Any field tests yet?
Yes, I've actually taken the Omnicharge into the field for a few shows over the past month. Have been planning to do a write-up with my impressions so far and kept slipping my mind until now, my apologies. It's mostly good with some bad, so I'll get on with it: THE GOOD:
The build feels very solid and it has a nice heft to it. Weight is about 21.75 ounces and it's almost a perfect 5-inch square (4.75" x 5") with beveled corners, smooth edges, and just a hair over 1 inch thick. The display on the front is fairly clear (appears to be OLED) and intuitive but the font is on the small side.
It comes with a 19V / 2.37A wall-wart for charging that terminates in a pretty typical barrel connector, and the battery itself can be charged with any voltage from 4.5 up to 36 volts. I've successfully charged it with power adapters from Toshiba and Asus laptop computers. The wall adapter from an Edirol/Roland R-44 will fit it BUT since the R-44 has reverse polarity on the plug you would likely fry the battery or at least trip any protection circuits in it if you try to use it.
I splurged for the "DC Output" upgrade which makes the Omnicharge's charging port do double-duty as another power output in addition to the AC output and the twin USB outputs. It can be set via the menu from 1.0V up to 24.5V in 0.1V steps, and will ask you to confirm the voltage that you choose. One thing to note is that if you turn the Omnicharge off the DC output automatically turns itself completely off as well. When you turn the battery back on you have to go back into the menu to set the voltage of DC output and turn it back on. It does have a list of common presets and the last voltage setting you used. I wish they had put this much thought into the main power buttons on the front; more on that in the "BAD" section below. The DC output cable they sent (which they forgot to include in my initial shipment) is all but useless to me as the tip I requested doesn't appear to have quite the same measurements that they listed. Not a problem as it uses a standard barrel connector and I was able to rig up a cable in a matter of minutes with Adapt-A-Plug tips and other stuff I had on hand.
The voltage output is somewhat close to what you expect to come out. The AC plug output registers 133.7V on a multimeter which is high for the U.S. standard. The DC output is a little closer to true with 9V reading as 9.25 and 12V reading as 12.25 on a meter. The power itself seems pretty clean: running an R-44 and a few preamps at their lowest accepted voltage (9V), I can't hear any hum or whine through headphones plugged into these devices. I can't say that about the Tekkeon MP3300 which will cause a high-pitched whine at 9V into the R-44, and makes me run the MP3300 at 12V to avoid it.
In use, the Omnicharge gets fairly warm but not hot to the touch. I've run some devices that you could fry an egg on after a few hours and this battery hasn't come even close to that so far. The display actually shows the battery's temperature and I've yet to see it read over 101 F. This is after running several hours in my gearbag right next to my R-44. Keep in mind that this has been in music clubs at night where the ambient temperature is probably around 75 F (give or take) and not in the heat of the blazing sun during an all-day festival. Each of the times I've had the Omnicharge in the field, it's powered an R-44 for about 5 hours straight. With all 4 channels running, full phantom on two of them, after 5 hours the battery is down about a third (ie 33-35%). THE BAD:
The buttons on the face of the battery. My beef isn't with the implementation of the multi-function buttons, which is very straightforward and intuitive (one short press to power it on, two quick presses to access the menu, a long press to power it off; the AC/USB on-off rocker buttons to scroll through the menu), but is with how easy it is to trigger these buttons, which aren't recessed at all. The "short press" to power on is a fraction of a second, and the "long press" to power it down is barely over a second. The AC/USB on-off buttons have no delay at all and are instant-on, instant-off. Combine this with the fact that there is no way to lock any of these unprotected buttons and just the right amount of pressure against them in your gearbag could turn the battery off during a set you're recording. Not good. I haven't had that happen yet as I'm aware of the issue, but I think it's just a matter of time and bad luck before it does.
I did have the battery accidentally turn on while in my bag. Packed up after a show one night, made sure the battery (which still had over 30% of its charge left) and everything else was turned off, and went home. Didn't bother to unpack and check everything until the next day and found the Omnicharge was completely out of juice. It charged back up just fine and, through some experimenting, I found that on the underside of the lid of my gearbag there was something in the pocket hard enough to have pressed the power button while I was carrying it, I guess.
I reached out to Omnicharge customer support to see if there was any way to lock these buttons that I was unaware of, change the amount of time you have to press a button to trigger something, or if they could address any of this in a firmware update. Negative to all of the above with the further caveat that there's no way to update the firmware on the current model. They did appreciate the feedback and said that it will be passed on to the R&D team. To be honest, this issue is perilously borderline close to a deal-breaker for me and means that I'll have to be very careful or figure out some kind of failsafe when using this battery in the field.
To a lesser degree, the shape isn't quite what I'm used to using (Tekkeons, DVD player batteries, etc) and the Omnicharge doesn't fit my gearbag as well as I'd like. At worst, it's been merely a slight annoyance figuring out what arrangement in the bag works best.
Anyway, that's what I have so far. Other than the one glaring issue, I'm happy with the Omnicharge and intend to keep taking it into the field unless it does something to really piss me off, lol. If there are any questions, something you want me to test out, etc, feel free to post here. Thanks.