In this article we have analysed two of the most poular DC to DC chargers on the market and assessed them against a range of important factors including solar capability, battery compatibility, ease of use, and safety.
This side by side comparison takes a look at the similarities and differences between the Projecta IDC25 and the Redarc BCDC1225D so you can find the best option for your next adventure.
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Projecta vs Redarc Comparison Table
DC to DC Charger | Projecta IDC25![]() Buy at eBay | Redarc BCDC1225D![]() Buy at Amazon |
Our Verdict | Best for Larger Batteries | Most Versatile |
Size | 149 x 122 x 42mm | 165 x 120 x 37mm |
Weight | 800g | 1kg |
Batteries Supported | Gel, AGM, Wet & Calcium | Gel, AGM, Standard Lead Acid, Calcium and Lithium (LiFePO4) |
Input Voltage | 9 – 32 Vdc | 9 – 32 Vdc |
Output Current Rating | 20 – 25A | 25A |
Battery Capacity | 75 – 300 Ah | 75 – 200 Ah |
Operating Temperature | -10°C to +80°C | -10°C to +80°C |
Warranty | 2 years | 2 years |
Other Features | Remote status indication, ignition connection | Trickle charge, waterproof |
Check Price | eBay | Catch, Amazon, eBay |
Key Similarities
Size and Weight
There is not much difference between the size and weight of both of these chargers. The Projecta is the lightest option at 800g and sits at 149 x 122 x 42mm. The Redarc BCDC1225D is 165 x 120 x 37mm and weighs 1kg. As you can see, they are both compact, sleek options which helps make installation easier. The slim size means you can install the charger wherever it is best suited, even in unusual locations if you need to (such as the car door panel).
Operating Voltage
The operating voltage of both DC charger units is 9-32Vdc. This means they are able to support a range of voltages.
The range remains 9-32V for the BCDC1225D regardless of input but the maximum solar input on the IDC25 is 28Vdc and 385W. Don’t worry, it can still be used with 12V and 24V solar panels which is a huge help for off-grid use.
Output Current
The Projecta offers a 20A output current when the input is 9-11Vdc and 25A when at 11-32Vdc. The Redarc offers a rating of 25 Amps and an output power of 375W.
Solar
One of the big benefits of both of these models is the dual mode. They are able to operate off a solar panel which is fantastic for off-grid or longer trips.
The BCDC1225D in-vehicle charger technology means it charges from the DC and solar input simultaneously. It also has Green Power Priority meaning it uses the renewable first which reduces the load on the battery system.
The Projecta IDC25 takes charge from the alternator and solar at the same time. It can function as a Maximum Power Point Tracking (MPPT) control to maximise the panels for the solar energy supply.
Durability
Both of these systems are extremely tough and reliable. They can both operate in ambient temperatures of -10°C to +80°C. It’s good to know both systems will be able to handle these extreme temperatures that can be found in engine bays during Australia’s hotter months.
The Redarc DCDC charger is also fully waterproof so can handle deep water crossings without issue. The Projecta has an IP rating of 67 meaning it is dust, splash and shock-proof.
Smart Alternator
Both chargers have dual charging modes and can work with standard or variable/ smart alternators.
Ease of Use
The IDC25 has indicator lights that let you know when the DC charger is charging, how it is sourcing its power and the type of battery being used. It also has an additional wire that can be installed in-cabin to display the charger status and it can be connected to the ignition so it only operates when the ignition is on.
The BCDC1225D also uses indicator LEDs to let you know the charge profile and status. This charger also has many user-friendly features including a built-in regulator that automatically delivers the correct charge. This means you can directly connect the unit to your panel without using a separate regulator. There are also separate DC and solar ports for ease of use.
3 Stage Charging
Both use a 3 stage process that is ideal for deep cycle batteries. The 3 stages on the Projecta are bulk charging, absorption and constant voltage float. This process ensures a safe and full charge.
Installation
Each DCDC system offers flexible installation options. They can be installed in the engine bay or inside the car, van or camper trailer. Installing with the wiring and mounting is straightforward, just make sure you follow the instructions to get everything connected up properly.
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Key Differences
Supported Batteries
The Projecta IDC25 is multi-chemistry and the profile can be set to charge different battery types at the push of a button. Battery types include Wet, Calcium, AGM and Gel but it is not suitable for Lithium batteries.
The BCDC1225D has been upgraded to include a new charging profile which means it can be used for Calcium, AGM, Gel, Standard Lead Acid and Lithium (LiFePO4) batteries.
Battery Capacity
The Redarc model is suitable for 12-24 volt vehicle systems and battery banks of 75-200Ah. If you have higher capacity needs then the Projecta may be better suited as this can be used for batteries of 75-300Ah. Both are able to be used for powering a fridge, lights and more.
Trickle Charging
The Redarc DCDC charger has a float mode when the secondary battery is full. This means the unit stores excess power and delivers a trickle charge of 0.5-amp. This can be immediately delivered when it is needed and it won’t drain your primary battery. This also gives the standard/ smart alternator a chance to keep up with increased usage. This feature helps to maximise the life of your aux battery system.
Safety Features
Both offer a range of safety features to ensure the system is working properly and safely. This extra support helps to prevent damage to the battery.
- Projecta – spark-free protection, over and under voltage protection, over temperature protection
- Redarc – dual battery isolation, voltage spike protection, overheating and reverse polarity connection protection.
Price
The Projecta DCDC charger costs less than the Redarc battery charger. Both offer excellent customer support and 2 year warranty periods.
Choosing Your Battery Charger
Projecta

Redarc

The best DC charger for you will depend on your needs. Both DCDC chargers discussed are reliable and, as you can see from our comparison, they share a lot of similarities.
The Projecta model is the best option if you are looking for an affordable charger that can be used with battery banks up to 300 Ah. The ability to use this as a MPPT controller is great if you will be using the system off-grid. The Projecta IDC25 doesn’t offer quite as many features and options as the Redarc but is still a strong option.
The Redarc charger is the best option if you want a user-friendly system that offers a lot of flexibility. The charger can be used with Lithium batteries (LiFePO4) as well as other battery types and it works incredibly well with solar. It is a reliable, waterproof option that offers variable voltage so it is only using what is actually needed.