Found a neat thing for lighting purposes

Marcus Marchesseault · April 5th, 2008, 02:49 PM

Tim, you are right on the money. I really don't like the way battery manufacturers use "Amp Hours" as a measure of the storage capacity. They should use Watt hours since Watts are the measure of energy. Amps are really for measuring circuit capacity since they are a product of volts and watts.

"Marcus is dead on with the 27 minute calculation."

George did the math based on 51 Amp Hours and I cut it to a third or half due to the way high loads decrease the total output of a battery. I say no more than 15 minutes with two 650W fresnels on this battery. Switch to lower wattage lights and you will get the full draw.

Chris Leong · April 19th, 2008, 05:30 AM

BTW don't forget the lowly computer UPSs. I've used them on location before to power instruments (don't forget a hand truck - those little suckers are heavy!) - various capacities available, and when it's time for post you can stick them back under your desks. Frys or any stationery/office supply store, which makes them even more useful in the event a small genny packs up...

April 19th, 2008, 05:30 AM	#17
Chris Leong Major Player Join Date: Mar 2005 Location: Los Angeles CA USA Posts: 507	BTW don't forget the lowly computer UPSs. I've used them on location before to power instruments (don't forget a hand truck - those little suckers are heavy!) - various capacities available, and when it's time for post you can stick them back under your desks. Frys or any stationery/office supply store, which makes them even more useful in the event a small genny packs up... __________________ "The content, not the container."

April 5th, 2008, 02:49 PM	#16
Marcus Marchesseault Trustee Join Date: Nov 2005 Location: Honolulu, HI Posts: 1,961	Tim, you are right on the money. I really don't like the way battery manufacturers use "Amp Hours" as a measure of the storage capacity. They should use Watt hours since Watts are the measure of energy. Amps are really for measuring circuit capacity since they are a product of volts and watts. "Marcus is dead on with the 27 minute calculation." George did the math based on 51 Amp Hours and I cut it to a third or half due to the way high loads decrease the total output of a battery. I say no more than 15 minutes with two 650W fresnels on this battery. Switch to lower wattage lights and you will get the full draw.