powering up LEDs with batteries

[Patryk_Rebisz]

I'm getting ready to invest in one or two LED 1x1 panels (to be decided which one) and i'm looking for portable power supply (V mount type batteries). Since i would only need the power supply for run-and-gun situations i was wondering what i should be looking for when looking up batteries specs? I assume the Wh is important as this is how long the light will run, the weight is important so that the G&E guy won't hate me for holding the light over the actor's face... What else?

I've identified a few brands:
Globalmediapro 160w ($260)
Ikan 130w ($340)
Switronix 130w ($350)
VariZoom 126w ($380)

Any opinions on the above?

Any help would be much appreciated.

 

[Norman99]

Hi Patryk.
Check out the upper voltage input limit to the lights you wish to buy. A limit of say 12 volts DC is not good for the V mounts that have a nominal 14.4 volts rated. Them V mounts can go as high or higher that 16.8 volts when fully charged. Specs that have an 18 volt or higher on the lights should be fine. Make sure you also get a dedicated or made for V mount battery charger as the V mounts require certain current levels and charge conditions as they surely have the li-ions (lithium ion batteries) in them.
A battery that is rated for 120 watt or watt/hour just meas that if your light draws say 40 watts, you may expect to see 3 hours use. The light units usually have that watt consumption figure on their spec sheets.
Some led panel units already have the V mount adaptability option directly behind the units if you wish.
Depending on the run time needed ( watts/hour), that should indicate the battery capacity by multiplying the voltage X the amp hour rating. ( ex. 14.4 volt X 9amp = 130 watt )
Led units in general have a much higher run time if you dim down a wee bit, so if you throttle down to say 80% on the dimmer, you may get more than twice the run time in most cases. It is a non linear lumens to watt thing.

 

[Patryk_Rebisz]

Thanks Norman!