Renogy Dual Input DC-DC On Board Battery Charger w/ MPPT

Important Safety Instructions

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This manual contains important safety, installation, and operating instructions for the DCDC Battery Charger. Do not operate the Battery Charger unless you have read and understood this manual and the charger is installed as per these installation instructions. Renogy recommends that the charger be installed by a qualified professional. Store it in a safe place. The following symbols are used throughout the manual to indicate potentially dangerous conditions or important safety information:

• DANGER: Safety instruction: Failure to observe this instruction will result in fatal or serious injury.
• WARNING: Safety instruction: Failure to observe this instruction can result in fatal or serious injury.
• CAUTION: Safety instruction: Failure to observe this instruction can lead to injury.
• NOTICE: Failure to observe this instruction can cause material damage and impair the function of the product.
• NOTE: Supplementary information for operating the product.

The manufacturer accepts no liability for damage in the following cases:

• Faulty assembly or connection.
• Damage to the product resulting from mechanical influences and excess voltage.
• Alterations to the product without expressed permission from the manufacturer.
• Use for purposes other than those described in the operating manual.

For protection, pay close attention to the following basic safety information when using electrical services:

• Electric shock
• Fire hazards
• Injury

General Safety

DANGER: In the event of fire, use a fire extinguisher that is suitable for electrical devices.

WARNING:

• Only use the product as intended.
• Make sure all connections going into and from the product are tight.
• Disconnect the product from the battery each time before cleaning and maintenance, and before a fuse change (only by specialists).
• Do NOT allow water to enter the product. Detach all connections and make sure that no voltage is present on any of the inputs and outputs.
• The product may not be used if the product itself or the connection cable is visibly damaged.
• This product may only be repaired by qualified personnel. DO NOT disassemble or attempt to repair the unit. Inadequate repairs may cause serious hazards.
• Electrical devices are not toys. Always keep and use the product out of the reach of children.
• Children must be supervised to ensure that they do not play with the product.

NOTE:

• Before start-up, check that the voltage specification on the plate is the same as that of the power supply.
• Ensure that other objects cannot cause a short circuit to the contacts of the product.
• Store the product in a dry and cool place.

Safety when connecting the product electronically

DANGER: Danger of fatal electric shock!

• For installation on boats: If electrical devices are incorrectly installed on boats, this can lead to corrosion damage on the boat. Have the product installed by a qualified (boat) electrician.
• If you are working on electrical systems, ensure that there is somebody close at hand who can help you in emergencies.

WARNING:

• Make sure that the cables have a sufficient cross-section.
• Lay the cables so that they cannot be damaged by doors or the bonnet. Crushed cables can lead to serious injury.

CAUTION: Lay the cables so that they cannot be tripped over or damaged.

NOTICE:

• Use ductwork or cable ducts if it is necessary to lay cables through metal panels or other panels with sharp edges.
• Do not lay the AC cable and DC cable in the same conduit (empty pipe).
• Do not lay the cables so that they are loose or heavily kinked.
• Firmly secure the cables; ensure they do not contact each other.
• Do not pull on the cables.

Charger Safety

NOTICE:

• NEVER connect the solar panel to the charger without a service battery connection. The Battery must be connected first.
• Ensure the PV input voltage does not exceed 25 Vdc to prevent permanent damage. Use the Open Circuit Voltage (Voc) at the lowest temperature to make sure the voltage does not exceed this value when connecting panels together.

Battery Safety

WARNING: Batteries may contain aggressive and corrosive acids. Avoid battery fluid coming into contact with your body. If your skin does come into contact with battery fluid, thoroughly wash that part of your body with water. If you sustain any injuries from the acids, contact a doctor immediately.

CAUTION:

• When working on batteries, do not wear any metal objects such as watches or rings. Lead acid batteries can cause short circuits which can cause serious injuries.
• Danger of explosions! Never attempt to charge a frozen or defective battery. In this situation, place the battery in a frost-free area and wait until the battery has adjusted to the ambient temperature, then start the charging process.
• Wear goggles and protective clothing when you work on batteries. Do not touch your eyes when working with batteries.
• Do not smoke and ensure that no sparks can arise in the vicinity of the engine or battery.

NOTICE:

• Only use rechargeable batteries.
• Use sufficient cable cross sections.
• Protect the positive conduit with a fuse.
• Prevent any metal parts from falling on the battery. This can cause sparks or short circuit the battery and other electrical parts.
• Make sure the polarity is correct when connecting.
• Follow the instructions of the battery manufacturer and those of the manufacturer of the system or vehicle in which the battery is used.
• If you need to remove the battery, disconnect it first from the ground connection. Disconnect all connections from the battery before removing it.

General Information

The Renogy Dual Input DC-DC On Board Battery Charger w/ MPPT is designed to charge your service battery to 100% from two inputs: solar and alternator. Featuring multi-battery compatibility including Lithium, this DCDC utilizes alternator power, solar power with MPPT technology, or both to make sure that you're always charged and can enjoy being off the grid longer!

Key Features

• Designed to charge service batteries from two DC inputs—solar panels and alternator.
• Built-in Maximum Power Point Tracking (MPPT) to maximize the solar power.
• 3-phase charging profile (Bulk, Boost, and Float) ensures your service battery will be accurately charged at the correct voltage levels to 100%.
• Compatible with smart alternators (with variable output voltage).
• Trickle charges the starting battery via solar panels if the service battery is fully charged.
• Isolation of the starting battery and the service battery.
• Temperature and voltage compensation features prolong battery life and improve system performance.
• Smart Protection Features: battery isolation, over-voltage protection, battery temperature protection, over-current protection, overheat protection, reverse current protection, solar panel and alternator reverse polarity protection.
• Compatible with multiple battery types: Sealed, AGM, GEL, Flooded, and Lithium.
• Compact with a sturdy design, it was built tough for all conditions.

Product Overview

Identification of Parts

The DCDC charger features multiple input and output terminals, indicator LEDs, and a battery type selection button. The following lists the key parts:

• 1. PV+: Positive (+) input terminal for the PV Array. Requires ring terminal.
• 2. ALT+: Positive (+) input terminal from the Starter Battery.
• 3. OUT+: Positive (+) output terminal for House Battery.
• 4. NEG-: Common Negative (-) Terminal for Solar Panel Array, Starter Battery, and House Batt.
• 5. RS485: Communication port for app and monitoring screen; future development.
• 6. BTS: Battery Temperature Sensor port utilizing data for accurate temperature compensation and charge voltage adjustment.
• 7. BVS: Battery Voltage Sensor (RVSCC) port for measuring the battery voltage accurately with longer line runs. Due to connection and cable resistance, discrepancies in voltages at the terminal vs the BVS can occur.
• 8. IGN+: Ignition Signal Input port for triggering the battery charger for smart alternators. IGN wire recommended 18-16AWG. For Standard/Traditional Alternators, this port has a fixed voltage when charging (Do not connect IGN wire). For Smart Alternators, it has a controlled charging output based on operating conditions (Requires IGN signal wire).
• 9. TYPE: Battery type push button. Change the LED to match the battery type of your application.
• 10. Alternator/Charging Indicator: LED indicator.
• 11. Solar Charging Indicator: LED indicator.
• 12. Service Battery Indicator: LED indicator.
• 13. Battery Type Indicator: LED indicator.

Dimensions

The 30A/50A models share the same dimensions: 244mm (9.60in) length, 146mm (5.75in) width, and 77mm (3.03in) height. Mounting holes are spaced appropriately for secure installation.

Additional Components

Included Components

• Battery Temperature Sensor: Measures battery temperature for accurate temperature compensation and charge voltage adjustment. NOTE: No temperature compensation when charging lithium battery.
• IGN Signal Wire for Smart Alternator: Connects to the IGN port for smart alternators to control output voltage based on operating conditions. Recommended wire gauge is 18-16AWG. NOTE: Not connected if using a traditional alternator.
• RS485 Communication Cable: For app and monitoring screen connectivity; future development.

Optional Components

Optional components require a separate purchase.

• Battery Voltage Sensor (RVSCC): Provides more accurate battery charging by measuring voltage directly at the battery terminals, compensating for voltage drops over long cable runs.

Installation

Mount the Battery Charger

DANGER: Never mount the product in areas where there is a risk of gas or dust explosion.

CAUTION: Ensure a secure stand! The product must be set up and fastened in such a way that it cannot tip over or fall down.

NOTICE:

• Do not expose the product to any heat source (such as direct sunlight or heating). Avoid additional heating of the product.
• Set up the product in a dry location protected from splashing water.

Location Considerations

• The battery charger can be installed horizontally as well as vertically.
• The battery charger must be installed in a place that is protected from moisture.
• The battery charger may not be installed in the presence of flammable materials.
• The battery charger may not be installed in a dusty environment.
• The place of installation must be well ventilated. A ventilation system must be available for installations in small, enclosed spaces. The minimum clearance around the battery charger must be at least 5cm.
• The device must be installed on a level and sufficiently sturdy surface.

When selecting a location for the DCDC, ensure the unit is as close as possible to the battery you will be charging (auxiliary battery). Mounting options include the cabin of the vehicle, along a chassis rail, the inner guard of a vehicle, behind the grille or headlight, or even on the side of the radiator. Ensure the area is not susceptible to moisture or other substances, as well as potentially high temperatures. The DCDC operates best with some airflow.

Connecting Components

Connecting Temperature Sensor

The temperature sensor has a green housing connector on one end and a metal probe on the other. Align and connect the green housing to the BTS terminal on the DCDC. Place the probe end of the sensor near or on top of the battery to monitor temperature.

Connecting IGN Signal Wire

Connect the positive line to one of the green housing ports on the IGN port. Open the wire terminal using the screws on top of the green housing. Connect the positive line of the IGN to the ignition circuit. This is for smart alternators. For standard/traditional alternators, do not connect the IGN wire.

NOTE: There are two ports on the green IGN connector housing. Both ports have a positive polarity, so only one connection is required from either port.

Connecting Battery Voltage Sensor

Connect the Battery Voltage Sensor connector to the BVS port. Connect the positive line to the left side of the green housing and the negative line to the right side of the green housing. Open the wire terminal using the screws on top of the green housing. Place the bare wire end onto the respective battery terminal for accurate voltage sensing.

Selecting the Battery Type

To change the battery type, press the push button located on the PV+ and ALT+ side of the DCDC. The following chart indicates the Battery Type LED status.

NOTE: User mode is an extra feature accessed via App or Monitoring Screen; Future Development.

Connect the Battery Charger

WARNING: Do not reverse the polarity. Reverse polarity of the battery connections can cause injury and damage the device.

CAUTION:

• Avoid coming into contact with battery fluid under any circumstances.
• Batteries with a cell short circuit should not be charged as explosive gases may form due to battery overheating.
• Be careful not to over-torque the terminals on the DCDC. Over-torquing may cause irreparable damage. Do not exceed 16 N-m / 3.3 ft-lb.

NOTE:

• Make sure the battery poles are clean when connecting the terminals.
• Select a sufficient cross-section for the connection cable.
• Use the following cable colors: Red: positive connection, Black: negative connection.
• Tighten the nuts and bolts with proper torque. Loose connections may cause overheating.

For safety, always connect ground (NEG.-) first, then connect the service battery positive, starting battery positive, and PV positive respectively.

1. Connect a negative power cable to the (NEG. -) terminal on the DCDC, and connect the other end to the negative pole of the service battery or directly to the chassis.
2. Connect a positive power cable between the (OUT+) terminal on the DCDC and the positive pole of the service battery.
3. Connect a positive power cable between the (ALT+) terminal on the DCDC and the positive pole of the starting battery.
4. Optional (for system setup with Smart Alternator): Connect the IGN Signal Wire between the Ignition Signal Input port on the DCDC and the vehicle ignition.
5. Connect a cable between terminals marked PV+ on the DCDC to the PV positive.

Typical Setup

The typical setup involves connecting a solar panel array to the PV+ and NEG- terminals, the starter battery to the ALT+ and NEG- terminals, and the house battery (service battery) to the OUT+ and NEG- terminals. An ANL fuse is recommended for the starter and house batteries. The IGN signal wire connects the alternator to the IGN+ port for smart alternators. A MC-4 inline fuse is used for the solar panel connection.

NOTE: Be careful not to over-torque the terminals on the DCDC. Over-torquing may cause irreparable damage. Do not exceed 16 N-m / 3.3 ft-lb.

Cable and Fuse Sizing

Fusing

Cable sizing

Operation

LED Indicators

Solar Charging Indicator

Service Battery Indicator

NOTE: The Charging Indicator may change under the following conditions:

• Red to Yellow: When the voltage reaches 12.2V under voltage recovery.
• Yellow to Red: When the voltage drops to 12.0V under voltage warning.
• Yellow to Green: A. When it reaches constant voltage charging state, the charging current is smaller than 3A, lasts for 30 seconds; B. When the charging current is higher than 3A, it keeps charging until it reaches constant voltage state and the current drops below 3A, lasts 30 seconds.

Alternator/Charging Indicator

Battery Type Indicator

NOTE: User mode is an extra feature accessed via App or Monitoring Screen; Future Development.

Charging Logic

Alternator Input

1. Connect alternator with starting battery and service battery (No solar panel, or night time):

1.1 The DCDC battery charger will connect or disconnect the service battery according to the starting battery voltage.

1.2 The DCDC will stop charging if the alternator input voltage is higher than 16.5V, and recover to charge when the voltage is lower than 15.5V.

1.3 The maximum alternator charging for the DCDC30 is 30A and the DCDC50 is 50A.

Solar Panel Input

2. Connect solar panel, starting battery and service battery (Engine not running):

2.1 The solar input charges the service battery as priority. If the service battery voltage is lower than the boost voltage setting, solar panel will only charge the service battery.

2.2 If the service battery is in float charge stage, the starting battery will be charged at the same time. The charging voltage is limited at 13.8V. The charging amperage is limited at 25A.

2.3 After charging the starting battery for 1 minute, it will disconnect for 30 seconds and check the starting battery voltage. It will continue to charge starting battery if the voltage is lower than 12.7V and will stop charging if the voltage is higher than 13.2V.

2.4 Solar charging will be triggered if the PV input voltage is higher than 15V for 10 seconds.

2.5 The DCDC will stop charging if the PV input voltage is higher than 25.5V, and recover to charge when the voltage is lower than 24.5V.

2.6 The maximum solar charging for the DCDC30 is 30A and the DCDC50 is 50A.

Dual Input (Alternator/Solar)

3. Connect solar panel, alternator with starting battery and service battery:

3.1 The DCDC will always take as much power from the solar panel as it can before supplementing that power from alternator input, up to the rated charging current.

3.2 If the solar input power is able to keep the service battery at constant voltage charge stage, alternator wouldn't charge the service battery.

3.3 If the MPPT charging current from solar input is not able to keep the service battery at constant voltage charge stage, alternator will cut in to charge the service battery. In this case, the maximum dual input charging will be limited to 50% from each source.

a. DCDC30: 15A from alternator, up to 15A from solar for a total of up to 30A.

b. DCDC50: 25A from alternator, up to 25A from solar for a total of up to 50A.

Operating Temperature

4.1 The DCDC will lower the output power when its internal temperature is in the range from 65°C to 80°C. It will stop charging when the temperature is higher than 80°C, and recover to charge when the temperature is lower than 60°C.

4.2 If the service battery type is set to lead-acid, the DCDC will stop charging the service battery when its temperature is lower than -36°C, and recover to charge when it's higher than -34°C.

4.3 If the service battery type is set to lithium, the DCDC will stop charging the service battery when its temperature is lower than 1°C, and recover to charge when it's higher than 3°C.

Solar Charge Algorithm

MPPT Technology

The DCDC utilizes Maximum Power Point Tracking technology to extract maximum power from the solar module(s). The tracking algorithm is fully automatic and does not require user adjustment. MPPT technology tracks the array's maximum power point voltage (Vmp) as it varies with weather conditions, ensuring that the maximum power is harvested from the array throughout the course of the day.

Current Boost

In many cases, the MPPT charger will "boost" the current in the solar system. The power generated in the solar panels is the same power that is transmitted into the battery bank. Power = Voltage (V) x Amperage (A). Therefore, assuming 100% efficiency:

Power In = Power Out

Volts In * Amps In = Volts out * Amps out

Although MPPT chargers are not 100% efficient (typically 92-95%), when the Vmp of the solar system is greater than the battery bank voltage, the potential difference is proportional to the current boost. The voltage generated at the solar module is stepped down, and the amperage is boosted accordingly. This means a charger can send more amps to the battery bank than it receives in amps from the solar panel, which is the advantage of MPPT chargers over traditional chargers where stepped-down voltage is wasted as heat.

Limiting Effectiveness

Environmental temperature increases reduce the operating voltage (Vmp) and limit power generation of the solar module. Despite MPPT technology, performance may decrease. Modules with higher nominal voltage are preferred in such scenarios so that despite the panel's performance drop, the battery still receives a current boost due to the proportional drop in module voltage.

Four Charging Stages

The DCDC MPPT charge controller uses a 4-stage battery charging algorithm: Bulk Charge, Boost Charge, Float Charge, and Equalization.

Charging Stage Diagrams:

• Battery Voltage: Shows stages A (Bulk Charge), B (Constant charging), C (Float Charge), with transitions for Equalize, Boost, Float, and Recharge.
• Battery Current: Shows Max Current, Duration Time (10-180min), Cumulative Time (3h), and stages for Bulk, Boost.

Bulk Charge: Used for day-to-day charging, utilizing 100% of available solar power. Operates in constant current mode, delivering maximum current to the batteries.

Constant Charging: When the battery reaches the constant voltage set point, the charger operates in constant charging mode (no longer MPPT). Current drops gradually. This includes equalize and boost stages, not carried out constantly to avoid gas precipitation or overheating.

Boost Charge: Maintains a charge for 2 hours by default.

Float Charge: After the constant voltage stage, the charger reduces battery voltage to a float set point. This lightly charges the battery to offset power consumption and maintain storage capacity. If load exceeds charge current, float stage ends and reverts to bulk charging.

Equalization: Carried out every 28 days for a controlled period of intentional overcharging. Benefits certain battery types by stirring electrolyte, balancing voltage, and completing chemical reactions. Increases battery voltage, which gasifies the battery electrolyte.

WARNING: Over-charging and excessive gas precipitation may damage battery plates and activate material shedding. Too high or prolonged equalizing charge can cause damage. Review specific battery requirements.

Lithium Battery Activation

The charger has a feature to awaken a sleeping lithium battery. If a lithium battery is over-discharged, its protection circuit turns it off. This feature applies a small charge current to activate the protection circuit and initiate a normal charge if a correct cell voltage is reached.

Troubleshooting

CAUTION: Do not open the device. You risk exposing yourself to an electric shock.

NOTE: For detailed questions, contact Renogy customer support.

Solar Charging Indicator

Service Battery Indicator

Alternator Indicator

Technical Specification

Battery Charging Parameters

NOTE: User mode is an extra feature accessed via App or Monitoring Screen; Future Development.

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:

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

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, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Contact Information

Renogy reserves the right to change the contents of this manual without notice.

United States (US)

2775 E Philadelphia St, Ontario, CA 91761, USA

Phone: 909-287-7111

Website: www.renogy.com

Email: support@renogy.com

China (CN)

苏州高新区科技城培源路1号5号楼-4

Phone: 400-6636-695

Website: https://www.renogy.cn

Email: support@renogy.cn

Japan (JP)

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Email: supportjp@renogy.com

Canada (CA)

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Email: supportca@renogy.com

Australia (AU)

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Email: supportau@renogy.com

United Kingdom (UK)

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Email: supportuk@renogy.com

Germany (DE)

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Email: supportde@renogy.com