Battery Powered amps and preamps

Something struck me recently, as I discovered this group of equipment that was supposed to be battery powered. The Final line is no longer represented in the Western Hemisphere, perhaps it was too costly for what it offered, and there were not enough takers. When I read the review, it seemed that their battery powered unit blew the Gaincard out of the water and also went head to head with the Conrad Johnson Art preamp. Does anyone have any opinions about this type of gear? I have seen people advertising a N.E.W. amp that was supposed to be battery powered. I have no idea what they sound like or anything else. Any experience would be appreciated with this latest mystery. Maybe this might be the next step for many people who are fed up of upgrading to massively and inefficient gear.

Jeff Rowland uses battery technology on several products in his line. You can visit his web site, and view the Model 8 amplifier and Coherence preamp. In addition to technical specifications and images, there are reviews from Ultimate Audio by Greg Petan and Myles B. Astor.
The N.E.W. products offered good sound for the money. I have not had personal experience regarding reliability, but thought the amps and preamp sounded pretty good. I think the designer, (his name escapes me at the moment), is now working with Dennis Had at Cary.
I have been enlightened recently as to the potential use of a high-quality power inverter with a sufficient quantity of lead-acid batteries to effectively "battery power" one's system. I'm considering going forward with this to the extent of powering my front end, leaving my amps to "drink from the tap," due to the obvious constraints. Not as elegantly styled as the PS audio and others, but sounds worth a try!
Having heard the 47 Labs and the Final products together I can say that they did not blow the 47 labs out of the water. Anyone who wants to buy 35 bateries every few months has a problem anyway. The build quality is not too good either. The Rowland battery supply? I wonder how long Roland will make it availabel?
I don't know about the other amps mentioned, but the N.E.W. amps had re-chargeable batteries. Plug them in after your listening session and you are ready for the next round, I agree that buying 35 batteries is a bit weird...
I wonder if there is anyone who has had experience with the N.E.W. in an owners perspective. I know it sound weird to have 35 run of the mill batteries powering an amp and 20+ other same type batteries running the preamp, nevertheless, I wonder if running tubes and class A amps, which do make a dent in the wallet as the environment as would the wasted batteries be on the same league....It is simply a different way of spending our greenbacks. I have read in the Final company website that if one listens to the stereo set up, 2 hours a day with fairly efficient speakers (96db+) the set would last about 6 months. I calculate the expense in batteries to be about a max of $100 to load a set, $100 in 6 months does not seem so reasonable. Let us think about all the insane amounts of money people spend in REFERENCE type powercords...some at 2k each!
The N.E.W. amp that I own is the DCA-66. Its very clear and a bit revealing. It doesnt sound like 60 watts. The pure current available to it gives it an very imposing sense of power. Almost scary. It slams out the power. Its good for about 4 hours. Then it needs an overnight for the 4 motorcycle batteries. Not likely to ever be duplicated. Quite a piece.
I also owned the NEW amp. It sounded great, battery lasted 4 hr's without charge. BIG PROBLEM! Reliability. Build quality and parts mediocre. Assembeled by moron's. Both the original and replacement bit the dust in a cloud of smoke. BEWARE!
Paul, the only battery powered equipment I had was a DNM pre -- 15 years back. The power supply was a rechargable battery, officially always plugged into the socket (purists had advised otherwise). It was particularly silent by pre-amp standards of the time (and the money: affordable) and thereby clear-sounding. A later model, conventionally powered (the "6") sounded better though.. probably due to better quality components and superior design.
Speaking of accumulators, someone suggested I try a military grade, 36 amp bettery to power the whole system. Allegedly, such accumulators are successfully used in submarines! Haven't tried this yet...
Correct me if I am wrong but I believe the NEW amps were designed by Nelson Pass. I have heard that the design is good but reliability has something to be desired. I have never owned one so this is just hearsay.