Hi,
I am about to put a pre-order on Pimax device 
Been wondering about Vive base stations. Some people claim on reddit they can be powered off USB, is that true? I found some units without PSU on eBay.
Also, do I gain anything of getting 2 bases instead of one for Sim racing/seated?
Cheers!
Vive LightHouse appears to use a 12v Adapter. So looks like a no go.
and discussion
Thanks, this thread mislead me: https://www.reddit.com/r/Vive/comments/52l5l7/base_station_usb_ports/
I probably could buy some cheap 1.5A universal PSU, just need to know the polarity.
Your welcome. Can’t day for sure you can’t but based on 12v vs 5v not likely.
If you can get a good pic of the psu sticker it usually will tell polarity.
Any thoughts on single vs double bases for seated/racing use?
I think I have a pile of 12v adapters piled up over the years from some older electronics, maybe one those will fit
For Seated experiences ine should be sufficient. Pimax has made it si a single LH can even be used for standing.
The polarity is center positive. I know this because I measured it with a voltmeter when I had issues with one of the OEM Power supplies. Most PSU’s will be center positive. OEM PSU is 2.5A so be sure to get at least that. The base stations have motor in them that probably requires some current(amps). Good luck
Thanks very much guys, you’ve been very helpful. Electronics isn’t my strong suit, so I might as well just buy PSU that’s listed as matched. Sorry i wasn’t backer of this effort early on, I am too much of a pessimist. But now, looks like we all are about to get devices of our dreams - exiting times.
Kickstarter are gambles no matter how for sure they seem to be. No reason not to be cautious & play it safe. Backing a project there is always a chance to receive nothing. 
Your very welcome.
I bought an extra basestation on eBay for seated gaming.
Didn’t come with a power adapter so I bought a universal adapter and it works fine.
Just make sure to get 2.5A+.
I bought this - You can probably find it on eBay too (GooBay is the make).
Thanks, did addition of a second base make a difference in seated experience? Also, do Vive bases have to be placed symmetrically or in any way you like?
Just placed my pre-order for 5k+! Yay!
I’m only using a single basestation when seated. More or less on top of where my monitor is.
When playing room scale stuff in another room where I have two basestations in opposite corners of the room (place around 2m up angled slightly down).
So do you turn the other base station off? Is there any harm in having two on while seated?
Yes, they’re connected to wall sockets work on/of switches so it’s no hassle to me.
You don’t have to turn them off as long as the headset only sees the ones it’s supposed to use.
No, there’s no harm in that.
Thank you. My setup is such that I do not want to drill holes, also, I do not want to have stands for bases. However, there will be a bit of obstruction between bases and HMD. So I am hoping that two bases will give more light for headset to capture and calculate position.
Is it acceptable to have base fairly close to headset, like 0.5m-1.0m?
It’s OK to have it close but if the view is obstructed tracking will fail/glitch (not very pleasant).
BTW, this is interesting: https://www.reddit.com/r/Vive/comments/51ir1h/vive_power_draw_test_results/
So base station draws up to 5W. Which means it needs 0.5A to run, and 1 or 1.5 should be plenty. I am just trying to avoid buying 2.5A PSU 
out of sport interest. (I have plenty of 12v PSUs from various electronics)
the original Vive Base station ac power adapter is 12V 2.5A 30W, vive link box ac power adapter is 12V 1.5A 18W, please do not make mistake.