What is a DC-DC Dual Battery Charger and do you need one?
— August 28, 2023 | 2 min read
PROJECTA INTELLI-CHARGE DC/SOLAR DUAL BATTERY CHARGERS
Whether caravanning, camping, 4WDing, or touring, there’s no better way to enjoying Australia’s great outdoors. To power your gear when parked up, you’ll need a dual battery set-up. Here, your fridge, lights, phone chargers, audio systems, etc all run off the sperate, auxiliary battery. So, no matter how much power these devices use, the vehicle’s main battery will remain unaffected, and ready to start the car when it’s time to head off.
Unfortunately, due to differing charging characteristics between different styles of batteries (such as a deep-cycle battery), as well as batteries at different levels of charge, your vehicle’s alternator will struggle to properly charge and/or maintain either battery. A DC-DC changer solves this issue.
On its own, that’s reason enough to invest in one. However, Projecta DC/Solar Dual Battery Chargers incorporate a host of additional features, as well as solving a host of other issues. Such as the inability of modern, variable-voltage charging systems to effectively charge an auxiliary battery. Or the voltage drop experienced by auxiliary batteries mounted a long way from the vehicle’s alternator. No wonder they’re one of Projecta’s most popular products!
What is a DC-DC charger?
In simplistic terms, they’re a smart charger that runs off 12-volts. They do this by taking the power output of your vehicle’s alternator and creating an output voltage and current that’s ideally suited to charging and/or maintaining your auxiliary battery. Alternators are not good at this, as they’re not dedicated chargers perse.
Their primary role is to power the vehicle’s electrical system – recharging the main battery after start-up is its secondary role. Alternators don’t perform well when trying to simultaneously charge a nearly full battery (main) and a depleted battery (auxiliary). By solving these charging issues, a DC-DC charger will increase the life and efficiency of your auxiliary battery.
Projecta IDC25 DC/Solar Dual-Battery Charger
This is Projecta’s biggest selling DC-DC charger. It’s compact, robust, versatile, easy to hook up and straightforward to operate. Let’s take a closer look at this feature-packed unit.
Advanced Three Stage Charging for longer battery life
- Stage 1: Bulk – maximum charge to quickly bring up a flat/depleted auxiliary battery.
- Stage 2: Absorption – For final top up. By dialing back to a lower, continual charge, it prevents overcharging – which is bad for any battery.
- Stage 3: Float – A small trickle charge to maintain the battery in a fully-charged, ready-to-go state.
- The IDC25 can tailor its charging characteristics to thoroughly charge the different types of commonly used batteries – including Gel, AGM, Wet, or Calcium – in both hot and cold conditions. *Note: Projecta offers the dedicated IDC25L to suit Lithium-Ion batteries.
- It will maintain correct output voltage with input voltages as low as 9 volts. This is vital when your auxiliary battery is mounted a long way from the main battery, such as in a trailer or caravan. As these long cable runs invariably suffer from voltage drop.
- Having a 12-volt set-up in your camper or trailer, but owning a 24-volt vehicle, is not a problem for the IDC25. With its intelligent internal voltage regulation, this unit can be connected to both 12-volt and 24-volt vehicles (36 volts max input) – while maintaining correct output for a 12-volt, auxiliary battery.
- No need to purchase a stand-alone MPPT solar controller (i.e., voltage regulator). The IDC25 features a dedicated input, which regulates your solar panel’s output voltage to power your accessories and/or recharge your battery when needed.
- The IDC25 will even allow you to charge from your solar panel while on the move, prioritising its output over your vehicle’s alternator to reduce fuel consumption. This happens automatically – no need to manually switch it over.
- With its IP67 rating, the Projecta IDC25 can handle extremes of temperature and is dust proof, splash proof, shock proof, plus vibration proof. This allows the unit to be mounted in almost any location – including in the engine bay.
- Detects reversed polarity connections, plus automatically shuts down if an over, or under voltage condition is detected – to prevent harm to your battery and electrical system. To stop sparking the unit does not start charging until the load is securely detected. And in addition to the status lights on the front of the unit, the IDC25 comes with provisions to remote mount an LED so that you can monitor charging and fault statuses from inside the cabin.
Solar Panel Voltage Regulator
On the go charging from Solar Panel
Flexible Mounting Options
You can now see why the IDC25 is so popular and why a DC-DC charger is one of the best investments you can make. Rated at 25 amps, the IDC25 is tailored for a typical, single auxiliary battery set-up. If you’re running bigger set ups, and/or multiple auxiliary batteries, the 45-amp IDC45 is the hot ticket.
One of Projecta’s Technical Support Officer, Ben Blood (better known as Benny) has put together a couple of great videos covering DC-DC chargers and the IDC25.
Benny (along with a team of qualified support technicians) also run the Facebook page, ‘Projecta Switched On’ Tech Talk – which covers 4x4, camping, auto electrical, and caravanning electrical questions. You can also call Projecta Technical Support (1800 422 422) and talk to them directly. Check out our website for more info and a full rundown on our wide range of products.