1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your ATEM POWER 40A DC to DC Battery Charger. This charger is designed to efficiently charge various battery types, including AGM, Gel, Calcium, Lead Acid, and LiFePO4, in 4WDs, RVs, campers, and trailers. Please read this manual thoroughly before use to ensure proper function and safety.
Image 1.1: The ATEM POWER 40A DC to DC Battery Charger with its included Anderson style plugs.
2. Safety Information
Observe the following safety precautions to prevent injury or damage to the charger and connected equipment:
- Ensure all connections are secure and correctly polarized before operation.
- Do not expose the charger to rain, moisture, or extreme temperatures.
- Install the charger in a well-ventilated area to prevent overheating.
- Always disconnect power before performing any maintenance or installation procedures.
- This device is intended for 12V DC systems only. Do not connect to 24V or higher systems.
- Consult a qualified electrician for complex installations or if you are unsure about any wiring procedures.
3. Product Features
The ATEM POWER 40A DC to DC Battery Charger incorporates several advanced features for optimal battery management:
- Reverse Charging Capability: Allows charging of the start battery from the auxiliary battery.
- Wide Battery Compatibility: Supports AGM, Gel, Calcium, Lead Acid, and LiFePO4 battery types.
- MPPT Solar Input: Integrated Maximum Power Point Tracking (MPPT) controller for efficient solar charging.
- Intelligent 3-Stage Charging: Optimizes charging for efficiency and extends battery lifespan.
- LiON Mode: Automatically activates sleeping LiFePO4 batteries.
- Comprehensive Protection: Includes reverse polarity, overvoltage, over-temperature, charge timeout, and lithium battery BMS safeguards.
- DC Charging Priority: Prioritizes vehicle battery input over solar input when both are available and meet startup conditions.
Image 3.1: The charger is compatible with multiple battery chemistries.
Image 3.2: The charger includes multiple protection features for safe operation.
4. Package Contents
Verify that all items are present in the package:
- 1 x ATEM POWER 40A DC to DC Charger with Anderson Style Plugs
- 3 x Anderson Style Plugs (additional for custom wiring)
- 1 x User Manual
Image 4.1: The complete package contents.
5. Setup and Installation
5.1. Connection Overview
The charger is equipped with Anderson style plugs for convenient wiring. Refer to the diagram below for connection details:
Image 5.1: Anderson style plug connections and their functions.
- Blue: Solar Input (+)
- Black: Ground (GND) for Solar Input
- Yellow: Output (+) to Auxiliary Battery
- Black: Ground (GND) for Output
- Red: DC Input (+) from Start Battery
- Black: Ground (GND) for DC Input
- ACC Ignition Line: Connect to an ignition-switched power source (optional, for smart alternator compatibility).
5.2. Wiring Diagram
Follow the wiring diagram for a typical installation in a vehicle with both a start battery and an auxiliary (house) battery, including an optional solar panel connection.
Image 5.2: Comprehensive wiring diagram for installation.
Important Considerations:
- Ensure appropriate fuses/breakers are installed on all positive lines as indicated in the diagram.
- The ACC ignition wire is recommended for vehicles with smart alternators to ensure proper charging initiation.
- Maintain proper cable gauge for the current draw to prevent voltage drop and overheating.
6. Operating Instructions
6.1. Battery Type Selection
Press the "SELECT" button on the charger to cycle through and choose the appropriate battery type for your auxiliary battery (AGM, Gel, Calcium, Lead Acid, or LiFePO4). The selected battery type will be indicated by an illuminated LED.
6.2. Reverse Charging Function
To activate reverse charging and revive a flat start battery from your auxiliary battery, press the "REVERSE CHARGE" button. This feature ensures your starter battery remains charged for off-road use.
Image 6.1: Location of the Reverse Charge button.
6.3. DC Charging Priority
The charger is configured with DC charging priority. When both the vehicle's start battery (DC input) and solar panels are connected and meet the startup conditions, the charger will prioritize the vehicle battery input. If solar charging is already active, the system will continuously monitor the DC input and automatically switch to DC power if conditions are met.
- Startup Conditions:
- DC Input: 13-24V
- Solar Input: 13-26V
Image 6.2: DC Charging Priority logic.
6.4. LiON Mode for LiFePO4 Batteries
For LiFePO4 batteries, the intelligent LiON mode automatically activates a sleeping battery, ensuring prolonged and reliable use without manual intervention.
Image 6.3: The charger's LiON mode activating a LiFePO4 battery.
7. Maintenance
Regular maintenance ensures the longevity and optimal performance of your charger:
- Periodically inspect all wiring and connections for signs of wear, corrosion, or looseness.
- Keep the charger clean and free from dust and debris. Use a dry cloth for cleaning.
- Ensure adequate ventilation around the unit to prevent heat buildup.
- Check the condition of fuses/breakers regularly and replace if necessary with the correct rating.
8. Troubleshooting
If you encounter issues with your charger, refer to the following common troubleshooting steps:
- Charger Not Activating:
- Verify that both DC input (from start battery) and/or solar input meet the minimum voltage requirements (DC: 13-24V, Solar: 13-26V).
- Check all connections for proper seating and polarity.
- Inspect fuses/breakers for continuity.
- Ensure the ACC ignition wire (if used) is receiving power when the vehicle is running.
- Low Charging Output:
- Confirm the correct battery type is selected on the charger.
- Check for excessive voltage drop in wiring due to undersized cables or long runs.
- Ensure solar panels are clean and receiving adequate sunlight if solar charging is active.
- Verify the alternator is functioning correctly and providing sufficient voltage.
- Overheating:
- Ensure the charger is installed in a location with sufficient airflow.
- Remove any obstructions around the cooling fins.
- Reduce load if possible, or ensure the charger is not operating beyond its rated capacity.
If the issue persists after performing these checks, contact ATEM POWER customer support.
9. Specifications
| Feature | Specification |
|---|---|
| Model | 40A DC to DC Battery Charger |
| Product Dimensions | 5.59"D x 7.48"W x 1.97"H (14.2cm D x 19cm W x 5cm H) |
| Item Weight | 3.19 pounds (1.45 kg) |
| Output Voltage | 12 Volts (DC) (Note: Input voltage range is 13-24V for DC, 13-26V for Solar) |
| Battery Compatibility | AGM, Gel, Calcium, Lead Acid, LiFePO4 |
| Manufacturer | ATEM POWER |
| Color | Gray |
Image 9.1: Product dimensions.
10. Warranty and Support
The ATEM POWER 40A DC to DC Battery Charger comes with a 1-year warranty from the date of purchase, covering defects in materials and workmanship.
For technical support, warranty claims, or further assistance, please contact ATEM POWER customer service through their official website or the retailer where the product was purchased. Please have your purchase receipt and product model information ready.
