So just like the dash heat will not properly heat the cabin going down the road, it also won’t cool the cabin when the outside temperature goes into the 70’s and the sun is hitting the coach. So we have to run the roof AC, and to power it the generator. But, we already have a big motor running, and although it will steal some HP (all “work” costs energy somehow) could we use it to produce the energy needed to run the roof AC and not have to run the generator for hours on end? Yes we can.

If the engine were to produce enough 12VDC to power a large enough inverter it could run the AC just fine. In fact it almost does produce enough power, but not quite. So what do we need? The AC runs about 12A at 120V. That’s 1440W. So a 2000W inverter as installed was inadequate. With a bigger inverter the startup load will be absorbed by the batteries. 1440W is 120ADC, on top of whatever the chassis needs to run. The alternator as installed is 150A. So we need a bigger alternator. And we’ll need to probably upsize some wiring. And last bot not least improve control and monitoring.

So again: here are the steps that need to be taken:

• Upgrade the inverter
• Upgrade the alternator, and if necessary the wiring
• Though not per se necessary upgrade the battery bank
• Upgrade the battery combining/isolation
• Upgrade the battery monitoring.

Inverter upgrade.

DONE! Read here.

Alternator Upgrade