GotQuestions? Sleeper Cab Power Experts

Q. I already have an APU. What do I need an inverter for?

December 12, 2016

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A. An APU’s primary function is to take care of a truck’s heating and cooling systems. It has its own motor that charges the truck batteries and provides power for AC electronics. An inverter runs off batteries so it is ideal for relatively lighter loads such laptop, TV, blender, cell phone charger etc. An inverter with a built-in transfer relay, example Xantrex inverters offered by major truck manufacturers, will also pass through AC power to downstream loads when the truck is plugged into shore power. It is not cost effective to run an APU to power lighter loads.

The advantage of an inverter with a built-in battery charger is that it will charge batteries when the truck is plugged into shore power, for example at a truck stop.

Note some APUs have a built-in inverter that power AC loads with-in its power range. The APU comes on to charge batteries discharged by the inverter feeding other AC loads.

Author Bio

Steve Carlson

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Xantrex OEM and Fleet Manager

Steve Carlson is the Xantrex OEM and fleet manager. Steve has over 20 years of experience working in the industry. His positive energy, hands-on-approach and strong technical insight has proven extremely helpful to truck manufacturers, fleets and dealers. Steve has contributed to several editorials on sleeper cab power in leading truck and fleet magazines. In his free time which is very hard to come by, he enjoys fishing.


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