40A 12V DC to DC On-Board Battery Charger

40A 12V DC to DC On-Board Battery Charger
starts- reviews
SKU: RNG-DCC1212-40-CA
CAD $199.99
Temperature Sensor *


CA stock, usually ships in 1 to 3 business days.



The DC-DC Battery Chargers are the most effective way to charge your house batteries from the starter battery. Compatible with a multitude of alternator types, the DC-DC battery charger offers correct charging for AGM, Flooded, Gel, and even Lithium deep cycle batteries! Featuring a 3-stage battery charger and multiple electronic protections, users can feel confident that their batteries are being charged optimally and automatically. For additional safety, it isolates the input from the output preventing incorrect voltage transmission. Easily install the compact yet sturdy DC-DC battery charger on RV's, commercial vehicles, boats, yachts, and many more applications!

If you have any questions regarding this product, please submit a case.

Key Features

  • Compatible Multiple Battery TypesCompatible with a multitude of alternator types, the DC-DC battery charger offers correct charging for AGM, Flooded, Gel, and Lithium batteries.
  • Smart 3-stage ChargingThe DC-DC battery charger will charge your house batteries from the starter battery by 3-stage charging (Bulk, Boost, and Float), to make sure it optimally and automatically charge to 100%.
  • Various Protections For Ultra SafetyOffers Over-voltage Protection, Over-temperature Protection, and Reverse Polarity Protection to ensure the operation safety. It also isolates the input and output to prevent voltage transmission errors and interfere with house battery charging.
  • Protect Your Starter BatteryThe DC-DC battery charger is capable of identifying whether the generator is started, to prevent over-discharge of the starting battery and protect the generator.
  • Reliable QualityThe compact and robust design makes it suitable for all conditions. CE certification.

If you want to learn more, please watch the videos below:

1. RV Alternator Smart DC to Dc Charging

Package Includes

Renogy 40A DC to DC Battery Charger

Renogy 40A DC to DC Battery Charger

1 x

Option:Battery Temperature Sensor 

Battery Temperature Sensor for DC TO DC On-board Battery Charger

1 x

Renogy 40A DC to DC Battery Charger  
Nominal Voltage: 12V Float Voltage: 13.2-13.8v
Rated Charge Current: 40A Boost Voltage: 14.1-14.7v
Output: 500W Operating Temperature: -20°C to +50°C
Idle Power Consumption: <0.4A Dimensions: 10.28 x 6.88 x 2.68 inches
Input Voltage Range: 8V-16V Weight: 4.14lbs
Equalization Voltage: N/A Certifications:CE, ROHS

Warranty Information

Accessories 1-year material warranty


1.What is a DC-DC charger? What is its purpose?
The DC-DC battery charger is installed between the starter battery and the house battery. For the RV system, The generator ensures stable power supply to the starter battery, and uses the extra power of the starter battery to supply power to the house battery.
2. How to choose a suitable battery charger?
1. Make sure that the entire system is a 12V system
2. Ensure that the maximum charging current provided by the DC-DC battery charger does not exceed the maximum charging current allowed by the house battery.
3. How to set the charging voltage value of the charger?
The DC-DC battery charger adopts the design of the DIP switch and it provides 6 charging voltage settings through five gears. These six charging voltages meet the requirements of lithium batteries and lead-acid batteries in order to provide more charging options. SW5 switch is the selection switch for switching between lead-acid batteries and lithium batteries.
4. What is the D+ Ignition cable? Is it necessary to connect?
The D+ Ignition cable is a design method used to identify whether the generator is started. This design method can well prevent the starting battery from being over-discharged during the charging process. When the generator is started, a signal will be obtained on the D+ Ignition cable, which will light up the indicator light of the charger.
Notes :The DC-DC will not power on or operate until the D+ ignition cable is connected.
5. How can I get these cables?
The battery temperature sensor for DC-to-DC car battery chargers can be purchased at the Renogy store. The D+ ignition cable can be purchased at the local store or online, it suits both D+ and LC terminals. 18-16AWG copper cable recommended.
More questions about your off-grid power system? Learn more from Renogy Learning Center!
Renogy DC-DC Battery Charger Manual

Review Hide Reviews

DC -DC charger

Benoit Letourneau on Sep 7th 2022

I recently installed this charger. It is fairly easy to install. The most difficult thing is to run the wires through the vehicle (but that as nothing to do with the charger itself). Once everything in place, you turn on the key and boom, it starts charger as advertised. For the price, I think this is a GREAT charger.