DC-DC Converters

What is a DC-DC Converter?

A DC-DC converter converts direct voltage to direct voltage. Now you may be thinking why would I want that? The most common application of a DC-DC converter in off-grid systems is to connect two separate batteries. With a disconnect relay or diode bridge you actually connect the two batteries together with a fuse in between so that one battery does not drain the other. The condition for this is that one battery must have a higher voltage to charge the other. With a DC-DC converter you can turn a lower voltage into a higher voltage. This way you can charge another battery at 14.4 volts with a battery voltage of 12 volts. If you have a vehicle that meets the Euro 5 or Euro 6 standard, the vehicle lowers the battery voltage while driving to save fuel. When you brake the engine, the alternator switches on and charges the battery. This is only possible if the battery is not already full, which is why the vehicle drops the battery voltage while driving. The result is that the battery voltage is not high enough to charge the household battery. If you want to charge the battery while driving, you need a DC-DC converter.