1. Product Overview
The Varstrom Large Ebike Controller Box is a durable plastic enclosure designed to protect your ebike's controller or battery from environmental elements such as water, dust, and moisture. Its sealed construction ensures enhanced protection and reliability, extending the lifespan of your electronic components. This large-sized case offers broad compatibility with various ebike controllers, provided their dimensions fit within the specified internal measurements.

Figure 1: Varstrom Large Ebike Controller Box and accessories.
2. Package Contents
The package includes the following items:
- 1 x Large Controller Box
- 2 x Fixing Clips
- 4 x Mounting Screws
- 4 x Fixing Screws
3. Specifications
| Feature | Detail |
|---|---|
| Material | Plastic |
| Controller Box Size (External) | Approx. 9.8" (25cm) L x 4.3" (11cm) W x 3" (7.8cm) H |
| Inner Size (Max Controller Dimensions) | Approx. 7.85" (20cm) L x 3.4" (8.6cm) W x 1.9" (4.8cm) H |
| Mounting Screw Size | Approx. 4 x 17mm / 0.15 x 0.67inch |
| Fixing Screw Size | Approx. 4 x 10mm / 0.15 x 0.39inch |
| Fixing Clip Size | Approx. 55 x 22mm / 2.16 x 0.86inch |
| Weight | Approx. 0.3kg |
| Special Feature | Waterproof |
Important Note: This product is a controller box only; the ebike controller is not included. Please ensure your controller's dimensions are less than 7.85" L x 3.4" W x 1.9" H before purchase to ensure compatibility.

Figure 2: Detailed dimensions of the controller box.
4. Installation
Follow these steps to install the Varstrom Large Ebike Controller Box on your bicycle frame:
- Prepare the Mounting Area: Identify a suitable location on your ebike frame for the controller box. Ensure there is enough space and that the surface is clean.
- Attach the Mounting Plate: The bottom part of the controller box acts as a mounting plate. Position it on the frame and use the provided fixing clips and screws to secure it. If the standard screws are not long enough for your frame, use the included extension screws.
- Insert the Controller: Place your ebike controller inside the main body of the box. Ensure all wires are routed correctly through the designated openings to prevent pinching or damage.
- Secure the Box: Align the top cover with the mounting plate and secure it using the remaining screws. Ensure a tight seal to maintain waterproof and dustproof integrity.
- Final Check: Verify that the controller box is firmly attached to the frame and that all screws are tightened. Check for any loose connections or exposed wires.

Figure 3: Visual guide for attaching the mounting plate to the bicycle frame.

Figure 4: Controller placement and internal dimensions for fit verification.

Figure 5: Internal view showing screw points for secure closure.
Installation Video Reference:
Video 1: Installation demonstration of a large controller box for 12mosfets 1000W-1500W motors.
Video 2: Overview of a large controller box, including internal dimensions and fitting a controller.
Video 3: Overview of a small controller box, demonstrating internal dimensions and controller fitting (useful for comparison).
5. Usage Guidelines
Once installed, the controller box provides a protective enclosure for your ebike's electronic components. Ensure that all cables are neatly organized within the box to prevent interference or damage. The sealed design helps maintain the integrity of your controller in various weather conditions.

Figure 6: The controller box securely mounted on an ebike frame.
6. Maintenance
To ensure the longevity and effectiveness of your Varstrom Large Ebike Controller Box, consider the following maintenance tips:
- Regular Cleaning: Periodically wipe down the exterior of the box with a damp cloth to remove dirt and debris. Avoid using harsh chemicals that may damage the plastic.
- Check Screws: Occasionally inspect all mounting and fixing screws to ensure they remain tight. Vibrations from riding can sometimes loosen screws over time.
- Inspect for Damage: Regularly check the box for any cracks or damage that could compromise its waterproof and dustproof properties. Replace if significant damage is found.
7. Troubleshooting
If you encounter issues with your controller box, consider these common troubleshooting steps:
- Controller Does Not Fit: Double-check the internal dimensions of the controller box against your ebike controller's measurements. Ensure your controller is within the specified limits (7.85" L x 3.4" W x 1.9" H).
- Loose Mounting: If the box feels loose on the frame, re-tighten all mounting and fixing screws. Ensure the fixing clips are correctly positioned around the frame.
- Water/Dust Ingress: If you suspect water or dust has entered the box, inspect the seal around the edges and ensure all screws are tightly fastened. Check for any cracks in the plastic.
8. Warranty & Support
The Varstrom Large Ebike Controller Box comes with the following warranty:
- 30 Days Return: You may return the product within 30 days of purchase.
- 90 Days Replacement: A replacement is available within 90 days of purchase for manufacturing defects.
For further assistance or support, please contact Varstrom customer service through the retailer where the product was purchased.



