supplementing the battery

[rustygun]

The argument for smaller portable generators.

The whole idea of using reserve power is to supplement the existing motor home battery life, as well as being economical in the running costs. ( and not disturbing your neighbors)

As an example I would assume a 1000 watt roof mounted Air conditioner drawing 3amps would consume a 110amp wet cell battery in a matter of minutes. So if using 1000 watt generator ( giving 900 effective watts) , then it should hold the existing battery for at least 6 to 8 hours without going below the critical amp reserve. ( please correct my math here if I'm off on this calculation)

No doubt a larger 2000 or 3000 watt generator would run the entire motor homes power needs, but at what costs? double fuel consumption as well as a much higher noise level, not to mention the increased weight and cost of a larger unit.

There are obvious pros and cons to both size and capacity, but in and age of higher fuel costs and being "environmentally" minded ( neighbors) it seems to me that a smaller generator makes sense.

Any thoughts?

[Kjell]

Well, smaller is better in this case, which means smaller fuel Bill’s!
And with the new inverter equipped gensets the engine RPM will adjust itself depending on the load – less load means lower RPM - but you always get the wanted 50 Hz 230VAC . And lower RPM means of course less fuel consumption.

Today a MH owner who wants to run an AC but is off the grid, that MH owner just have to rely on a genset, there is no alternative as I see it.

But why run a oversized genset, buy a genset with a capacity closest above the AC power requirement but observe the current surge from the AC kompressor, you may need to step up somewhat on the genset power.
Be shure it is an inverter set if you would like to draw less power from it i.e. when charging batteries or using power for smaller appliances.