Redarc DCDC In-Vehicle Battery Charger
Redarc DCDC in-vehicle battery charger in our 4WD 12V electrical setup.
Our Redarc DCDC in-vehicle battery charger is the model BCDC1240D, 40 Amp version.
Redarc DCDC Charger BCDC1240D
The Redarc DCDC 40 Amp in-vehicle battery charger must be one of the best in-vehicle battery charges in the Australian market. Built in Australia and tested in Australian conditions, this battery charger will work in Australia’s harshest environments. The Redarc DCDC in-vehicle battery charger can handle temperatures up to 80 degrees Celsius and anything else you might throw at it. This Redarc model features a Maximum Power Point Tracking (MPPT) solar regulator allowing it to charge from both solar and our 4WD’s alternator simultaneously. It also has Green Power Priority meaning solar input is given priority over any other power input putting less load on our 4WD’s alternator.
We decided to use a Redarc DCDC in-vehicle battery charger for our second (dual) battery in our 4WD due to reliability. In all our 4WDs we have always used a Redarc in-vehicle battery charger and never had an issue. On top of that, Redarc units are built here in Australia and tested in our harsh Aussie conditions. They are tried and tested and do not usually fail. These chargers are super expensive, but this is the one bit of gear in our 4WD setup where we will not take a risk. Our second battery is one of the most important things in our setup and we need to ensure that there is minimal risk of something going wrong. If our second battery fails then we lose power to our fridge, compressor, communications, 240V inverter, trailer, and all our devices. This is one area where we refuse to go to cheap and in our opinion spending a few extra dollars ensures we are not going to have any issues with our 12V electrical setup in our 4WD.
Our Redarc DCDC in-vehicle battery charger was sourced from Speedy Towbars who assisted us in running all the wiring and installation of the charger.
Redarc DCDC Charger Features
The below is a high level summary of the main features of our Redarc BCDC1240D charger.
- Separate DC and solar charging inputs.
- In-built solar regulator.
- Maximises the performance and life of your second (dual) battery.
- Simultaneous DC and solar charging with Redarc’s Green Power Priority.
- Suitable for AGM, GEL, standard lead acid, calcium, and Lithium (LifePO4) batteries.
- Small and compact unit.
- Colour coded wiring for easy DIY installation.
- Recommended for battery sizes greater than 200AH.
Green Power Priority
Green Power Priority is Redarc’s term to describe how solar input is given priority over other charging sources for your second (dual) battery setup. Our Redarc DCDC in-vehicle battery charger has Green Power Priority which means that as soon as we have a solar panel connected, this solar input will be given the priority to charge our second (dual) battery over any other power inputs. Solar is given priority, then AC Mains power (if applicable), and then finally to DC Vehicle power. Green Power Priority ensures that there is less load placed on your 4WD’s alternator. With the BCDC1240D in-vehicle charger we will never has this connected to AC Mains power, so this is only relevant for Redarc’s battery management systems that come with 240V AC Mains charging capability.
In our setup we have run the wiring for the solar input to the rear of our 4WD. You can see the green anderson plug in the photo below. This is a great idea if you are even planning on using solar to charge your second (dual) battery. Having an external anderson plug means we don’t have to leave a window or door open when running a cable from our solar blanket to the Redarc DCDC charger.
Battery Size vs Charger Size
Our Redarc DCDC 40 Amp in-vehicle battery charger is recommended for battery sizes greater than 200 Amp Hours (AH). Redarc recommends their 25 Amp DCDC in-vehicle battery charger for batteries smaller than 200AH.
We chose the 40 Amp in-vehicle battery charger as initially we thought we would run two 125AH AGM batteries. However due to space limitations and the weight of AGM batteries at around 30 kgs each, we have now decided to upgrade to one 125AH lithium battery. Unfortunately, we now have a battery charger that is far bigger than we need and run the risk of degrading the life of our battery, but this is something we will have to deal with.
Charging Profiles
One great feature of the Redarc DCDC 40 Amp in-vehicle battery charger is its charging profiles. This charger is suitable for AGM, GEL, standard lead acid, calcium, and Lithium (LifePO4) batteries. On the front display of the charger, you can see four charging profiles listed as A through to C with Li for Lithium. When installing the DCDC in-vehicle charger, you will need to setup the correct charging profile for your battery type. By setting up the correct charging profile this ensures your battery receives the correct maximum charging voltage. Refer to your battery’s charging requirements to select the correct charge profile.
- Charge Profile A – 14.6 Volts Maximum Voltage and 13.3 Volts Float Voltage
- Charge Profile B – 15.0 Volts Maximum Voltage and 13.3 Volts Float Voltage
- Charge Profile C – 15.3 Volts Maximum Voltage and 13.3 Volts Float Voltage
- Charge Profile Lithium (Li) – 14.5 Volts Maximum Voltage and 13.6 Volts Float Voltage
When installing the Redarc DCDC in-vehicle battery charger, you select the different charging profiles through different wiring configurations. For example, to select the Lithium (Li) charging profile, you connect the orange and green wires on the DCDC charger. For profile A, you would leave the orange wire disconnected. For profile B, you connect the orange wire to your ground connection. For profile C, you connect the orange wire to the red wire. As we currently have an AGM battery as our second (dual) battery but knew at the time of installation that we would be upgrading to a lithium battery, we made sure that we kept the green and orange wires disconnected but easily accessible to connect these two wires when we made the upgrade. Currently we are charging our AGM battery on charge profile A which operates the DCDC charger at a maximum voltage of 14.6 Volts. Here we left the orange wire disconnected.
Be aware that the above listed charging profiles are for installation inside your 4WD. If you are installing your DCDC in-vehicle charger in the engine bay the charging profiles will change. This is clearly documented in the Redarc manual which we have included at the bottom of this post. Redarc do not recommend installing Lithium batteries in the engine bay.
How the Redarc DCDC Charger Works
The Redarc DCDC in-vehicle charger is a three-stage charger. This means the charging process goes through three stages being boost, absorption and float.
When our Redarc charger is turned on, either by our 4WD’s ignition or solar input, it goes into the boost charge stage. In the boost charge stage, the charger will maintain a constant current until the battery reaches its absorption stage. Here the voltage will increase to its maximum charging voltage depending on the charge profile set. The absorption stage is when the battery has reached a charge status of around 80%. In the absorption stage the charger will maintain a constant voltage and a declining current. This stage will take a lot longer to charge the remaining 20% of the battery but is required to charge the battery safely. The charge will continue in absorption stage until the current draw on the output battery drops below 4 Amps. Once this occurs, the charger will move into the float charge stage. In the float stage, the charger will maintain a voltage of 13.3 Volts for charging profiles A to C and 13.6 Volts for the Lithium profile. This continues to keep the battery topped up. As the battery starts to lose charge, the DCDC charger will move back into the boost charging stage and continue through the above cycle.
Installation
We have already covered off the four different charging profiles and how these are setup by the different wiring configurations. Here is an overview of how the Redarc DCDC in-vehicle battery charger should be installed correctly.
The Redarc DCDC in-vehicle battery charger has seven wires that are all colour coded for easier installation. When installing the DCDC charger you simply need to connect the below wires as follows:
- Brown – connected to the positive terminal on your second (dual) battery. This must have a fuse between the DCDC charger and second battery; 60 Amp for the 40 Amp charger and a 40 Amp for the 25 Amp charger.
- Black – connected to your earth on your 4WD’s chassis.
- Blue – connected to your 4WD’s ignition.
- Red – connected to your starter (main) 4WD battery. This must have a fuse between the starter battery and DCDC charger; 60 Amp for the 40 Amp charger and a 40 Amp for the 25 Amp charger.
- Yellow – connected to your solar panels usually through an anderson plug connection.
- Orange and Green – refer to charging profiles above to see how these need to be connected based on the battery type and maximum charging voltage.
The colour coded wiring makes installation straightforward but of course time consuming as it always is with wiring.
Location of DCDC Charger
You can mount the Redarc DCDC charger in many different locations including inside your 4WD, in the engine bay and even along the chassis rail. The optimum operating temperature is below 55 degrees Celsius and the unit does require decent airflow. The charger will still work above 55 degrees Celsius but not as well and will turn off at 80 degrees Celsius. You also need to make sure that wherever you mount the charger you are still able to see the front display panel in the event there is ever an issue.
Wherever you chose to mount the DCDC charger, make sure that it is as close the second (dual) battery as possible. If you are mounting the charger in your engine bay you need to ensure that it is kept as far away from high temperature areas as well as locations where it will not be covered in mud or other dirt. We have mounted our Redarc DCDC in-vehicle 40 Amp charger behind our fridge in the rear of our 76 Series Toyota Land Cruiser, right beside our second (dual) battery.
Cable Sizing
Redarc provide recommendations for the cable size that should be used in the installation based on the length of cable and the charger size. The longer the cable install length, the thicker the cable will need to be. You will also need to use a thicker cable for the 40 Amp charger over the 25 Amp. Refer to the Redarc manual that we have included below to see the table highlighting the different cable sizes based on the charger size and length of cable being used.
Fuses
As we have the Redarc DCDC 40 Amp in-vehicle battery charger we used a 60 Amp MIDI style fuse. For the smaller 25 Amp charger you only need to run a 40 Amp MIDI fuse. Redarc do not recommend using blade type fuses as these can result in a high resistance connection that causes high temperatures and damage to the wiring and fuse holder.
- 40 Amp DCDC Charger – 60 Amp fuse.
- 25 Amp DCDC Charger – 40 Amp fuse.
Technical Specifications
These are the specifications of our Redarc DCDC in-vehicle battery charger (BCDC1240D) based on Redarc’s documentation and website:
- Input (Operating) Voltage – 9 – 32 Volts DC
- Output System Voltage – 12 Volt DC
- Maximum Charging Voltage – 15.3 Volts
- Output Current Rating (Cont.) – 40 Amps
- Input Fuse Rating – 60 Amps
- Output Fuse Rating – 60 Amps
- Warranty – 2 Years
- Output Power – 600 Watts
- Width – 120 mm
- Height – 37 mm
- Length – 165 mm
- Weight – 1 kg (1,000 grams)
Redarc DCDC Charger Is worth It
As we highlighted at the start of this post, we are of the opinion that there is not much better than the Redarc DCDC in-vehicle charger. There are definitely other great products in the Australian market, we are not disputing that, but the Redarc DCDC chargers are definitely the best. They are tried and tested in Aussie conditions and will handle everything you can throw it. With the best you can expect to pay a hefty price tag and Redarc is no exception here. The 40 Amp model, BCDC1240D, that we have retails for $722. The 25 Amp model, BCDC1225D retails for $622.
There are definitely other areas of your 4WD 12V setup where you can save a few dollars. The DCDC charger and battery are probably the most important parts of any 12V setup. As a result we would recommend trying to get the best products here and get some of your money back by saving where you can on other things. This could be with your lights, inverter and solar. You don’t need a lithium battery, although they are fantastic, so if you have the GVM and space, get a big AGM or a couple smaller ones. We have used Adventure Kings AGM batteries for years and never had a problem. But I would not go cheap when it comes to your DCDC battery charger as you don’t want to be facing issues in the middle of the Simpson Desert.
One other thing when it comes to Redarc products is their support. If you have an issue you can just call them and someone will answer and can discuss your problem if you are having one. We have had to do this once and someone was able to point us in the right direction, which of course was something silly that we had done.
We hope you have enjoyed this post on our Redarc DCDC in-vehicle charger. If you would like to read more posts on our 4WD’s 12V electrical setup check out these other posts here. This is not a sponsored post but our opinion of our own Redarc gear. If you have any questions or comments then please comment below this post. If you would like to become apart of the 4WD Adventurer community to keep up to date on future posts and what we are up to then join here.
Thanks for reading legends.
The thoughts of Peter.
