The best way is to run the house off the batteries all of the time.
Have the external supply - can change as needed - charge and supply
load current when strong generation is available.

So when the wind stops or the furnace cools after midnight - you run
on batteries until you get power - or you run out of batteries.

The batteries can supply DC for some lights. inverters from batteries
cover all the rest.

Just like a large UPS - no switching in and out just always run.

Martin

wrote:
Hey folks, I've been having trouble getting an answer to my question
from off grid sites. I'm hoping someone can help me or point to the
right place. I am planning an off grid system. The house will be run
off of a bank of batteries with an inverter to supply AC power. My
question is on the charging of the batteries. In general, is it
better to supply the batteries with DC power generated consistently
over time or to supply AC through a charge controller for shorter
periods. I plan to use solar and wind but may have to rely on a
generator for some periods. The generator is the part that has me
stumped. Tho the generator will run off renewable fuels, I'm unsure
whether to run a large generator making AC for a short time, or run a
smaller generator making DC power for a long time. I had considered
an engine small enough to drive generators the size of those found in
wind generators. Any help or direction would be appreciated. Thanks,
Paul