I'm working on the wiring harness for a PC build that's going to include a bunch of (5050) LED strip lights.
The strips will be wired to fan connectors (more details at end). For testing, I've been running them off of a SATA to fan splitter (e.g. this) connected to a stock SATA power cable. However, I'm going to have a lot of wires to cram under the PSU shroud and the splitter and stock SATA power cable are adding a bunch of bulk (and TBH, the splitter feels a little sketchy). Since I don't need 5V anywhere, I'd like to build some cables that don't have unused wires.
My initial thought was to build a peripheral cable that would run PSU → SATA (for some case fans) and somehow chain fan connectors off the end of that. (Or maybe with the SATA at the end.) However, to do this I would have to double-crimp a bunch of fan pins, or build a 2x SATA cable and keep the splitter. And in either case, I would also need fan extension cables, and 100% of the total load is being carried by a single pair of wires.
Then it occurred to me... I'm almost certainly never going to be using more than 4 out of 6 of my EPS/PCI ports otherwise... and an 8-pin EPS connector is 4x 12V pairs (compared to a peripheral connector which has only 1x 12V pair). AFAICT, although the pin pairing is a little screwy, there are no paired wires in the EPS cables, and the PSU end is also 4x 12V pairs. Physically, I could wire up a custom cable that plugs into an EPS/PCI port and has 4 separate 22/2 stranded 12V pairs coming off of it. This would add a little bit of extra wire right by the PSU, but each pair can be made to length (no extensions!) with a fan connector on the end (no SATA → fan adapters!), and each pair is only carrying the load of one set of LEDs.
Practically... Is this a good idea, or a terrible, terrible idea that will turn my Corsair AX1000 into an expensive paperweight?
All that said, I have already run the entire 5 meter strip off the stock SATA power cable → fan splitter → 4" 22AWG adapter, so the PSU does seem able to take the load on a single 12V pair (nothing caught fire, not did I notice any melting... aside from the LEDs themselves which put out much more heat than I would have expected). However this was only for maybe 30 minutes, where the completed harness is probably going to run 24/7.
In any case, the strips themselves are going to be connected with 22AWG solderless connectors (e.g. these) that have had fan pins crimped to the other end. Strips will be connected with either similar connectors (where possible; the pre-made connectors are only about 10cm long) or soldered with 22/2 between strips. The longest connected run will be about 1 M - 1½ M. Total lighting will be less than the 5 M reel (but possibly a significant portion thereof). Allegedly (read: according to the product description), the entire reel draws 38W, but what I have left of the reel (about 80-90%) only pulls about 2.3A (measured), so probably closer to 30W. Thus, each of the four runs, individually, will not exceed 1.5A, and probably closer to 0.6A each.
p.s. This is sort of very, very loosely related to Is it electrically safe to use an ATX PSU's PCI output for SATA/MOLEX instead of graphics cards?. Unlike that question, however, I'm powering LEDs, not HDDs, and only need 12V.