AQEX STUBBORN BALANCE ZERO UPS HAT @RPi Zero 2 WH
Sold by AQEX world
$63.03
No tax for United States [change]
Technical Data Sheet: Stubborn Balance Zero v1.0
Ultra-Durable Maintenance-Free Hybrid Supercapacitor UPS HAT for Raspberry Pi Zero
Official Product Page: https://www.aqex.eu/stubborn-balance-zero-raspberry-pi-zero-ups-hat-hybrid-supercap.html
1. Product Concept & Strategic Advantages
The Stubborn Balance Zero is a specialized uninterruptible power supply designed for the Raspberry Pi Zero family. Unlike traditional battery-based systems, it utilizes Hybrid Supercapacitor (HSC) technology to provide a maintenance-free, high-endurance power backup solution for industrial and remote IoT applications.
Strategic advantages:
- Extended Runtime: Offers significantly higher energy density and longer backup power duration compared to standard supercapacitors.
- Extreme Longevity: The HSC technology supports up to 50,000 charge cycles, outlasting traditional Li-ion batteries.
- Maintenance-Free: No chemical aging typical of batteries; ideal for hard-to-reach deployments.
- Superior Temperature Stability: Operates reliably in environments where standard batteries would fail.
- Compact Form Factor: Designed specifically to match the Raspberry Pi Zero's footprint.
- Zero Maintenance: No periodic battery replacements required during the typical lifecycle of the equipment.
2. Comprehensive Technical Specifications
| Parameter | Value | Condition / Detailed Notes |
|---|---|---|
| Input Voltage (USB-C) | 5.0V – 5.2V | Minimum 2A - 3A recommended |
| Output Voltage | 5.0V DC | Regulated for Raspberry Pi Zero |
| Storage Technology | Hybrid Supercapacitor | High energy density with long cycle life |
| Max Continuous Load | 3.5A | Enhanced current delivery for RPi 5 + Peripherals |
| Cycle Life | ~50,000 Cycles | Industrial grade durability |
| GPIO Interface | 40-pin Header | Pass-through design for stacking |
| Switchover Time | 100 – 300 μs | No-reboot guaranteed transition |
Design Note: The Offline topology ensures almost zero power loss and heat generation during standard operation. A momentary (<1ms) voltage transient occurs during power failure; however, the Raspberry Pi's internal regulation easily filters this, ensuring zero system instability or reboot.
3. Power Management & Protection
| Feature | Specification |
|---|---|
| Logic Control | Hardware-level voltage monitoring |
| Safety | Protected against over-discharge and input voltage fluctuations |
| Input Tuning | Potentiometer for input threshold calibration |
| Restart Logic | Automatic recovery after power restoration in AUTO mode |
4. User Interfaces & Configuration
4.1 Mode Selection (Switch 4)
- OFF: Complete power cut.
- ON: Immediate power-up when power (internal or external) is available.
- AUTO: Intelligent start-up logic; only boots the Pi when the battery reaches the "Min" energy level.
4.2 GPIO Communication
The system utilizes a 3-pin GPIO interface for OS-level integration. The following pins are used on the 40-pin Raspberry Pi header:
- PFO (Power Fail): GPIO 17 (Pin 11) — Signals external power loss (HIGH = OK / LOW = Backup Mode).
- LIM (Limit): GPIO 27 (Pin 13) — Signals that the battery has reached the critical low threshold.
- SHD (Shutdown): GPIO 22 (Pin 15) — Handshake signal. The UPS cuts power after the OS pulls this pin LOW (or the daemon signals a halt).
5. Visual Diagnostics (LED Indicators)
| LED | Color | Status / Meaning |
|---|---|---|
| External Power | Green | Primary 5V power source detected. |
| Full | Green | Battery fully charged (>3.9V). |
| Min | Green | Sufficient energy for a safe boot-shutdown cycle. |
| Safe | Yellow | Sufficient energy for a safe shutdown cycle. |
| Low | Red | Critical level. Immediate shutdown required. |
6. Intelligent Power Management (IPM)
- Safe-Start Logic: Prevents "brown-out" loops by ensuring the Pi only starts when the battery can support the peak current of the boot process.
- Shutdown Guard: Monitors the Pi's state and ensures power is only cut after the operating system has safely unmounted the filesystem.
- Input Threshold Tuning: Onboard potentiometer allows adjustment for voltage drops caused by long input cables.
7. Estimated Runtimes with Raspberry Pi Zero2 WH
| HSC Capacity | No Load | 100% Load |
|---|---|---|
| 450F | 46 min | 13 min |
| 850F | 60 min | 22 min |
| 1100F | 105 min | 28 min |
8. Software Support
- qups-guard: Native open-source daemon for automated monitoring and safe shutdown.
- Compatibility: Fully compatible with Raspberry Pi OS (Debian-based).
- Repository: github.com/aqexhu/qups-guard
HW Version: 1.0 | Released: 2025 Manufacturer: AQEX Electronics | aqex.eu
Links to code and documentation
Shipping policy
📦 Shipping Policy
Thank you for supporting independent makers! We strive to get your hardware into your hands as quickly and safely as possible.
1. Processing and Handling
Dispatch Time: Most orders are processed within 2–3 business days, 90% is processed same day.
Tracking: We recommend selecting Tracked Shipping at checkout for peace of mind. Once your order is shipped, you will receive an automated email with your tracking number and a link to follow its progress.
2. Shipping Rates & Delivery Times
Shipping costs are calculated at checkout based on the total weight of your order and your destination.
3. EU Taxes, VAT, and Customs (IOSS)
We use Lectronz’s built-in IOSS (Import One-Stop Shop) scheme to make your import process as smooth as possible.
Orders under €150: * VAT is collected at checkout. You will see the VAT rate for your specific country applied to your total.
No "Surprise" Fees: Because we use IOSS, your package should clear customs quickly without additional handling fees or import taxes upon arrival.
Orders over €150: VAT is not collected at checkout. You will be responsible for paying VAT and any applicable customs duties to your local postal service or courier upon delivery.
Intra-EU Shipping: If this store is shipping from within the EU to another EU country, no customs duties apply, and VAT is handled according to standard EU distance selling rules.
4. Shipping Locations
We currently ship to all EU member states. If your country is not listed at checkout, please contact us for a custom shipping quote.
5. Returns & Damaged Goods
14-Day Right of Withdrawal: As per EU law, you have 14 days to return your order for any reason, provided it is in its original condition.
Damaged Items: If your hardware arrives damaged, please take photos of the packaging and the product immediately and contact us through the Lectronz messaging system. We will arrange a replacement or refund.
