Multiple batteries onboard a boat create independent systems that provide a level of functionality or security depending on your boat’s needs. It’s important to ensure those batteries are charged properly so that you can rely on them when you need them. Victron DC-DC chargers allow boat owners to efficiently charge one battery bank from another while protecting both batteries with intelligent charging algorithms. They improve charging efficiency, support multiple battery voltages, and are ideal for modern marine electrical systems.
Problems with Traditional Charging Systems
Typically, boats have a start battery and a house battery. How those are configured depends on the boat owner’s priorities. Often, the alternator is tied to the start battery to ensure these are full and able to power the engine. Sometimes they will have an isolation splitter that divides alternator output to multiple batteries. This setup ensures the start batteries are always supplied with a charge while the engine is running. The problem being that, if properly sized, the start batteries use very little power to start an engine. In that case, the alternator’s power production might be wasted on a full battery.
Most Boat’s have devices requiring power 24 hours a day, especially if the boat owner is away. For example, a bilge pump needs power to keep up with the mysteriously slow leak that can’t be found. Some will put that on the house bank, because it can withstand a deeper discharge, and for example the popular Rule 200 pump only draws 8ah at 12v. When the sun is out, solar panels that will provide enough power to keep the house bank topped up. Shore power certainly would keep the batteries charged, but shore supply is not always as consistent as we would like.
This configuration of battery and charge source ensure that the batteries are being charged and, if properly sized, meeting your power demands. However, its complex doesn’t take full advantage of your power sources (alternator, solar, shore). Pairing one battery to one power source wastes valuable energy once that battery is full. Charge splitters may charge both batteries, but they are inefficient. If the loads on one battery are greater than the charge source, then the battery can be significantly depleted. It’s even more complicated on boats with multiple voltages. How do you get a 12v alternator to charge your 12v battery and your 24v house bank?
Why Use a DC-DC Charger?
The best answer to all of these are DC-DC chargers. A good DC-DC charger will charge one battery from another while monitoring and compensating the state of charge for both batteries. This way, you can consolidate power sources to one battery (probably the house bank) and then charge the start once the house is full, or nearly full. If the house bank is depleted, the DC-DC charger will cut off charge to conserve power to the supply and you still have a full start battery to run the engines and engage the altern ator.
Victron Energy’s line of Orion DC-DC chargers work with 12v, 24v, or 48v systems. The Orion range of products is too long to list in one blog, which is good because it means they will have one that fits your boat!
Victron Orion DC-DC Charger Features
The modern Victron Energy DC-DC chargers share much of the same functionality. The Orion XS and Orion-TR Smart chargers have bluetooth that allows you to monitor and program them via VictronConnect. They can also be integrated into a Victron ecosystem by pairing them to a GX device like the Cerbo or Ekrano GX. The GX devices also allow remote monitoring and control via the Victron Remote Management Portal (VRM). The Orion series DC-DC chargers have preset multi-stage charge cycles for their programmed voltages. However, if you need something specific, you can build custom charge profiles. If no cycling is needed, you can place them into power supply mode. Power supply mode outputs consistent voltage and adjusts current as needed. If required, you can disable the preprogrammed charge algorithms and allow the Victron GX device to use Direct Voltage Current Control (DVCC) to synchronize Orion DC-DC chargers and other Victron products.
The Orion DC-DC chargers have a variety of safety and efficiency mechanisms. The devices have a low battery cutoff which shuts down and prevents charging when the supply battery voltage reaches a programmable low threshold. It will monitor the supply battery voltage until it reaches a programmable allowed-to-charge voltage. On the receiving side, if battery temperature monitors are enabled(or the data is supplied by a BMS), the Orion chargers will increase or decrease the charge voltage to compensate for hot or cold receiving batteries. This will prevent charging or discharging outside the limits of the battery.
Orion XS
The Orion XS series predominantly caters to 12v/12v systems that require higher charge current at 50 or 70 amps. These are great for if you have a battery such as lithium, gel, or TPPL that can accept or discharge more amperage. The Orion XS 1400 is unique in that it has a 12v input and can be programmed to output 12v or 24v depending on your needs. These chargers are 98% efficient at converting power (some energy lost to heat). When not in use they draw only 1.5mA (.015a). Keep in mind, these chargers are non-isolated, meaning that both supply and accepting battery banks share a common ground. If they fit your system, these chargers will distribute power as efficiently as possible.
Orion-TR Smart
The Orion-TR Smart series DC-DC chargers fit a wide variety of systems. These chargers have a combination of battery voltages and current output to fit any system. The lowest wattage device is the 220w 12-12/18a charger, the largest being a 24-48/8.5a charger. Devices in the middle include 24-12/20a, 12-48/8a, 48-12/30a, and many more. Checkout the Orion-TR Isolated Smart DC-DC Datasheet to see the full range. These models come isolated or non-isolated to best fit your system. Though these chargers are 87-89% efficient, they are the most versatile range of DC-DC chargers. Many boat owners build high efficiency energy systems using 48v house banks, but still need a 12v source of power for some electronics. The Orion-TR series is the best fit as a stand alone power source, or to keep a separate 12v battery charged. Whatever your system needs, the Orion-TR is ready to go.
Which Victron DC-DC Charger Is Right for Your Boat?
DC-DC chargers are the best way to charge multiple batteries onboard one boat. Consolidating charge sources to one battery allows faster charging especially its been depleted by 24hr loads or even heavier use. When programmed appropriately, your Orion DC-DC charger will top up a secondary battery on an as needed basis. The potential configurations and uses of these chargers is as expansive as Victron’s Orion DC-DC Charger product line.
Whether you’re upgrading to lithium batteries, installing solar, or redesigning your boat’s electrical system, a Victron Orion DC-DC charger can improve charging efficiency, extend battery life, and simplify multi-bank charging. Choosing the right model depends on your battery chemistry, voltage, and charging requirements. If you’re unsure which Orion charger best fits your boat, OceanPlanet Energy can help design a reliable system tailored to your needs.
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