Introduction
Thank you for choosing the AeternaSol 20A Smart Car Battery Charger & 12V/24V Maintainer. This device is designed to efficiently charge and maintain a wide range of 12V and 24V batteries, including Lithium-Ion (NMC), LiFePO4, AGM, Gel, and Lead-Acid types. It features intelligent voltage detection, multiple charging modes, a 200-second booster function, pulse repair, and temperature compensation for optimal battery care. Please read this manual thoroughly before use to ensure safe and effective operation.
Safety Information
WARNING: Always follow these safety precautions to prevent injury or damage.
- Read all instructions before using the charger.
- Do not charge frozen batteries.
- Ensure proper ventilation during charging, especially for lead-acid batteries, as they can emit explosive gases.
- Avoid sparks or flames near the battery or charger.
- Wear eye protection and gloves when working with batteries.
- Disconnect the AC power before making or breaking connections to the battery.
- Keep out of reach of children.
- Do not expose the charger to rain or excessive moisture.
- If the power cord is damaged, it must be replaced by the manufacturer or a qualified service agent to avoid hazards.
Product Features
The AeternaSol Smart Car Battery Charger offers advanced features for comprehensive battery management:
- 20A High-Efficiency Charging: Provides 20A max for 12V systems and 10A for 24V systems.
- 12V/24V Auto-Recognition: Automatically detects battery voltage.
- Tri-Chemistry Dedicated Modes: Supports 12.6V Li-Ion (NMC), 14.6V LiFePO4, AGM, GEL, SLA, and Wet Lead-Acid batteries.
- 200s Booster Mode: Provides a targeted quick charge for 12V lead-acid batteries to assist with jump-starting.
- Advanced Pulse Repair: Utilizes high/low-frequency pulse technology to restore performance of sulfated lead-acid batteries.
- Temperature Compensation: Adjusts charging voltage based on ambient temperature (Winter/Summer Modes).
- Smart Heat Dissipation: Equipped with a high-efficiency cooling fan.
- 24/7 Safety Monitoring: Protection against reverse polarity, short circuit, over-current, and over-heating.
- Real-time Data Display: LCD shows voltage, current, temperature, and charge percentage.

Image: The AeternaSol 20A Smart Car Battery Charger connected to a lead-acid battery, illustrating its high-power charging capability and digital display.

Image: This charger is compatible with a wide range of 12V and 24V batteries found in motorcycles, cars, motoboats, trucks, golf cars, engineering vehicles, lawn mowers, and RVs.
Package Contents
Verify that all items are present in your package:
- AeternaSol 20A Smart Car Battery Charger Unit
- Battery Clamps (Red for positive, Black for negative)
- AC Power Cord
- User Manual
Setup
Follow these steps for initial setup:
- Prepare the Battery: Ensure the battery terminals are clean and free of corrosion. If charging a lead-acid battery with removable caps, check electrolyte levels and add distilled water if necessary.
- Connect Battery Clamps:
- Connect the RED positive (+) clamp to the positive (+) battery terminal.
- Connect the BLACK negative (-) clamp to the negative (-) battery terminal.
- Ensure connections are secure.
- Connect to AC Power: Plug the charger's AC power cord into a standard 110V AC wall outlet. The charger will power on and display current battery information.
- Select Charging Mode: Press the 'MODE' button to cycle through the available charging modes (Lithium, Car, AGM, Moto, LiFePO4, Repair, Booster). Select the mode appropriate for your battery type.
Operating Instructions
The charger features an intuitive interface and multiple operating modes.
Display Information

Image: The LCD display provides real-time information including charging voltage, current, temperature, and battery charge level.
The LCD screen provides real-time data:
- Voltage (V): Current battery voltage.
- Current (A): Charging amperage.
- Temperature (°C): Ambient temperature, used for compensation.
- Battery Level Indicator: Shows estimated charge percentage.
- Mode Indicator: Displays the currently selected charging mode.
Charging Modes Selection

Image: The charger's display showing the 7 available mode selections for different battery types and functions.
Press the 'MODE' button to cycle through the following options:
- LITHIUM (12.6V): For 12.6V Lithium-Ion (NMC) batteries.
- CAR: Standard charging for 12V lead-acid car batteries.
- AGM: For 12V AGM batteries.
- MOTO: For 12V motorcycle batteries (typically smaller lead-acid or AGM).
- LiFePO4 (14.6V): For 14.6V LiFePO4 batteries.
- REPAIR: For desulfating and reconditioning old or idle lead-acid batteries.
- BOOSTER: Emergency jump-start assist for 12V lead-acid batteries.
Charging Process

Image: A diagram detailing the 10-stage charging process, from battery diagnosis to float charging.
The charger employs a 10-stage charging process for optimal battery health:
- Battery Diagnosis
- Battery Desulphation
- Pre-charging
- Soft Start Charging
- Bulk Charging
- Constant Current Charging
- 1/2 Constant Current Charging
- Absorption Charging
- Float Charging
- Re-start Charge after Battery Discharged
Booster Mode (Jump Start Assist)

Image: The charger in 'Booster Mode', showing the 200-second countdown for emergency jump-start assist.
The 200-second Booster Mode is designed for 12V lead-acid batteries that require a quick burst of charge to start a vehicle. Select 'BOOSTER' mode, and the charger will deliver maximum current for 200 seconds. Monitor the countdown on the LCD. After the countdown, attempt to start your vehicle.
Repair Mode

Image: The charger in 'Repair Mode', indicating its function to address issues like long idle time, low voltage, and battery aging through low-frequency pulse technology.
The Repair Mode uses pulse technology to help restore the capacity of old, idle, or sulfated lead-acid batteries. Select 'REPAIR' mode and allow the charger to complete its cycle. This process can take several hours depending on the battery condition. Note that not all damaged batteries can be fully restored.
Official Product Videos
Video: An overview of the 20-Amp Car Battery Charger, highlighting its smart features and 12V/24V compatibility. This video demonstrates the charger's capabilities and ease of use.
Video: A detailed look at the 12V/24V 20 Amp Smart Battery Charger, focusing on its compatibility with Lead-Acid, Lithium, and LiFePO4 battery types. This video explains how to select the correct mode for your battery.
Video: Demonstrates the 20A Car Battery Charger in action, showcasing its smart automotive charging capabilities. This video provides a visual guide to connecting and operating the charger.
Maintenance
Proper maintenance ensures the longevity and performance of your charger:
- Cleaning: Wipe the charger casing with a dry cloth. Do not use solvents or abrasive cleaners.
- Cable Inspection: Regularly check the AC power cord and battery cables for any signs of damage, fraying, or exposed wires. Replace if damaged.
- Storage: Store the charger in a cool, dry place away from direct sunlight and extreme temperatures. Ensure clamps are clean and stored safely to prevent accidental short circuits.
- Ventilation: Keep the charger's ventilation openings clear of dust and debris to ensure proper cooling.
Troubleshooting
If you encounter issues, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Charger does not power on. | No AC power; faulty power cord. | Check AC outlet and power cord connection. Try a different outlet. |
| Charger displays error code or 'OFF'. | Reverse polarity; short circuit; battery not connected. | Verify correct clamp connections (+ to +, - to -). Ensure clamps are securely attached to battery terminals. |
| Battery not charging or charging slowly. | Incorrect mode selected; deeply discharged battery; faulty battery. | Ensure the correct battery type mode is selected. For deeply discharged lead-acid batteries, try Repair Mode. Test battery condition separately. |
| Charger gets hot during operation. | Normal operation; blocked ventilation. | Some heat is normal. Ensure ventilation openings are not blocked. If overheating persists, discontinue use and contact support. |
Specifications
| Feature | Detail |
|---|---|
| Product Dimensions | 18.7D x 7W x 9.5H Centimetres |
| Input Voltage | 110 Volts (AC) |
| Output Voltage | 24 Volts (Max) |
| Amperage | 20A (12V), 10A (24V) |
| Battery Compatibility | 12.6V Lithium-Ion (NMC), 14.6V LiFePO4, AGM, GEL, SLA, Wet Lead-Acid |
| Booster Mode | 200 seconds for 12V Lead-Acid batteries |
| Connector Type | Battery Clamp Connector / AC plug |
| Number of Ports | 1 |
Warranty and Support
AeternaSol products are manufactured to high-quality standards. For warranty information or technical support, please refer to the contact details provided with your purchase or visit the official AeternaSol website. Keep your proof of purchase for warranty claims.