Please help! Lights and batteries....what do i do?

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NetYetti

Joined: 15 Oct 2009
Posts: 4
Location: maryland

15 Oct 2009 22:22 Please help! Lights and batteries....what do i do?

Sorry for the possibly vague subject, I am new to all this. My problem....I am trying to do a romantic night with the lady friend and I want to run alot of lights in the middle of no where. No access to household power or generator etc... Can I run a string of christmas lights off of a car battery with an invertor? If so, how many lights and for how long? I dont know how to do the calculations so any advice would be useful.

The Lights i wish to use : Lowes Home Imp. Warehouse Item # 165147
100 ct clear mini lights.
uses 2.5v lights, 3 amp fuse (in the plug)
in the instructions it says "lighting is rated for 24watts (.2amps)
can connect strings end to end up to a
maximum of 210 watts (1.75amps) total"

I can try and get you more specific information if you tell me what i need to get. Just trying to see if this is a practical idea. Can i run 200 lights for 3 hours? or 500 lights for 10 minutes?.......i dont know where to start except id like to run about 400-500 lights for 2-3 hours. If you can tell me what id need equipment wise, thats what im looking for (a certain size car battery/invertor etc). Thanks again, i hope this post wasnt innapropriate for this site/forum. -Elliott

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unknot

Joined: 07 Oct 2009
Posts: 6
Location: Mars Base II

15 Oct 2009 23:40 Please help! Lights and batteries....what do i do?

i wpould connect them wireless.. the lamps ..with coil induction.. though the distance would be a problem.

NetYetti

Joined: 15 Oct 2009
Posts: 4
Location: maryland

16 Oct 2009 3:40 Re: Please help! Lights and batteries....what do i do?

Im not entirely sure what coil induction is (i have zero electronics know how) but the location really is going to be the middle of no where. Could be as much as a mile from any form of power. Some sort of battery is really going to be the only option.

cameo_2007

Joined: 15 Mar 2007
Posts: 439
Helped: 17
Location: 13.04°N80.17°E

16 Oct 2009 7:30 Re: Please help! Lights and batteries....what do i do?

wireless option is not going to work out.so forget about that.

this can be simply done with a fully charged car battery as you said,or any other battery like that of inverters or ups.
just check out what battery you could arrange, and find its specification.
the two important specifications:-
1) voltage (12V or 24V or)
2) Amps/hour

And now about the lights,the specification.
here again two main specifications:-
1) Voltage
2) Power consumption (in Watts or Amps)

now if you have these details,we can do a few simple calculations and arrive at your requirement.

cheers.

NetYetti

Joined: 15 Oct 2009
Posts: 4
Location: maryland

17 Oct 2009 4:28 Re: Please help! Lights and batteries....what do i do?

I appreciate you all helping with this, should be great when its set up.

Ok as per your last post....

1.The battery will in all likelyhood be a 12v car battery from Sears or someplace like that, I can pick out whatever you recommend. I was actually sorta waiting to see what you all think i should get before i commit to buying one. Tell me what will work best and thats what i will use.

2.For the lights, I do have those numbers i believe. I have 2 options for lights, standard string xmas lights and also energy saver L.E.D lights.The standard lights are in strings that are 24Watts (.2amp). The LED lights, all it said on the box was 6.4 Watts and did not mention what the Amp rating was.

If you need anything more specific let me know, thanks again

betwixt

Joined: 04 Jul 2009
Posts: 384
Helped: 62
Location: Wales, UK

17 Oct 2009 9:31 Re: Please help! Lights and batteries....what do i do?

All you are aiming to do is make a portable temporary mains electricity supply so you can use mains operated lights.

Battery - bigger ones will keep the power flowing for longer. Deep discharge types are preferable to normal car types as they will withstand going completely empty more times than standard car ones. Having said that, you are probably still looking at years of use on a standard one.

Inverter - this is the box that converts your battery voltage to 115 / 230V. Usually it will have two thick wires with clips to hook up to the battery, a power switch and a mains outlet socket. You can use extension socket blocks if you need more outlets.

The ratings - Your lights draw very little power but obviously, the battery will last longer if you use less. Any inverter rated more than your total load (all the Watts of all the light strings added together) will do. Most inverters are rated at 300W or more. A 300W one would power 12 of your normal light strings (288W total) or 46 of the LED strings (294W), that's an awful lot of lights!!

How long it will last - the exact figure will depend on many factors but you can make a rough calculation from the battery Amp-Hour rating which should be on it's specification. The rating means it can supply that many Amps for that many hours. For example, a 50AH battery could supply 50A for 1 hour or 25A for two hours or 1A for 50 hours. So what you need to know is how many Amps the inverter is going to draw, then you can estimate how long the battery will hold out.
The formula, at it's simplest is Watts/Volts so for example one LED chain would draw 6.4/12 = 0.53A and a 50AH battery would last 50/0.53 = 94 hours. That assumes everything is 100% efficient and in the real World it isn't so half that figure to be safe. You can still do a lot of romantic things in 47 hours Very Happy

Aren't you supposed to use candles though ??

Brian.

NetYetti

Joined: 15 Oct 2009
Posts: 4
Location: maryland

24 Oct 2009 4:47 Re: Please help! Lights and batteries....what do i do?

Thank you all so much, Sorry it took so long to post back. I think i have enough information to get something done now. And yes, candles would be the normal thing to use but i dont think it would be as romantic trying to explain to the fire marshall as to how 20 acres of woods are no longer there. Thanks again-Elliott

Audioguru

Joined: 19 Jan 2008
Posts: 1144
Helped: 93
Location: Toronto area of Canada

25 Oct 2009 1:21 Re: Please help! Lights and batteries....what do i do?

betwixt wrote:

How long it will last - the exact figure will depend on many factors but you can make a rough calculation from the battery Amp-Hour rating which should be on it's specification. The rating means it can supply that many Amps for that many hours. For example, a 50AH battery could supply 50A for 1 hour or 25A for two hours or 1A for 50 hours.

No.
An old fashioned lead-acid 50Ah battery is rated at the 20 hour rate which is only 2.5A for 20 hours. It might deliver 50A for a couple of minutes.