Hi All,
I just bought a PowerOak K2 battery bank to use with my Bluesound Vault streamer. This is a 50,000 mAH battery bank that has 20V/3A, 12V/2.5A and 4 x 5V/2.1A outputs. It also allows you to discharge while charging, so you could leave the charger hooked up and still get battery power, although it is probably cleaner disconnected.
I am not sure how many hours I will get out of it yet but my initial tests indicate significantly better sound than with the standard DC power supply (switcher). Given that the max consumption of my Streamer is 17 watts (I think this is the consumption when actually ripping cds) This thing should be able to run at least 15 hours on a charge if not more. The BlueSound node only consumes 3 watts (I think the Vault would be similar when only streaming) and when you consider what a laptop consumes then this battery should last a long time between charges.
The battery is Li ion and comes in a very nicely made aluminum chassis and it is quite compact and not too heavy at 1.3Kg.
I will report back more as the listening unfolds and also right now while my better DAC is being repaired I am using the built in DAC, which I thought was kind of crap but now it sounds at least acceptable...until I get my old one back. I am wondering then if it will consume even less power when I take the digital output instead of the analog outs.
To my knowledge, this is the most powerful of this easily portable class of battery bank. Of course, you can buy some large, off grid supplies and even power your whole system...if you really want clean power all the way around.