Originally Posted by Rivetedude
I have a work light at home that takes the 12v
bulbs. It's the kind where the bulb is in a little cage and you hang it under the hood and hook it up to the battery. I was able to find the bulbs for it at Wal-Mart I believe. Either there or Ace. I forget exactly, but I know they were in the first (and last) place I looked and it wasn't an RV store.
I got a box of 6 at Napa, 75 watt, 12v
dc bulbs, for $4/each. You can get an adapter to screw into the 12v
sockets, so you can use the smaller 1141 car marker light type bulbs, to cut down on power consumption. If you read the packaging carefully, though, you will see they are around 40 watts or so themselves, and give off much less light. It is a consideration for boondocking, however, when every watt counts. Another more energy efficient option is to put in 1141-type LED's in place of the 1141 bulbs in the adapter. They aren't cheap, either, but last forever, and give off much more light, with even less power consumption, a quick forum search on LED interior lights should show you what you need to know about them.
By the way, here is a photo of our 63 with the 75 watt 12v bulbs installed and operating. Between them and the 110v bulbs, I can really light up the night now!