   |
| Max charge power   | 270                | W    | 54V × 5A            | T3   |

## 3. Runtime Estimates

| Activity              | Runtime    | Source                | Tier |
|----------------------|------------|------------------------|------|
| Continuous operation   | ~2 hours   | Official spec sheet    | T0   |
| G1-D (wheeled variant) | Up to 6 hours | G1-D product page  | T0   |

Runtime varies significantly with activity profile. Walking with manipulation draws more power than standing idle. Specific power draw per activity mode not yet documented. [T3]

## 4. Cooling

- **System:** Local air cooling for motors and electronics [T0]
- **Motor cooling:** Efficient heat dissipation via hollow motor shaft design [T0]
- **Thermal monitoring:** Per-motor temperature sensors for overheating protection [T0]

## 5. Power Distribution

Power flows from the battery to three main consumers: [T3 — Inferred from architecture]

1. **Actuators** — All joint motors (largest consumer during locomotion)
2. **Compute** — Locomotion computer + development computer (Jetson Orin NX)
3. **Sensors & peripherals** — Cameras, LiDAR, microphones, speaker, WiFi/BT

The quick-release smart battery connector allows field battery swaps for extended operation.

## Key Relationships
- Powers: [[hardware-specs]] (entire platform)
- Constrains: [[deployment-operations]] (mission duration)
- Safety governed by: [[safety-limits]] (low-battery cutoff)
- Equations: [[equations-and-bounds]] (runtime formula)