DC-DC Alternator Charging

DC-DC Charging: Using Drive Time to Charge Your RV

Plan alternator charging around the vehicle, driving time, battery limits and charger controls.

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Ah (amp-hour)

A measure of electric charge: one amp flowing for one hour is one amp-hour. Compare battery energy at the same voltage, or convert nominal capacity to watt-hours with…

Alternator

An engine-driven source of electrical power that supports the vehicle’s electrical system and charges its starting battery. House-battery charging must account for the capacity left after vehicle loads.

AWG

American Wire Gauge, a conductor-size system in which a larger numbered gauge generally means a smaller conductor. Cable selection also depends on insulation, installation conditions, length, and current.

BMS

Battery management system. It monitors battery conditions and may restrict charging or discharging when limits are reached; it does not replace correctly selected external wiring protection.

Breaker

A resettable device that opens a circuit under specified fault conditions. A breaker must be rated for the AC or DC circuit in which it is used.

Busbar

A conductive bar used as a common connection point for several circuits. Its rating and protective cover are part of the system design.

Crimp

A connection made by compressing a terminal around a conductor with a suitable tool. The terminal, cable size, die, and tool must be compatible.

DC-DC charger

A charger that takes DC power from one source, often a vehicle electrical system, and controls charging of another battery. Output current, input limits, and battery settings are…

Derating

Reducing equipment output or allowable loading under conditions such as high temperature. A nameplate rating may not be available continuously in a hot RV compartment.

Disconnect switch

A switch intended to isolate part of an electrical system. Whether it may interrupt a live load depends on its rating and the installation design.

Fuse

A replaceable protective device that opens a circuit when its specified overcurrent conditions are reached. Selection includes current, voltage, time-current behavior, and interrupt rating.

Isolator

A device or arrangement that separates battery banks to limit unwanted current flow between them. Isolation alone does not provide the charging control of a DC-DC charger.