Renogy DC-DC Battery Charger

Before Getting Started

This quick guide provides important operation and maintenance instructions for the Renogy 12V 20A/40A DC-DC Battery Charger (referred to as the battery charger). Read this guide carefully before operation and save it for future reference. Failure to observe the instructions or precautions can result in electrical shock, serious injury, death, or damage to the battery charger.

Online Manuals: Access the full Quick Guide and User Manual by scanning the QR codes provided in the original document.

What's In the Box?

Ensure all accessories are complete and free of damage. The following items are included:

• Renogy 12V 20A/40A DC-DC Battery Charger × 1
• Quick Guide × 1
• Mounting Screws (ST4*16 mm) × 4
• Battery Temperature Sensor (2 m) × 1
• IGN Signal Wire (3 m) × 1

Note: Package contents may vary depending on the specific product model.

Dimensions

20A DC-DC Battery Charger (RBC20D1U):

• Height: 2.75 in (70 mm)
• Width: 8.56 in (217.5 mm)
• Depth: 9.31 in (236.5 mm)
• Unit Depth: 5.17 in (131.5 mm)

40A DC-DC Battery Charger (RBC40D1U):

• Height: 3.56 in (90.5 mm)
• Width: 8.56 in (217.5 mm)
• Depth: 9.31 in (236.5 mm)
• Unit Depth: 6.00 in (152.5 mm)

Dimension tolerance: ±0.2 in (0.5 mm)

Get to Know Renogy Battery Charger

The Renogy DC-DC Battery Charger features several key components:

• Indicators: Battery Type Indicator, Fault Status Indicator, Battery Status Indicator.
• Controls: Battery Type Setting Button.
• Terminals: Positive Output Terminal, Negative Output Terminal.
• Ports: RS485 Communication Port, Battery Temperature Sensor (BTS) port.
• Mounting: Mounting Holes are available for secure installation.

Diagram shows the top and side views of the battery charger with labels pointing to the indicators, button, terminals, and ports.

Input Terminals and Ports

The battery charger has input terminals for connecting to the vehicle's electrical system:

• Positive Input Terminal (ALT +)
• Negative Input Terminal (ALT -)
• IGN Signal Wire Port: For connecting the ignition signal wire.
• Mounting Holes

Important: The Battery Temperature Sensor (BTS) port can only be used with lead-acid batteries.

Diagram shows the input side of the battery charger, highlighting the ALT+ and ALT- terminals, IGN Signal Wire Port, and mounting holes.

System Setup

This section illustrates the wiring connections for system setup. Wire colors indicate function:

• Red: Positive
• Black: Negative
• Purple: Temperature (BTS)
• Cyan: Communication (RS485)
• Blue: IGN Signal

The diagram shows the battery charger connected to a Starter Battery, a Smart DC Alternator, and a 12V Auxiliary Battery. A Renogy BT-2 Bluetooth Module is also shown connected for monitoring.

Wiring diagram illustrating the connections between the DC-DC battery charger, starter battery, smart DC alternator, auxiliary battery, and Bluetooth module.

Required Tools

Before installation and configuration, gather the following tools:

• ? Phillips Screwdriver (#1)
• ? Insulating Gloves
• ? Measuring Tape
• Insulation Tape

Note: Always prepare recommended tools, components, and accessories prior to installation.

Step 1. Wear Insulating Gloves

Always wear insulating gloves during installation and operation for safety.

Illustration shows a hand wearing insulating gloves near the battery charger.

Step 2. Plan a Mounting Site

The battery charger requires adequate clearance for installation, wiring, and ventilation. Minimum clearance is 5.91 inches (150 mm) on all sides.

Environmental considerations:

• Temperature Range: -40°F to 185°F (-40°C to 85°C)
• Humidity: 0% to 95%
• Conditions: [Keep Dry], [Fragile], [Ventilation], [Indoor]

The battery charger should be installed on a flat surface protected from direct sunlight.

Diagram shows the required clearance around the battery charger and icons representing environmental conditions.

Step 3. Connect the Battery Charger to an Auxiliary Battery

The battery charger is compatible with deep-cycle GEL, Flooded Lead-Acid (FLD), Sealed Lead-Acid (SLD/AGM), and Lithium Iron Phosphate (LI) batteries.

Recommended Components & Accessories:

• 12V Battery: (9V to 16V range)
• Fuse: *ANL Fuse × 1 (RBC20D1U: 30A, RBC40D1U: 40A)
• Cables: Battery Adapter Cables × 2 (RBC20D1U: 10 AWG, RBC40D1U: 8 AWG)
• Fuse Cable: × 1 (RBC20D1U: 10 AWG, RBC40D1U: 8 AWG)

Accessories marked with "*" are available on renogy.com.

Installation Steps:

1. Install cables on the battery charger: Connect the M5 terminals for BAT- and BAT+.
2. Install an ANL fuse: Connect the fuse in line with the positive cable.
3. Install the cables on the battery: Connect the negative cable to the negative terminal and the positive cable (with fuse) to the positive terminal of the auxiliary battery.

For optimal performance, use cables no longer than 3 meters (10 AWG/8 AWG). For longer distances, choose higher gauge cables. Refer to the user manual for details.

Diagrams illustrate connecting cables to the charger, installing the ANL fuse, and connecting to the auxiliary battery terminals.

Step 4. Connect the Battery Charger to a Starter Battery

Consult your vehicle's user manual or manufacturer to ensure alternator power does not exceed 720W with output current between 75A to 100A.

Recommended Components & Accessories:

• Fuse: *ANL Fuse × 1 (RBC20D1U: 40A, RBC40D1U: 80A)
• Cables: Battery Adapter Cables × 2 (RBC20D1U: 8 AWG, RBC40D1U: 6 AWG)
• Fuse Cable: × 1 (RBC20D1U: 8 AWG, RBC40D1U: 6 AWG)

Accessories marked with "*" are available on renogy.com.

Connection Types:

• Traditional DC Alternator (IGN connection not required): Charging starts at 13.5V, stops at 11.5V.
• Smart DC Alternator (IGN connection required): Charging starts at 12.6V, stops at 11V.

Diagrams illustrate connecting cables to the charger, installing the ANL fuse, and connecting to the RV starter battery terminals.

Step 5. Install a IGN Signal Wire (for Smart DC Alternator)

IGN signal wiring is required only for smart alternators. If your vehicle has a smart DC alternator, connect the IGN Signal Wire connector to the IGN signal wire port on the charger and the other end to the smart alternator's ignition signal port.

Consult your RV supplier for specific wiring details.

Diagram shows the IGN signal wire connecting from the smart DC alternator to the IGN signal wire port on the battery charger.

Step 6. Install a Battery Temperature Sensor

The temperature sensor measures ambient battery temperature to compensate floating charge voltage, especially at low temperatures.

Important: Do not use the temperature sensor on LiFePO4 (LFP) batteries with a Battery Management System (BMS).

Mount the sensor securely in close proximity to the battery.

Diagram shows the Battery Temperature Sensor mounted near a battery and connected to the BTS port on the battery charger.

LED Indicators

The battery charger has LED indicators to show its operating status:

Battery Status Indicator:

• Solid: Charger is in standby mode* or auxiliary battery is fully charged.
• Flash: Charging the auxiliary battery.

Fault Status Indicator:

• Off: No fault.
• Solid: Short-circuit protection (auxiliary or starter battery).
• Slow flash: Reverse contact protection (starter battery).
• Solid: Overtemperature protection (auxiliary battery).
• Slow flash: Overtemperature protection (battery charger).
• Fast flash: Overvoltage protection (auxiliary battery).
• Jumping flash: Overdischarge shutdown protection (auxiliary battery).

Battery Type Indicator:

• Solid: SLD/AGM
• Solid: GEL
• Solid: LI (lithium battery activation disabled)
• Solid: LI (lithium battery activation enabled)
• Solid: User Mode
• Solid: FLD

Standby Mode*: Charger is connected only to the auxiliary battery, and its voltage is greater than 12V.

Diagram shows the charger's indicator lights labeled Battery, Fault, and Type, with lines pointing to descriptions of their states.

LED Patterns Explained

This section details the graphic expressions of LED patterns:

Set a Battery Type

After installing the battery charger, set the correct battery type using the Battery Type Setting Button.

Crucial: Incorrect battery type settings can damage the charger and void the warranty.

Available Battery Types:

• SLD/AGM (Sealed Lead Acid Battery)
• GEL (Gel Battery)
• LI (Lithium battery, activation disabled)
• LI (Lithium battery, activation enabled)
• FLD (Flooded Battery)
• User Mode (Custom Battery)

Diagram illustrates the flow for selecting battery types (SLD/AGM, GEL, LI, FLD, User Mode) using the setting button and indicator lights.

USER Mode

Setting the battery type to User Mode allows customization of battery parameters via the DC Home app.

Illustration shows the "Type" button being pressed on the charger, leading to a smartphone screen displaying the DC Home app interface with customizable battery parameters (Battery Type, House Battery Volts, Starter Battery Volts, Starter Battery Amps, House Battery Charging Amps).

When customizing settings, consult the battery manufacturer's user manual. Contact the manufacturer for further assistance if needed.

For detailed parameter settings, see the user manual of the battery charger at renogy.com/support/downloads.

Monitor the Battery Charger

Monitor and manage your battery charger using the Renogy BT-2 Bluetooth Module and the DC Home app.

Recommended Components:

• *Renogy BT-2 Bluetooth Module

Accessories marked with "*" are available on renogy.com.

Ensure the DC Home app and Renogy ONE firmware are updated to the latest versions before adding the product.

Charging current can be customized through the DC Home app.

Diagram shows the Renogy BT-2 Bluetooth Module connected to the battery charger's RS485 port, with wireless signals indicating connection to a smartphone.

Download the DC Home App

Download the DC Home app and log in with your account to monitor and manage your battery charger.

Available on:

• Google Play
• App Store

Illustrations show the Renogy ONE app interface on a smartphone and QR codes for downloading the app.

App illustrations are for reference; follow instructions based on the current app version.

Keep your phone or Renogy ONE within 10 feet (3 m) of the battery charger for optimal performance.

Fault alarms can be received via DC Home and Renogy ONE. Log in to the app for troubleshooting details.

Short-Range Monitoring via DC Home App

Pair the battery charger with the DC Home app to monitor and modify its parameters.

Screenshots show the process of pairing the DC-DC charger with the DC Home app via Bluetooth, including searching for devices and confirming connection.

The diagram shows the battery charger, Renogy BT-2 Bluetooth Module, and smartphone displaying the app interface.

Wireless Long-Range Monitoring

Enable long-range monitoring using the Renogy ONE Core, which connects to the internet and communicates wirelessly with the battery charger (via BT-2 module).

Diagram illustrates the setup for long-range monitoring: battery charger connected to BT-2 module, BT-2 module communicating wirelessly with Renogy ONE Core, Renogy ONE Core connecting to the Internet, and a smartphone accessing data remotely.

Recommended Components:

• *RENOGY ONE Core
• *Renogy BT-2 Bluetooth Module

Important Safety Instructions

General Safety:

• Wear protective equipment and use insulated tools.
• Avoid jewelry or metal objects near the charger.
• Keep out of reach of children.
• Dispose of according to local regulations; use recycling channels.
• In case of fire, use FM-200 or CO₂ extinguisher.
• Improper installation on a boat may cause damage; use a qualified electrician.
• Do not expose to flammable or harsh chemicals/vapors.
• Clean regularly.
• Do not puncture, drop, crush, shake, strike, or step on the charger.
• Do not open, disassemble, repair, or tamper with the charger.
• Connect negative terminal before positive terminal.
• Cable length should not exceed 10 meters to avoid voltage drop.
• Cable specifications account for critical voltage drop (<3%) and may not suit all configurations.

Battery Charger Safety:

• Install on a vertical surface, protected from sunlight, high temperatures, and water. Ensure good ventilation.
• Keep away from heating equipment.
• Do not insert foreign objects.
• Confirm polarities before connection; reverse polarity can damage the charger and void the warranty.
• Do not touch connector contacts during operation.
• Disconnect all connectors before maintenance or cleaning.

Battery Safety:

• Do not use damaged batteries.
• Avoid contact with exposed electrolyte or powder if a battery is damaged.
• Risk of explosion! Never install in a sealed enclosure with flooded batteries or in confined areas where gases can accumulate.
• Ensure all battery groups are installed properly before installing the charger.

Renogy Support

For inaccuracies or omissions in this guide, visit or contact:

• Support & Downloads: renogy.com/support/downloads
• Email: contentservice@renogy.com

For more on solar systems, visit the Renogy Learning Center:

• renogy.com/learning-center

A questionnaire investigation QR code is available in the original document.

Technical Support

In the U.S.:

• Website: renogy.com/contact-us
• Phone: 1(909)2877111

Outside the U.S.:

• Canada: ca.renogy.com
• Australia: au.renogy.com
• South Korea: kr.renogy.com
• United Kingdom: uk.renogy.com
• China: www.renogy.cn
• Japan: jp.renogy.com
• Germany: de.renogy.com
• Other Europe: eu.renogy.com

FCC Statement

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

• (1) This device may not cause harmful interference.
• (2) This device must accept any interference received, including interference that may cause undesired operation.

Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

1. Reorient or relocate the receiving antenna.
2. Increase the separation between the equipment and receiver.
3. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
4. Consult the dealer or an experienced radio/TV technician for help.

FCC Radiation Exposure Statement

This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with a minimum distance of 20cm between the radiator and your body.

Disclaimer

Renogy 12V 20A/40A DC-DC Battery Charger Quick Guide © 2024 Renogy. All rights reserved.

RENOGY and ® are registered trademarks of Renogy.

• All information in the quick guide is subject to copyright and other intellectual property rights of Renogy and its licensors. The quick guide may not be modified, reproduced, or copied, in whole or in part, without prior written permission from Renogy and its licensors.
• The registered trademarks in the quick guide are the property of Renogy. Unauthorized use of the trademarks is strictly prohibited.
• Renogy ensures the accuracy, sufficiency, and applicability of information in the quick guide at the time of printing, due to continual product improvements that may occur.
• Renogy assumes no responsibility or liability for personal and property losses, whether directly or indirectly, caused by the user's failure to install and use the product in compliance with the quick guide.
• Renogy is not responsible or liable for any failure, damage, or injury resulting from repair attempts by unqualified personnel, improper installation, and unsuitable operation.
• The illustrations in the quick guide are for demonstration purposes only. Details may appear slightly different depending on product revision and market region.
• Renogy reserves the right to change the information in the quick guide without notice. For the latest quick guide, visit renogy.com.

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Manufacturer Information:

RENOGY New Energy Co.,Ltd
Address: No.66, East Ningbo Road Room 624-625 Taicang German Overseas Students Pioneer Park JiangSu 215000 CN

EC REP: eVatmaster Consulting GmbH, Battinastr. 30, 60325 Frankfurt am Main, Germany, contact@evatmaster.com

UK REP: EVATOST CONSULTING LTD, Office 101 32 Threadneedle Street, London, United Kingdom, EC2R 8AY, contact@evatost.com

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