1. Introduction
The GOOLOO S4 Smart Battery Charger is an advanced 4A 6V/12V battery charger and maintainer designed for a wide range of lead-acid batteries and 12V LiFePO4 batteries. It features a 10-level automatic charging process, automatic repair function for sulfated batteries, and an intuitive LCD screen for easy monitoring. This manual provides essential information for safe and effective operation, maintenance, and troubleshooting of your GOOLOO S4 charger.
2. Product Overview
2.1 Components
The GOOLOO S4 Smart Battery Charger comes with the following components:
- GOOLOO S4 Charger Unit
- Battery Clamps (Red for Positive, Black for Negative)
- O-Ring Terminal Connectors
- AC Power Cord
- User Manual

This image displays the GOOLOO S4 Smart Battery Charger along with its essential accessories. The main charger unit is visible, featuring an LCD screen and mode button. To the right, the red and black battery clamps are shown, used for connecting to battery terminals. Above them, the O-ring terminal connectors are also present, offering an alternative connection method.
2.2 Key Features
- Wide Battery Compatibility: Charges 6V/12V lead-acid batteries (AGM, GEL, SLA, Flooded, Calcium, Maintenance-Free) and 12V LiFePO4 batteries (6-100 Ah).
- 10-Level Automatic Charging: Monitors and optimizes the entire charging process, including maintenance charging.
- Automatic Battery Repair: Detects and repairs sulfated batteries to improve performance and longevity.
- Smart LCD Display: Provides real-time feedback and diagnostic information, including voltage and charging status.
- Multiple Security Protections: Equipped with SuperSafe technology for protection against short circuits, overloads, reverse polarity, overcharge, and overheating.
- IP65 Waterproof: Designed to be used in various weather conditions, including rain.
- Temperature Compensation: Adjusts charging parameters for optimal performance in both cold (-4°F) and hot (104°F) weather.

This image highlights the versatility of the GOOLOO S4 charger, showing it connected to different types of 6V and 12V lead-acid batteries. Text overlays indicate compatibility with AGM/C, GEL, LFP, EFB, STD, WET, CA, and 12V LiFePO4 batteries, emphasizing its broad application.

The image illustrates the charger's compensation charging process, showing the GOOLOO S4 unit connected to a battery. The LCD screen displays '14.3V', indicating the charging voltage. The visual representation suggests the charger is actively reconditioning, restoring, and maintaining the battery through a fully automatic charging cycle.

This graphic details the comprehensive safety features of the GOOLOO S4 charger. Icons represent protections against short circuit, overload, low voltage, high voltage, overcharge, over temperature, reverse connection, and over current, all under the 'SUPERSAFE' technology.

The image visually demonstrates the charger's ability to adapt to extreme temperatures. One side shows the charger in a snowy, cold environment (-4°F), preventing under-charging. The other side depicts it in a hot, desert setting (104°F), preventing over-charging, highlighting its robust thermal management.
3. Safety Information
Please read and understand all safety information before using the GOOLOO S4 Smart Battery Charger. Failure to follow these instructions may result in electric shock, fire, or serious injury.
- Always wear eye protection and protective clothing when working with batteries.
- Ensure the charging area is well-ventilated.
- Do not charge frozen or damaged batteries.
- Keep sparks, flames, and smoking materials away from batteries.
- Never touch uninsulated battery cables or terminals.
- Disconnect the AC power from the charger before connecting or disconnecting the battery clamps.
- Do not expose the charger to excessive moisture or immerse it in water, despite its IP65 rating.
- Keep out of reach of children.
4. Setup
Follow these steps to set up your GOOLOO S4 Smart Battery Charger:
- Unpack the Charger: Carefully remove all components from the packaging and inspect them for any damage.
- Prepare the Battery: Ensure the battery terminals are clean and free of corrosion. If necessary, clean them with a wire brush.
- Connect to Battery:
- Connect the RED positive (+) clamp or O-ring terminal to the positive (+) battery terminal.
- Connect the BLACK negative (-) clamp or O-ring terminal to the negative (-) battery terminal.
- For vehicle batteries, connect the negative clamp to the vehicle chassis away from the battery and fuel line if the negative terminal is connected to the chassis.
- Connect to AC Power: Plug the charger's AC power cord into a standard electrical outlet (100-240V AC). The charger will power on and display the current battery voltage.

This image shows the GOOLOO S4 Smart Battery Charger in use, with its clamps securely connected to a car battery within an engine bay. The charger's LCD screen is visible, displaying charging information, indicating an active charging process.
5. Operating Instructions
The GOOLOO S4 charger operates largely automatically. Here's how to use it:
- Power On: Once connected to both the battery and AC power, the charger will automatically power on and display the battery voltage.
- Select Charging Mode: Press the 'MODE' button to cycle through the available charging modes (e.g., 6V STD, 12V STD, 12V AGM/GEL, 12V LiFePO4, REPAIR). Select the mode appropriate for your battery type. The charger has an automatic memory function that restores the last setting when reconnected (except for 6V STD and power supply mode).
- Automatic Charging: Once a mode is selected, the charger will automatically begin the 10-level charging process. The LCD screen will display charging progress, voltage, and current.
- Battery Repair Function: If your battery is sulfated or deeply discharged, select the 'REPAIR' mode. The charger will attempt to restore the battery's capacity using pulse repair technology. Note: This function may not repair severely damaged or dead batteries.
- Charging Completion: The charger will automatically switch to maintenance mode once the battery is fully charged, preventing overcharging. The LCD will indicate 'FULL' or a similar status.
- Disconnecting: To disconnect, first unplug the AC power cord from the wall outlet, then disconnect the negative (-) clamp/terminal, followed by the positive (+) clamp/terminal.

A pair of hands holds the GOOLOO S4 charger, providing a clear view of its intelligent LCD screen. The screen displays '14.3V' and a battery charge indicator, demonstrating the user-friendly interface for monitoring the charging status.
6. Maintenance
Proper maintenance ensures the longevity and optimal performance of your GOOLOO S4 charger:
- Cleaning: Disconnect the charger from all power sources before cleaning. Wipe the exterior with a soft, damp cloth. Do not use harsh chemicals or abrasive cleaners.
- Cable Inspection: Regularly inspect the AC power cord and battery cables for any signs of damage, fraying, or loose connections. Replace if damaged.
- Storage: Store the charger in a cool, dry place when not in use. Keep it away from direct sunlight, excessive heat, and moisture.
7. Troubleshooting
If you encounter issues with your GOOLOO S4 charger, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Charger does not turn on. | No AC power; Incorrect battery connection; Battery voltage too low. | Check AC outlet and power cord. Ensure correct polarity (red to +, black to -). If battery voltage is below 2V, the charger may not detect it. |
| Battery not charging or charging slowly. | Incorrect mode selected; Battery is severely sulfated or damaged; Loose connections. | Verify the correct charging mode for your battery type. Try the 'REPAIR' mode. Check all connections for tightness. Have the battery tested by a professional. |
| LCD displays an error code. | Reverse polarity; Over-temperature; Short circuit. | Disconnect immediately. Check battery connections for reverse polarity. Allow charger to cool down if it's hot. Inspect cables for shorts. |
| Charger gets hot during operation. | Normal operation; Poor ventilation; Overload. | Some heat is normal. Ensure adequate ventilation around the charger. If excessively hot, disconnect and allow to cool. Ensure battery capacity is within charger's range. |
If the problem persists after trying these solutions, please contact GOOLOO customer support.
8. Specifications
| Feature | Specification |
|---|---|
| Model | DE-S4 |
| Brand | GOOLOO |
| Input Voltage | 100-240V AC, 50/60Hz (Standard) |
| Output Voltage | 6V DC / 12V DC |
| Charging Current | 4A (12V), 2A (6V) |
| Battery Capacity Range | 6-100 Ah |
| Supported Battery Types | AGM, GEL, SLA, Flooded, Calcium, Maintenance-Free, 12V LiFePO4 |
| Waterproof Rating | IP65 |
| Operating Temperature | -4°F to 104°F (-20°C to 40°C) |
9. Warranty and Support
GOOLOO is committed to providing high-quality products and excellent customer service.
- Warranty: The GOOLOO S4 Smart Battery Charger comes with an 18-month warranty from the date of purchase.
- Return Policy: Enjoy a 30-day unconditional return guarantee.
- Customer Support: GOOLOO offers 24/7 customer support and lifetime technical assistance.
For any inquiries, technical support, or warranty claims, please visit the official GOOLOO website or contact their customer service team directly.





