What kind of light bulb (how many watts) was typical in a fall out shelter running on a 12 volt battery?

Answer 1

Not very many. The human eye can see a lot in a very dim place. 5-10 watts is more than sufficient

Answer 2

A 1000 watt inverter sounds about right. Forget having two seperate inverters and battery banks unless there's some really compelling reason to do so. If you want to charge the batteries with an engine generator build your own. An AC genny pushing a 100 amp battery charger is going to be very inefficient and not live very long, besides which a decent charger capable of putting out this number of amps on a day to day basis cost over $500 (just for the charger). More efficient, cheaper and better would be using a 11-12 horse engine spinning a 130-150 amp Prestolite or Leece Neville alternator from an ambulance of police vehicle to put 100 amps into the batts.

You really should be looking at reducing your loads. You're talking about using 7kWh (7000 watt-hours)in a 12 hour period. This isn't a sustainable level of consumption unless you're ready to spend about $20-$25,000 for a hybrid solar/wind system (generally good wind in TX). Wish I could sound more positive but I'd rather tell you the truth than have you sitting in the dark cursing us for not telling you what the reality of it was. Download the LOADCALC.PDF file from our website and also the article on building your own DC engine/alternator system. We also have an article this issue on converting a gas Generac genny to propane also including a special lo-tone muffler. Your can download an electronic edition of the mag for free (also sold on newstands).