I started drifting to LED's over 5 years ago when I still had the '99 Sunline. I ordered a few 921 replacements and immediately discovered that they were way too dim compared to the incandescents. So it was research time. I found that a 921 incandescent puts out about 264 lumens so any LED replacement has to be reasonably close in output. Here are the lumen outputs per chip for some of the common LED's:
- 5050 = 15 lumens
- 1210 = 7-8 lumens
- 3528 = 5 lumens
- 5730 = 50 lumens
So, by dividing the lumen output of the target lamp by the number of lumens per chip, I can figure out how many chips need to be on an array to be a satisfactory replacement. Here's the lumen ratings for common incandescents found in an RV:
- 921 = 264 lumens
- 1156/1141/1076 = ~400 lumens (1157 on bright side, too)
- G4 10W = 160 lumens
- G4 20W = 350 lumens
- G4 35W = 650 lumens
I did find that a slightly lower lumen output from an LED is generally 100% satisfactory, at least in the warm white fixtures. The bright white was an immediate NO GO! for the wife.
For the standard RV overhead light fixtures, both single and double, I opted for the flat rectangular arrays with an adhesive backing. They come with little adapters for 2 or 3 different base types, including the T10 wedge. Unlike the "bulb" shaped arrays, all the light is directed downward so these work really well in these fixtures. I found that, for us at least, any of these that are at least 200 lumens are just fine. YMMV.
There is one of these single fixtures over each side of the bed as a reading light. DW likes the full brightness, but I do not so my side was a perfect place to use up one of the "too dim" LED's that I bought early on.
I've had good luck bargain shopping on Ebay over the years. The Cougar needed over 60 bulbs to be replaced. I finished the conversion several years ago, and have maybe lost 2 LED arrays to failure since then. If they're going to crap out, they do it pretty quickly, otherwise, they're in it for the long haul. I am very comfortable with that.