1. Introduction
This manual provides essential instructions for the safe and effective use of your SigmasTek SP12-7.5HR (12V7.5AH/T2) Rechargeable Sealed Lead-Acid Battery, designed as a replacement for the Upsonic PCMIGHT 35 UPS system. Please read this manual thoroughly before installation and operation to ensure proper handling and longevity of the product.
2. Safety Information
Observe the following safety precautions to prevent injury or damage to the battery and connected equipment:
- Do not short-circuit the battery terminals. This can cause severe burns, fire, or explosion.
- Do not expose the battery to open flames or excessive heat.
- Do not disassemble or modify the battery. There are no user-serviceable parts inside.
- Wear appropriate personal protective equipment (PPE) such as gloves and eye protection when handling batteries.
- Ensure adequate ventilation when charging or operating the battery.
- Keep out of reach of children.
- Proper Disposal: This battery contains lead (Pb) and must be recycled or disposed of according to local regulations. Do not dispose of in household waste.
3. Product Overview
The SigmasTek SP12-7.5HR (12V7.5AH/T2) is a high-quality, maintenance-free, sealed lead-acid (SLA) battery utilizing Absorbent Glass Mat (AGM) technology. It is designed for reliable power delivery in UPS systems and other applications requiring a 12V, 7.5Ah power source.
Key Features:
- Absorbent Glass Mat (AGM) Technology
- Maintenance-Free Design with Spill Proof Construction
- U.L. Recognized and CE Certified
- Brand New, Factory Fresh

Image of the SigmasTek SP12-7.5HR (12V7.5AH/T2) Rechargeable Sealed Lead-Acid Battery, showing its terminals and label with charging instructions.
4. Setup and Installation
This battery is intended as a replacement for the Upsonic PCMIGHT 35 UPS battery. Follow these general steps for installation:
- Power Down: Ensure the UPS system is completely powered off and disconnected from the main power supply.
- Access Battery Compartment: Refer to your UPS system's manual for instructions on how to safely access its battery compartment.
- Disconnect Old Battery: Carefully disconnect the existing battery, noting the polarity (positive and negative terminals). Disconnect the negative terminal first, then the positive.
- Remove Old Battery: Extract the old battery from the compartment.
- Insert New Battery: Place the new SigmasTek replacement battery into the compartment.
- Connect New Battery: Reconnect the existing cables and hardware to the new battery. Ensure correct polarity: connect the positive terminal first, then the negative.
- Secure Compartment: Close and secure the UPS battery compartment.
- Initial Charge: Connect the UPS to the main power supply and allow the battery to undergo an initial charge cycle as recommended by your UPS manufacturer.
Important: You must use the existing cables and hardware from your UPS system to connect your replacement battery.
5. Operating Instructions (Charging)
The SigmasTek SP12-7.5HR battery is a rechargeable unit. Proper charging is crucial for its performance and lifespan. The following charging parameters are recommended:
- Floating Use (Standby): 13.5V ~ 13.8V
This voltage range is for applications where the battery is continuously connected to a power source and kept at full charge, such as in a UPS system. - Cycle Use (Deep Discharge/Recharge): 14.4V ~ 15.0V
This voltage range is for applications where the battery is regularly discharged and then recharged. - Initial Current: Less than 2.1A
The initial charging current should not exceed 2.1 Amperes to prevent damage to the battery.
Always use a charger compatible with sealed lead-acid batteries and adhere to the charging specifications provided by your UPS system or charger manufacturer.
6. Maintenance
The SigmasTek SP12-7.5HR battery features a maintenance-free design. However, periodic checks can help ensure optimal performance:
- Visual Inspection: Periodically inspect the battery for any signs of physical damage, cracks, or leaks.
- Terminal Connections: Ensure that the battery terminals and connections are clean, tight, and free from corrosion. Clean terminals with a wire brush if necessary.
- Storage: If storing the battery for an extended period, ensure it is fully charged and stored in a cool, dry place. Recharge every 3-6 months to prevent deep discharge.
7. Troubleshooting
If you experience issues with your replacement battery, consider the following:
- Battery Not Charging: Verify that all connections are secure and that the UPS or charger is functioning correctly. Check the input power to the UPS.
- Short Runtime: Ensure the battery has undergone a full charge cycle. If the issue persists, the battery may not be fully charged, or there might be an issue with the UPS's charging circuit.
- Overheating: If the battery feels excessively hot during charging or operation, immediately disconnect it and contact support.
For persistent issues, consult your UPS system's troubleshooting guide or contact SigmasTek customer support.
8. Specifications
| Brand | SigmasTek |
| Model Number | UPSonPCMIGHT35 (SP12-7.5HR) |
| Product Dimensions | 5.95 x 2.56 x 3.7 inches |
| Item Weight | 5.25 pounds |
| Battery Cell Composition | Lead Acid (AGM) |
| Recommended Uses | UPS (Uninterruptible Power Supply) |
| Unit Count | 1 Count |
| Reusability | Rechargeable |
| Certifications | U.L. Recognized, CE Certified |
9. Warranty and Support
Your SigmasTek Upsonic PCMIGHT 35 UPS Replacement Battery comes with a 1-year warranty from the date of purchase. This warranty covers manufacturing defects under normal use.
For warranty claims, technical support, or any questions regarding your battery, please visit the official SigmasTek website at www.sigmastek.com or contact their customer service directly.
