Project Description

20A DC-DC Charger with Bluetooth Screen

Compact in size and easy to install, the new Thunder DC-DC Charger is the smart way to charge your auxiliary battery, no matter your vehicle. Utilising a unique pulse charging algorithm with the intelligence to determine the best charge rate for your auxiliary battery, this charger is the perfect addition to any vehicle requiring the management of a dual battery setup.

One of the greatest features of the new DC-DC Battery Charger, is the new remote Bluetooth LCD screen; giving you better visibility on your battery’s state of charge. The new charger also features Modular Sense Technology (MST) allowing you to link multiple units together giving you a 20, 40 or 60A output without having to outlay for a larger unit upfront.

Suitable for Gel, AGM, Calcium, Lead Acid and now Lithium batteries, Thunder’s new DC-DC Charger is an ideal addition for caravans, camper trailers and 4WD’s.

  • Sleek new heavy duty aluminium case
  • Easy to read remote mount Bluetooth LCD screen
  • 12-24V System input with 12V output
  • Upgraded operating temperature of 0-90° allowing under bonnet mounting
  • IP67 Rated – water and dust proof, ready for harsh environments
  • New linkable design to easily increase amperage outputs using Modular Sense Technology
  • Microchip monitoring and control fully automates high frequency multistage charging
  • Pulse mode technology that reduces oxidation and minimises temperature equating to longer battery life
  • Unit will automatically change charge rate mapping for GEL, AGM and standard Lead Acid
  • New Lithium battery charging profile option
  • Internal charger temperature monitoring and power output control
  • Over charging, short circuit and over temperature protection
  • Reverse polarity protection
  • New 50V solar input with MPPT regulated output allowing 300W of solar

Click here for the Product Manual

Part Number: TDR02021

RRP: $499


Output: 20A
Input Fuse Rating Minimum: 30A
Output Fuse Rating Minimum: 30A
Vehicle Input Voltage Range: 12.2V – 26V *(If voltage increases over 26V the Thunder DC-DC will shut off, reset will be needed)
Minimum/Maximum Charging Voltages: 13.1V – 15.2V (stops charging when alternator or vehicle battery below 12.2V)
Solar Input Voltage Range: 13V-50V
Maximum Solar Watt Input: 300W *(exceeding 300W of Solar will damage the Thunder DC-DC charger)

Charging Style: 8 stage from vehicle and 3 stage from solar
Operating Temperature: 0°C to 90°C (current de-rates after 90°)
IP Rating: IP67
Float Voltage: 13.8V
Standby Current: 10mA
Battery Range: 18 to 250Ah
Dimensions (LxWxH): Charger: 190x125x35mm / Display: 75x75x20mm

Integrated Bluetooth LCD Screen

The remote LCD interface screen gives you better visibility on your battery’s state of charge, without looking directly at the unit. This design, its IP67 rating and 90°C operating temperature means the charger can be installed in an engine bay with a reduced likelihood of it de-rating due to the harsh under bonnet environment, with the display in the cabin.

While your vehicle is charging, the LCD screen will show the Vehicle Car Charge screen, allowing you to see the main and auxiliary battery voltages, auxiliary battery percentage and how much current is flowing into the battery. It will also show if Lithium mode is being used.

After the vehicle’s engine has been turned off and the battery voltage in the main battery has reached a loaded voltage of 12.2V, the LCD screen will move to the Solar Charge screen showing battery voltages, percentages and the flow of the solar charge.


  • Clear visual display of state of charge of all batteries
  • IP67 rating and 90°C operating temperature means the charger can be installed in an engine bay with a reduced likelihood of it de-rating due to the harsh under bonnet environment
  • Easily identify and rectify battery faults
  • Easily identify if your batteries are charged by the alternator or solar

View the full range of products in the Complete Range Collection.

The range includes LED Lighting, 4×4 Accessories, 4×4 Lifestyle products, Fridges, Battery Chargers, DCDC Chargers, Switches, Gauges, Switch Panels and more