Glossary

Charging converter

Also DC-DC converter

What is Charging converter?

A DC-DC converter that charges between two battery circuits while regulating voltage and current. Both sides remain electrically isolated or at least decoupled.

What matters about Charging converter in practice?

It is the clean way to operate a lithium battery bank behind a lead-acid battery: the alternator charges the lead-acid battery, the converter charges the lithium battery bank. If the battery management system disconnects, the alternator does not notice.

The same type of component also links 24- and 12-volt levels in a mixed system. Sizing depends on the continuous and inrush currents of the connected devices.

Isolated or non-isolated DC-DC converter?

In an isolated converter, input and output share no common negative. That is necessary when two on-board systems must stay separate, for example a 24 V vehicle system and a 12 V living-area system with its own negative potential. Non-isolated converters are cheaper and suffice when both sides use the same negative.

What are DC-DC chargers used for?

  • Charging a lithium battery behind a lead battery with its own charging profile.
  • Supplying or charging a 12 V circuit from a 24 V system and vice versa.
  • Compensating long cables when a defined voltage is needed at the destination.

What to watch when sizing

Continuous output current, input current including efficiency, fusing on both sides and a switch-on condition so the converter does not drain the source. How a DC-DC booster is used as a special case is described under DC-DC charger.

Related terms

All terms from A to Z

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