1. Introduction
This manual provides essential information for the safe and effective use of your Powerextra 18-Volt 3500mAh replacement battery. This battery is designed to be compatible with various Skil 18-Volt cordless power tools, offering reliable power for your applications. Please read this manual thoroughly before using the battery to ensure proper operation and to maximize its lifespan.
2. Safety Instructions
Always observe the following safety precautions when handling and using the battery:
- Charging: Use only chargers specified by the tool manufacturer or Powerextra for this battery type. Incorrect chargers can cause fire, injury, or damage.
- Storage: Store the battery in a cool, dry place away from direct sunlight, heat sources, and moisture. Do not store in temperatures exceeding 122°F (50°C).
- Handling: Do not short-circuit the battery terminals. Avoid dropping, puncturing, or disassembling the battery. Do not expose the battery to water or rain.
- Disposal: Dispose of batteries responsibly according to local regulations. Do not dispose of batteries in household waste or by incineration.
- Damage: If the battery shows signs of damage, leakage, or overheating, discontinue use immediately and contact support.

Image 2.1: The Powerextra battery features a multiple protection system, including safeguards against short-circuit, over-heating, over-current, and under-voltage conditions to enhance safety and battery longevity.
3. Product Overview
The Powerextra 18-Volt 3500mAh replacement battery is engineered to provide reliable power for your Skil 18V cordless tools. It features premium NiMH cells and a robust design for durability and performance.
3.1 Key Features
- High Capacity: 3500mAh for extended run time.
- Voltage: 18 Volts, compatible with Skil 18V tools.
- Battery Type: Premium NiMH cells.
- No Memory Effect: Can be charged freely without reducing battery life.
- Integrated Protection: Built-in microchip prevents overcharging, over-current, over-heating, and under-voltage.
- Durable Casing: Constructed with ABS+PC material for enhanced resilience.

Image 3.1: A detailed view of the Powerextra 18-Volt 3500mAh replacement battery, showcasing its compact and robust design.

Image 3.2: This image highlights key design elements including the quick release push button for easy removal, the durable ABS+PC case material, and the precise interface design ensuring a secure fit with compatible tools.

Image 3.3: The Powerextra 18-Volt battery is shown alongside a charger and several Skil 18-volt cordless tools, illustrating its broad compatibility with the Skil 18V tool line.

Image 3.4: A visual comparison demonstrating the 3500mAh capacity of the Powerextra battery, indicating a longer run time compared to standard 3000mAh batteries.
4. Setup and Installation
4.1 Initial Charging
Before first use, fully charge the battery. Connect the battery to a compatible Skil 18V charger. The charger's indicator light will typically show the charging status. Refer to your charger's manual for specific charging instructions and times.
4.2 Installing the Battery
- Ensure the power tool is turned off.
- Align the battery with the battery port on the tool.
- Slide the battery into the tool until it clicks securely into place. Ensure it is fully seated and does not wobble.
4.3 Removing the Battery
- Ensure the power tool is turned off.
- Press the quick release button(s) on the battery.
- Slide the battery out of the tool.

Image 4.1: The Powerextra 18-Volt battery is shown securely installed in a cordless drill, demonstrating proper fit and integration with a compatible power tool.
5. Operating Instructions
Once the battery is fully charged and correctly installed in your Skil 18V cordless tool, the tool is ready for operation. Refer to your specific power tool's instruction manual for detailed operating procedures.
- Always ensure the battery is fully charged for optimal performance.
- Avoid completely draining the battery during use, as this can reduce its overall lifespan.
- If the tool's performance decreases, it indicates the battery needs recharging.
6. Maintenance
Proper maintenance ensures the longevity and performance of your Powerextra battery:
- Cleaning: Keep battery terminals clean and free from dirt or debris. Use a dry cloth to wipe the battery casing.
- Charging Cycles: For NiMH batteries, it is generally recommended to fully discharge the battery before recharging to prevent memory effect, although this battery is designed to minimize it.
- Long-Term Storage: If storing the battery for an extended period, charge it to approximately 50% capacity and store it in a cool, dry place. Recharge every 3-6 months to prevent deep discharge.
- Temperature: Avoid exposing the battery to extreme temperatures, both hot and cold, as this can degrade performance and lifespan.
7. Troubleshooting
If you encounter issues with your Powerextra battery, consider the following:
- Battery Not Charging:
- Ensure the battery is properly seated in the charger.
- Verify the charger is plugged into a working power outlet.
- Check for any visible damage to the battery or charger.
- Tool Not Operating:
- Confirm the battery is fully charged and securely installed in the tool.
- Test the battery in another compatible tool, if available.
- Ensure the tool itself is functioning correctly with a known good battery.
- Reduced Run Time:
- The battery may require a full charge cycle.
- Battery lifespan naturally decreases over time and with usage.
- Ensure the battery is not being used in extreme temperatures.
If problems persist, contact Powerextra customer support.
8. Specifications
| Specification | Value |
|---|---|
| Brand | Powerextra |
| Model Numbers (Replacement) | SB18C, SB18A, SB18B |
| Voltage | 18 Volts |
| Battery Capacity | 3500 Milliamp Hours (mAh) |
| Battery Cell Composition | NiMH |
| Recommended Uses | Power Tool |
| Package Dimensions | 6.1 x 3.7 x 3.46 inches |
| Item Weight | 0.01 ounces |
| ASIN | B075WRJDGW |

Image 8.1: This graphic summarizes key product details, including the 18-Volt rating, NiMH battery type, and 3500mAh capacity.
9. Warranty and Support
Powerextra provides a 30-day money-back guarantee and a 12-month limited warranty for this product. This warranty covers manufacturing defects and ensures your satisfaction with the battery's performance under normal use.
For warranty claims, technical support, or any inquiries regarding your Powerextra battery, please contact Powerextra customer service through the retailer where the product was purchased or visit the official Powerextra website for contact information.

