View Full Version : External power


Aaron Leung
June 27th, 2014, 10:10 AM
Hi all,

I am trying to power some lights outdoors at some remote location (with no ac power anywhere to be found). Any affordable recommendation in regards to how I could power lights that would take from 100w to 300w for up to 2 hours?

Any pointers appreciated.

-Aa

Greg Miller
June 29th, 2014, 11:17 AM
You're describing a situation requiring 600 watt-hours of capacity. I assume your lights need AC, since you mention lack of an AC source on site.

You could use an automotive battery (or, better yet, a deep-cycle marine-grade battery) and a solid state inverter. Let's assume, worst case, that the inverter is only 50% efficient. That means the battery needs to provide 1200 watt-hours. If you use a 12 volt battery, you need one that can provide 100 amps continuously for two hours. Give those requirements to a reputable battery supplier who really understands the different types of storage batteries and what the specifications actually mean (i.e. NOT your local WalMart, who can look up a vehicle and sell you the correct replacement, but doesn't likely understand all the technical details). Then make sure you get inverters with at least a 50% safety factor -- or, in the case of incandescent lights, which have a very high inrush current, 100% safety factor would be even better.

Do not turn on all the lights at the same time, turn them on one by one to limit the peak current consumption.

And you'll need an appropriate charger to recharge the battery when you're done with the day's shoot.

Doug Jensen
July 2nd, 2014, 02:19 PM
Get some LED lights. I can run my lights on batteries all day long, and I very rarely plug-in anymore even when there is power available. As an added bonus, most LED's are daylight balanced as well.
LED is your answer.