1. Introduction
The NOCO NCP2 B603 Oil-Based Battery Terminal Protectors are designed to prevent corrosion on battery terminals. These anti-corrosion washers are made from 100-percent organic non-woven felt, saturated with an oil-based NCP2 battery corrosion preventative compound. This compound is formulated to last indefinitely without drying or evaporating, providing continuous protection against acid fumes that cause battery corrosion. They are suitable for both top-post and side-post battery terminal applications.
2. Product Components
Each package contains:
- 50 x NOCO NCP2 Oil-Based Battery Terminal Protectors (Anti-Corrosion Washers)

Image 1: NOCO NCP2 B603 Battery Terminal Protectors. The image shows a black container of NOCO NCP2 B603 battery terminal protectors with three individual black felt washers placed in front of it. The container has the NOCO logo and product information visible.
3. Installation Instructions (Setup)
Follow these steps to properly install the NOCO NCP2 B603 Battery Terminal Protectors:
- Clean Battery Terminals: Before installation, ensure that the battery terminals and cable connectors are clean and free of any existing corrosion. Use a battery terminal brush and a suitable battery cleaner if necessary.
- Identify Terminal Type: Determine if your battery uses top-post or side-post terminals. The NCP2 protectors are designed for both.
- For Top-Post Batteries: Place one protector over each battery post (positive and negative) before attaching the cable connectors. The protector should sit flush against the battery casing around the post.
- For Side-Post Batteries: The protectors feature a removable inner ring. Carefully remove the inner ring to adapt the protector for side-post applications. Place the modified protector around the side-post terminal before securing the cable.
- Secure Connections: Reattach and tighten the battery cable connectors to the terminals according to your vehicle's specifications. Ensure a secure connection.

Image 2: Installation steps for NOCO NCP2 B603 Battery Terminal Protectors. This image illustrates a two-step process: first, cleaning the battery terminal and cables, and second, placing the NCP2 Battery Terminal Protectors onto the terminal posts. It also suggests using NCP2 Battery Corrosion Preventative for additional protection.

Image 3: Universal application of NOCO NCP2 B603 for top-post and side-post batteries. The image shows how the protectors can be used on both top-post and side-post battery terminals, highlighting the removable inner ring for side-post applications.
4. Operating Principle
The NOCO NCP2 B603 protectors function as a passive corrosion inhibitor. Once installed, the oil-based compound saturating the felt washers creates a barrier that prevents corrosive acid fumes from reaching and reacting with the battery terminals and cable connectors. This continuous protection helps maintain optimal electrical conductivity and extends the lifespan of your battery and associated components.

Image 4: Comparison of corroded versus protected battery terminals. This image visually contrasts a severely corroded battery terminal with a clean, protected one, demonstrating the effectiveness of the NOCO NCP2 protectors in preventing corrosion.

Image 5: Oil-based formula protecting battery terminals. The image depicts the oil-based formula shielding and protecting battery terminals, emphasizing that the corrosion inhibitor grease does not dry or evaporate, providing lifetime protection.
5. Maintenance
The NOCO NCP2 B603 Battery Terminal Protectors are designed for long-lasting performance. The oil-based compound does not dry or evaporate, providing indefinite protection. Regular maintenance involves:
- Periodic Inspection: Periodically inspect the battery terminals and protectors for any signs of damage or excessive dirt accumulation.
- Cleaning: If dirt or debris accumulates on the protectors or terminals, gently wipe them clean with a cloth. Avoid using harsh chemicals that could degrade the protective compound.
- Reapplication: In rare cases of severe exposure or damage, the protectors may need replacement. Otherwise, they are intended to last the life of the battery.
6. Troubleshooting
These protectors are designed to prevent corrosion. If you observe corrosion on your battery terminals after installing the NCP2 B603 protectors, consider the following:
- Improper Installation: Ensure the protectors are correctly seated around the battery posts and that the cable connections are tight. Gaps can allow acid fumes to bypass the protection.
- Pre-existing Corrosion: The protectors prevent new corrosion but do not remove existing corrosion. Ensure terminals were thoroughly cleaned before installation.
- Battery Issues: Excessive gassing from a faulty battery can sometimes overwhelm protective measures. Consult a professional if you suspect battery issues.
7. Specifications
| Feature | Detail |
|---|---|
| Model Number | B603S |
| Quantity | 50 Protectors per pack |
| Formula Type | Oil-Based NCP2 Corrosion Preventative |
| Material | 100% Organic Non-Woven Felt |
| Application | Top-Post and Side-Post Batteries (with removable inner ring) |
| Item Weight | 8 ounces |
| Product Dimensions | 3.63 x 3.88 x 3.63 inches |
| Manufacturer | NOCO |
| Date First Available | October 30, 2010 |
8. Warranty Information
Specific warranty details for the NOCO NCP2 B603 Battery Terminal Protectors are not provided in this manual. For information regarding product warranty, please refer to the official NOCO website or contact NOCO customer support directly.
9. Support and Contact
For further assistance, technical support, or product inquiries, please visit the official NOCO website or contact their customer service department.
- Official Website: www.no.co
- Brand Store: NOCO Amazon Store





