QuoteQuestion for Electronic Wizard
If I take 2 60 watt light bulbs that run on 12 volts and have a 50 amp regular fully charged car battery
How long would those bulbs light?
Thanks :D
12v * 50 a = 600 watts / 120 watts = 5 hours.
But the last hour wil be getting dimmer and dimmer
Change the bulbs to LEDS if you want staying power.
I agree with deuem.usually though.unplug the battery after five hours and let it set a while.there will be some residual to use .
Its some time since I thought about Electrical....working out of Power, Volt Current Formula's.
Would this be correct
Power (P) (Watts) = Voltage (Volts) (V) X Current (Amps) (I)
P = V X I or P = ( Volts X Amps )
600 (Watts) = 12 V X 50 Amps
Each Light Bulb = 60 Watts
Total Power of Bulbs If in series = 2 x 60 Watts = 120 Watts.
Total Power of Battery = 600 watts / power used in 2 bulbs = 120 Watts
Time Bulbs will last = Total Power Of Battery / Power used in 2 bulbs.
5 hrs = 600 Watts / 120 watts
From Ohms Law ...
where R = Resistance in Ohms...
V = IXR
I = V/R
R = V/I
I dont mess w ohms law much but i think thats correct.the power stuff is correct.
Quote from: zorgon on February 13, 2014, 02:41:29 AM
If I take 2 60 watt light bulbs that run on 12 volts and have a 50 amp regular fully charged car battery
Is that 50 A/h?
5 hours, correct, probably 10 if both your bateries are 50AH each.
You can multiply that 5 times using a switching circuit like the 'overunity cap' circuit i posted.
There will be more on that later, soon as i finish up a few things ;)
Quote from: deuem on February 13, 2014, 02:47:38 AM
Change the bulbs to LEDS if you want staying power.
5 hours crap I guess I will have to go LED but they are harsh white Maybe I can put a filter over top to diffuse the light
So lemme ask ya this....
what would I need in LEDs to get the equivalent lighting of two 60 watt bulbs?
I need to light a tent at night for shoppers and don't want to mess with propane this time
:D
I would use compact 12v CFL's like they use in campers & emergency exit signs.
I dig them out of old scanners all the time, tube, circuit, that's it. Most of them are 6-18v so they work fine ;)
DC 12V 15W CFL Light Bulb Lamp 2700k Solar Boat Marine RV Compact Fluorescent
- 90 Lumens - Equivalent to 50W incandescent bulb
- Color Temperature - 2700k - Warm White
- Works with any DC 12V Battery or DC 12V power source
- Great for Use with Solar panels and Systems
(http://img.auctiva.com/imgdata/0/7/0/3/8/0/webimg/194733134_tp.jpg)
Those may work :D There is power at the food vendor area so I could run a charger during the day. I only need the light for about 3 hours a day
I have a week to figure it out :D
what about camping laterns?....batteries, lamp oil , etc..
or those led thingies you can stick in closets ..
just thinking
A small quiet generator? 8)
z, no matter what lights you use, just remember you have 600 watts sitting in the battery, how you spend that 600 is up to you, 12v * 50 a = 600Watts
On your new 12 v 15w bulb use 600w/15w = 40 hours,, 2 bulbs 20 hours , 3 bulbs 13 hours, 4 bulbs 10 hours. So 4 bulbs at equal to 50w = lux of 200watts vs 2 @ 60w or 120 w. Like adding a third bulb for free and more left over.
I say go with 4 bulbs and you should be happy and last all day, 10 hours. If it is too bright in the day time, unscrew a few and wait for night time, Afterall 1 should go 40 hours or almost 2 days non-stop./
The leds are the best and safest.you dont want a cfl busting by accident.leds are way more efficient than anything else on the market.i have an led headlamp that i use almost every night for one hour and i only charge the thre triple a's like once a month.if the lite is too harsh then point it at the tent surface and it will diffuse and give a warm glow.or get a multi colored one.like with a few blues and reds mixed in with it .like the plant types.
You could run a whole week probably on a car battery.