You’ll require a dual battery setup to power your equipment while parked. Here, the separate auxiliary battery powers all of your appliances, including your refrigerator, lights, phone chargers, audio systems, etc.
The vehicle’s main battery will therefore continue to function normally and be ready to start the car when it’s time to leave, regardless of how much power these devices consume.
Unfortunately, your vehicle’s alternator will have trouble adequately charging and/or maintaining either battery due to differences in charging characteristics between various battery types and batteries at different levels of charge. This problem is resolved by a DC-to-DC charger. They are essentially smart charger that uses 12 volts, to put it simply.
You have come to the right place if you are attempting to determine the type of battery charger you will require. DC-to-DC battery chargers will be discussed in this article along with their functions, benefits, and methods of use.
A DC-to-DC Charger: What Is It?
A DC-to-DC charger is essentially a smart charger for your 12V system. It separates the house battery system from the alternator so that the car’s computer management system perceives it as a set of lights.
Simultaneously, it increases the charge at the house battery from as low as 9V back up to 14.4V (or higher, if necessary) to maximize charging capacity. It does this by delivering the charge in stepped form, similar to your smart mains charger so that it achieves a charge of almost 100% after a day of driving.
The majority of DC-to-DC chargers also serve as solar regulators, moving what was previously a separate component on your solar panel to a more advantageous location next to the house battery.
And these maximum power point trackers (MPPT) optimize the performance of your solar panels rather than being simple regulators.
The majority of DC-to-DC chargers require more amperage from the alternator than would be available if you allowed the alternator to “push” the cable down. This can quickly recharge the system for the house batteries and can be as high as 40A or more per hour.
New on the market, complete battery management systems (BMS) combine a mains charger, a DC-to-DC charger, and an MPPT solar regulator.
While expensive, these typically include a high-tech battery monitoring panel and require no post-manufacturer wiring to connect multiple units together. Cables measuring 6B&S/13.5mm² (the conductor, not the conductor plus insulation, as the most cable is sold) are advantageous for DC-to-DC chargers.
They function with smaller cables, but as the voltage drop through that cable rises, the heat produced reduces the conductivity of the cable, making the charger work harder, requiring more current, and producing more heat.
This may continue until the demand outpaces the alternator’s ability to supply. Heat is a wasteful way for energy to disappear.
Most of that voltage drop can be avoided by installing the charger close to the house battery, and maintaining the minimum clearance specified by the manufacturer helps to dissipate heat.
DC-to-DC chargers, in my opinion, ought to be installed as standard equipment or at the very least made available as an option on every camper and caravan offered for sale in Australia.
They increase the likelihood that your batteries will arrive in a camp close to being fully charged and reduce damage to your house battery system from over-discharging.
Direct Current (DC) Explained
Let’s expand on our discussion of DC (direct current). Direct current, or DC as it is more commonly known, is characterized by a constant voltage flow. Contrarily, the voltage flow of alternating current (AC) changes.
While the majority of the appliances in our homes still run on AC, DC is more effective and more common in small cars, boats, and vans. Chargers for DC and DC-to-DC batteries have become crucial components as solar power in vans has become increasingly popular.
Here is a comparison.
- A DC-to-DC charger also referred to as a battery to the battery charger, converts the output from your primary battery and charges your secondary battery efficiently.
- In most cases, the converted power is stored using a single battery or a system of batteries.
- The secondary batteries can be used to run large appliances like your refrigerator and for minor tasks like charging cellphones when powered by a DC-to-DC charger.
Pro-tip: You can efficiently charge your secondary battery using the DC-to-DC converter if you live a mobile van lifestyle and travel extensively.
The Function Of DC-to-DC Chargers
With a DC-to-DC charger, you can charge your off-grid battery with the same generator that powers your car’s operating battery. The alternator in your car produces DC energy that is used to power the electrical system and charge the starter battery while you are driving.
You can control the current with a DC-to-DC charger so that you can recharge your car’s battery as well as an off-grid battery. However, it will also control the current to increase the longevity of the automotive parts already in place.
You may not need to use solar panels at all if DC-to-DC charging is this effective. However, the dependability of DC-to-DC charging will depend on how much electricity you use in your car to run the A/C, car stereo, lights, etc. Less excess DC energy will be available to charge your battery the more energy you use to operate the vehicle and its appliances.
Getting close to nature and taking in some quiet time are big draws of camping, RV travel, and off-grid living. Therefore, hearing your gas generator hum is the last thing you want to hear.
Benefits Of Using A DC-to-DC Charger
Let’s look at some advantages of installing a DC-to-DC charger now that you have a solid understanding of what they are.
Overcome Issues With Smart Alternators
Nowadays, the majority of vans come equipped with intelligent alternators that reduce power output. As a result of their load restriction, they are unable to charge a backup battery. This issue is resolved by a DC-to-DC converter, which isolates the primary battery from the alternator.
Maximizes Main Battery Charge
The ability to maximize the charge of the primary battery is another advantage of installing a DC-to-DC battery charger. In order to quickly and effectively charge the primary battery, the charger can convert an amperage of as little as 9 volts up to 13.5 volts. After a good day of driving, your main battery should be nearly fully charged.
Works Without Solar Power
If you frequently travel in places where there is little or no sunlight, DC-to-DC chargers are also a blessing in disguise. Without having to worry about solar power or other energy backup options, DC-to-DC chargers can assist in charging the auxiliary battery that powers your devices.
Adapts To Different Batteries
The ability of a DC-to-DC battery charger to adapt to various battery types is one of its most significant advantages. This can save you time and money by preventing you from needing to purchase a new charger each time your battery needs to be changed.
A DC-to-DC charger also modifies the power according to the battery’s intended use, preventing overcharging from harming the battery.
Which Size DC-to-DC Charger Do You Need?
Typically, batteries up to 200Ah need a DC-to-DC battery charger of about 25Ah. A 40-ampere DC-to-DC battery charger will perform better for ampere-hours over 200.
If your alternator has a 200 amp rating, you should divide that amount in half to get the charged power. It is advised to run it at 50% because running your alternator at maximum output load is very taxing on the device and will eventually cause it to break down.
To select the best size for your DC-to-DC charger, you should consider the following:
- Alternator Size: Alternators typically have an output power range of 60 to 150 Ah, whereas DC-to-DC chargers have a range of 6 to 40 Ah. If you have a powerful alternator with more capacity, you should purchase a larger charger for the best performance.
- Battery Type: For conventional batteries like AGM and lead-acid batteries, a DC-to-DC charger rated at 20% of your battery’s amperage should be sufficient. You can increase your amperage with a lithium battery to almost 30% of its rated capacity.
- Voltage: It is advised that you match your charger to the electrical configuration of your van. For instance, a 12-volt DC-to-DC charger should be used if your system operates at that voltage (which is the most common).
- Usage: The size of your DC-to-DC charger is also influenced by your energy consumption. A DC-to-DC charger is required if you use multiple appliances with your auxiliary battery.
Is A DC-to-DC Charger Compatible With Lithium Batteries?
With lithium batteries, a DC-to-DC charger is unquestionably acceptable as it can prolong battery life. Your lithium battery’s life can also be increased with a DC-to-DC charger.
Here are some comparisons.
- Lithium batteries consume the maximum amount of power that is available, which can quickly cause problems if you are charging them directly from an alternator. This is due to the lithium battery adding to the alternator’s load if it already has a sizable load, which could lead to alternator burnout.
- To prevent overcharging a lithium battery and causing it to overheat, a DC-to-DC charger efficiently controls the power input.
- Additionally, the restart process and battery chemistry of these batteries are unique, making it challenging to charge them using an alternator or other non-conventional methods.
Final Words
The DC-to-DC Battery Charger is the brain that tells your alternator how to properly charge your house batteries. The life of your auxiliary battery can be extended and charging efficiency increased with a DC-to-DC charger.
You can completely secure your ideal off-grid lifestyle by having a variety of power generation sources. When residing off-grid, we advise having access to both a portable solar generator or solar panel solution and a DC-to-DC charger.
