Practically Audioroot can squeeze more power into their batteries. They offer a 37 watthour and an 89 watthour, I had two of the bigger ones to play with. Audioroot have left behind the NP1 shape for a Nintendo DS sized battery weighing 16.5 ounces. Yes, Audioroot have imperial dimensions on their website. Waterloo was not in vain. To give you some idea of capacity – my six channel Audio Developments fully loaded with phantom mics and two radio channels draws about 7 watts so a fully charged 89Wh battery will give over 12 hours or what most director’s believe can be achieved ‘before lunch’.So apart from some fancy chemistry, more power and a different shape what have Audioroot batteries ever done for us? Well these batteries are smart. Each battery has an on board chip that communicates with the outside world via smBus technology. So if you use one of Audioroot’s smBus enabled chargers – your battery will know how many cycles it has been through. It’s temperature and state of charge can be declared to the outside world and if all is working well then the operator will ‘know’ how much time they have left at the current rate of usage.
In order to access this information you need one of Audiroot’s external power distribution boxes. However ‘power distribution box’ does these devices a real disservice. The eSMART BG-DU is bit bigger than a box of Swan Vestas while the BG-DH is more Bryant and May sized. The BG-DU accepts a Hirose input and has 8 outputs. It has a colour oled screen which is daylight readable with a very fetching three colour fuel guage. On screen with one of their own batteries you get – percentage charge, current voltage to one decimal place, remaining time at current discharge rate, current draw, temperature, wattage being drawn and number of battery cycles. Even if you haven’t got an Audioroot battery the BG-DU is willing to learn. It can remember the capacity of up to eight batteries so pick a battery pick a number and with your battery fully charged connect all your kit and power up selecting ‘configuration’ mode. Keep an eye on the system voltage and when it reaches non safe point end configuration. Now the controller knows how much charge that battery holds all you have to do is tell it which battery you have connected when you power up and you get all that lovely info on state of charge.
Your might be smirking at bit at the estimated time left at current draw. Well running my aged Filmtech LSP4 plus a couple of phantom powered mics a brand new 89 Wh battery promised 21 hours 20 minutes. Six hours later it promised fifteen hours ten minutes. Thirteen and a half hours later the display showed six hours 50 minutes left. So far so good. Switch off overnight. Next day it powered up displaying five hours thirty minutes – a little light – but in the end recalculated and delivered six hours thirty minutes. A nice bright red led will flash when you get below ten percent capacity. There is a regulated version available with two 9v outputs for directly powering radio mic receivers.
If you don’t need eight outputs the eSmart BG comes with four, two of which are separately controlled from a locking front panel switch. You get the same info as the bigger box (but not the calibration facility for non Audioroot batteries), the input is a hard wired dedicated Audioroot cable assembly. And finally the vmDBOX a small digital voltmeter cum power distribution box with six outputs. This is designed to give you an accurate (two decimal places) voltmeter. The voltmeter consumes about 50 milliwatts which you should be able to spare.
As for chargers I had the portable one you might take on location which is a no frills affair and not smart and the two slot desk top charger which will update your batteries internal info. The desktop charger is simple to use fairly discrete and far too noisy. Change the fan monsieur root. While I’m in a critical vein, the BG’s outputs are not labelled and if I were designing a battery system from scratch I would have tried for a clever locking system on the battery end connector and maybe something a tad more substantial. Connecting batteries with less than 10% charge can confuse the state of charge sums, but that red led saves your blushes.
However these are nits and shouldn’t obscure the fact that the Audioroot battery system is a work of Gallic genius. Tonnes of power in the batteries, brilliant features on the boxes, and if you sat down and said, ‘what do I want my battery system to do?’, then Audioroot have answered the question in spades. C’est magnifique. Don’t sit next to me on a plane any time soon.