# How Long Should They Burn?



## big rockpile (Feb 24, 2003)

Wanting to use couple of these Lights.How long shout they burn off a 12v 75 Amp Hour Marine Deep Cycle Battery?

Web Store - Custom Fitz L.E.D. and H.I.D. lighting

big rockpile


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## AVanarts (Jan 2, 2011)

OK, 12 volts times 75 amp hours gives you 900 watt hours.

You probably shouldn't discharge that battery beyond 50% to keep a decent lifetime, so 450 useable watt hours. 

The light uses 50 watts, so 450 watt hours divided by 50 watts will give you 9 hours of light. That's assuming one light and one battery.


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## tkrabec (Mar 12, 2003)

Ideally you want to use less than 20% of the battery's capacity for longevity, ie the more you discharge a bettery the less often you can charge it. Also don't forget to take into account inefficiencies. so figure 8-8.5 hrs using AVanarts figures.


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## big rockpile (Feb 24, 2003)

Ok I'm wanting to use two of these Lights for Gigging on my Boat,without using a generator.Most they would be used is 6 Hours a night.

My understanding is Deep Cycle Batteries develope a Memory so best to completly draw them down before recharging.I'm thinking LED Lights will draw less.

Either way if I get couple of these Lights and maybe couple Batteries will be far cheaper than Buying and Running a Generator.

big rockpile


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## AVanarts (Jan 2, 2011)

Lead acid batteries don't develope a memory so there's no problem there. The old Ni/Cad batteries that were used in cordless phones and stuff like that did develope a memory, but I haven't even seen those in a while.


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## fantasymaker (Aug 28, 2005)

Led are not real efficant Id go for a inverter and CFLs in the Daylight not the soft whites.
Menards here has a 3 pack of 60 watt equivilents for 99cents a pack!


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## Jim-mi (May 15, 2002)

I have to disagree with the last post. 
LED's are very efficient.
What about the inefficiency of the inverter....
And since this is for fishing it is far safer to keep it at 12vdc rather than water/120vac hazards.
With a 12vdc LED lamp you could even let the lamp go totally under water--Safely.

Those ultra cheap CFLs are what gives CFLs a bad name ----short life cheap......

Ya get what ya pay for . . . . . . .cheaper is not always better..........


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