12v Lighting

Has anyone installed 12v or 24v lighting in their house?

I have been looking into recessed lighting for our new house and want to get some but also add 12v recessed lighting as well.

Why? If someone's in the crawl space might as well add them, cost is in the labor to get them out doing the job, the lights are cheap and install QUICK. (I may even install them all).

Also, at night if we don't have power I'd like to turn-off the generator and still be able to switch on some lights to see

I also figure if we run the backup generator most of the time there will be plenty of extra power (even at half speed / idle) to charge a bank of 12v batteries, and rather than convert them back to 120 might as well take full benefit of the 12v (or 24v not 100% sure which way to go yet).

So, I know they make 12v CFLs and am curious if anyone has any they prefer? I know like normal CFL there must be good and bad ones out there.

-Todd

I would look for 12-volt LED lights (or make them by gutting flashlights) rather then CFL. LEDs use even less electricity then CFLs. If your objective is to reduce power consumption, LEDs will do it more then CFL will.

But they will also give less light. TNSTAAFL




It’s hard to find 12-volt flashlight heads (the LEDs themselves) but quite common to find 6-volt flashlight heads. These could be used with a cell phone 12-volt cigarette lighter charger. Most cell phones run on 5.2 volts, this is perfect for 6’volt LEDs. As all chargers are just a bit over-ranged in voltage.

You can find these chargers at garage sales all the time for $1.00 I have lots of them I have bought and save for projects.

I gutted a table lamp and turned it into a 6-volt battery powered light. I also made it so it runs off a wall charger (an old cell phone charger) and a 12-volt cigarette charger. Here is the thread of the project, it explains some about how it was done.




http://forums.equipped.org/ubbthreads.php?ubb=showflat&Main=11482&Number=139520#Post139520

If you do this, make sure you lay in a supply of extra lights so you can replace them if they burn out.

CFL or LED it doesn't matter as long as I can see.

The point isn't to reduce energy the point is to run with no generator or city power when the power goes out directly off my battery bank w/no inverter needed.

This way, I don't need an inverter... EVER. Generator for big stuff, batteries for lights.

I want to use standard fixtures wire them for 12v, and use the correct bulbs, so thus my question/search for quality 12v CFL or Leds, etc
-Todd

Also need to investigate 24v vs 12v and GOOD batteries to use I`m pretty sure 2 or 3 12v car-size batteries would be enough for lights from dark to morning w/occasional usage

Todd, that's on my to-do list. I've accumulated the bits and pieces (PV panels, batteries, charge controller, and 30 Luxeon 1 LEDs) but haven't had time to put it all together.

Strongly recommend you check out http://www.candlepowerforums.com/vb/forumdisplay.php?s=cb1ab5f4b1cef75db894f137417ba4ce&f=89 . Go back a year or more. There are people who have done it, with photos and descriptions in detail.

I would go with 2 6-volt golf cart batteries, they can handle being drained of power, normal car batteries can’t.

Also I would keep any lead acid battery outside as they give off explosive gas when charged. If you are going to put them inside use gel-cells or AGM batteries. They don’t give off gas. But they really need a charge controller as they can’t handle being over charged.

Wow, thanks I didn't know CPF had a "Fixed Fixtures" forum! Awesome!

Bos- I don't think 6v golf cart batteries would last more than a year or two? Do you know?

And as far as storage... I`m thinking the basement which is not finished and gets decent air flow.

-Todd

Take a look here for lots of good info on batteries.



http://www.phrannie.org/battery.html







As far as batteries go Golf cart batteries come out on top for power delivered. But they are heavy and large. I would not store them in a basement, charging lead acid batteries generates hydrogen gas (can you say Hindenburg?)

They make special caps that greatly reduce this venting, but hydrogen is some nasty stuff to have floating around in your home so I would not trust them. Do you have a gas or propane water heater? If so it’s even more dangerous to have batteries in a basement.

AGM batteries are the best for use if you are going to store them inside your home, but they are expensive and have to have a special charger (expensive) made for them so you don’t over charge them or charge them at too high of an amperage.

Thats basically the route I'm going, switch as much gear to 12v as I can so I eleiminate extra wiring and complexity and have the ability to use it while traveling.

There are plenty of automotive lights tht work just fine and can be bought cheaply in parts stores, junk yards, catlogs, etc and then you can swap the bulbs for led's if you want.

There are whole catalogs such as http://www.truck-lite.com/wcsstore/tl/splash.html (napa stores can order those in for you)

Check with the RV crowd - they have been doing 12 volt lighting and a bunch of electrical based on what you are thinking for years. If you have a big RV store close, they will have lots of 12 volt fixtures, lights, wires etc. You will also find a lot of good information. Be nice to the service guys and they can give you a bunch of tips too!

There are also some very good reference books on 12 volt electrical in RV supply stores and also marine supply stores for the bigger boats.

Paul -

One caveot on the Rv stuff though, I find much of it to be very cheaply made. You have grandma and grandpa living on SSI in their RV so they can see the country and they don't have a lot of $$ to spend so you tend to get a lot of cheap chinese import stuff.

"...you tend to get a lot of cheap chinese import stuff..."

Most RV stuff may be cheaply constructed, but it isn't "cheap." This I know for a fact.

Campingworld has some LED lighting stuff. Most is designed to be wireless, running off of AA batteries, but you might be able to do a re-wire into a DC system I guess...

yea, sorry, cheap as in quality, usually overpriced for the quality as well.
Thats why I prefer the standard automotive stuff. I have the cap of my truck setup for camping with dome lights from vans and suv's, light weight, and decent quality for $5 on ebay.

Hi ToddW

http://www.dealextreme.com/details.dx/sku.13842

You would probably need about 4-6 per room.

These are MR16 replacements for 12V Halogen lighting systems that have a mains 120-240V 60Hz US or 240V 50Hz UK to 12V DC power supply.

Many of Halogen 12 volt systems will use a 120-240V 60Hz US or 240V 50Hz UK to 12 volts 'AC' transformer instead.

You will need a single high reliability 120-240AC 50-60Hz to 12V DC power supply convertor if you intend to power the LEDs directly from the mains electricity. Typically the power requirement would be a 200W 12V high efficiency switching regulated DC power supply to power the whole domestic 12V lighting circuits (enough to power about 60 LEDs).

If using solar PV and battery bank then a solar charger such as the Steca PR1010 Solar Charge Controller will provide DC regulation for your 12V lighting project.

http://www.alternativeenergystore.co.uk/..._Controller.htm

You should then be able to use standard MR16 light fittings with these high effieciency LED Halogen replacements. You should also be able to use the existing wiring that is already in place despite it being a DC system using these lower power rated LED type replacement. You do need to be careful though as domestic lighting wiring may use only 1.0 mm diameter copper wire cable. This will give a resistance of 0.02 ohms per metre length. This may no sound like a lot but if the cable run is say 40 metres or 135 feet in length and the DC current drawn is 5 amps (i.e 20 of these MR16 LEDs turned on) then the voltage drop will be 3.9 Volts with nearly 20 Watts being dissapated by the wiring. With a 4V drop your MR16 LEDs may not come on. You need to make some estimates of cable run lengths and the power requirements of the overall design of your domestic 12V DC lighting system.

Once you have designed and accounted for the all the 12V DC wiring losses (as in the above example 20 Watts is lost for 60W power delivered) it might be worthwhile comparing the design against using 85-260V GU10s LEDs such as these.

http://www.dealextreme.com/details.dx/sku.13452

and by using a 12v - 120 or 240V inverter at the Solar PV Battery power supply instead and comparing the overall efficiency of the AC-DC and the DC-AC systems. Of course if the mains electricity is used then this is the simplest of high efficiency energy lighting installations.

It could be that the inverter system wins out in terms of cost and effort of implementation especially if the 12V DC system requires replacement thicker copper wiring to be installed to be competative.

Am_Fear_Liath_Mor - Holy smokes! THANKS!

Provided a charge controller is used to prevent overcharging, I would not worry about placing the battery indoors.
The amount of hydrogen emitted is very small and most unlikely to be a hazard, provided smoking, sparks and open flames are kept away from the battery.
Remember that until very recently, electric wheelchairs used vented lead acid batteries, these were normally charged and used indoors, also many garages are used as workshops without the vehicle battery being considred a risk.

Standard car batteries are not suited to regular deep discharge, golf cart batteries would indeed be far more suitable.

I would use 12 volts, not 24 since a greater range of lamps are available.
Remember that you may need to oversize the wires compared to a 120 volt circuit since voltage drop would otherwise be a problem.
I suggest a minimum of #12 wire on a 10 amp fuse, it would be prudent to install at least two circuits.
12 volt compact flourescent lamps and LED lamps have about the same efficiency, but the LEDS are generally available in smaller wattages.

If your going to do 12v lighting stuff order automotive wiring (waytekwire.com for example), the resistance is less there and therefore less loss. Unless your running from one end of the house to another then you won't really need to worry about the loss on automotive wire. Using 120v wire for 12v stuff is where you have the most loss, it typically has a higher dc resistance because its designed for a lower impedance (impedance is basically resiatance for AC).
There are also plenty of charts on the internet where you can look up the proper size for length and current.

I'm not an electrical engineer, I just play one at work. I'm not sure where you got your info on the impedance of household AC wiring, but I have to disagree. So long as they are all made out of the same copper in the same AWG, Romex, automotive, whatever wire will all have the same DC resistance.

But as you say, tables can be found online.

solid vs stranded. automotive wiring is always staranded and the copper in wall is solid. I've found the losses to be different when tesing the two.

I would be very suprised if there was any noticable difference in voltage drop between stranded and solid core wire, presuming of course that the sizes were the same.

#12 AWG is #12 regardless of solid or stranded construction.

For a permanently installed 12 volt lighting circuit I would use standard house wiring cable, but a least one size larger than useual to reduce voltage drop.
Remember that a loss of one volt is trivial at 120 volts, but is nearly 8% of a 12 volt supply.

It is unlikely that vehicle wire will comply with the NEC for domestic installation.

Thanks for the info guys I`ll ask some friends about regulations and being sure to stay within code.

-Todd

You might consider evaluating Nickel Iron batteries rather than Lead acid batteries.

Nickel Iron has a lower surge power capability -- which is why the auto industry selected Lead acid -- but Nickel Iron is much more forgiving of deep discharge and improper charging.

And they don't off gas Hydrogen...

Thanks, I`ll check that out.

A little electricity 101.

With a 12 v system you need heavier duty wiring. Reason power equals voltage times current. As voltage goes down current goes up. For those mechanically inclined think of a hose. To pass more water you need a bigger hose.

Stranded verses solid wire. Electrical current actually passes along the outer edges of a wire. Above a certain level of current stranded wire if more efficient for the same size wire. For a simple lighting system it really wouldn't matter. But there is an actual difference.

Dolf cart batteries are what are called deep cycle batteries. They are designed to operate at a slow long term discharge rather than a high surge. Car batteries are made to supply a large surge to start a car. Deep cycle one are what you want for a power system. They will last much longer.

Hydrogen and charging. You are going to get it. But it is easy to deal with. Either put the batteries in a sealed room or containers. Think Rubbermaid totes. One not big enough. Use as many as you need. Drill holes to pass the wires through. Seal the holes with caulk or silicone. Run a sealed pipe to the outside.

Stranded wire is used for one reason in autos and mobile applications, it’s flexible and will not break as easily as a solid core wire. It can take bending and vibration better. The power handling ability of one over the other never comes into play as all that is done to handle more power is to go with a bigger wire, not to pick solid or stranded over the other because it takes more current.

Thinking about this I don’t think a sealed pipe will do much. Without airflow (an exchange of air with in and outgoing venting) the gas generated will not go anyplace.

Lead acid batteries should be outside; hydrogen is just too dangerous to be in the living area of a home.

The front compartment of our home on wheel is the storage location for the house batteries. They came in a plastic battery box with a screened hole in the bottom, and a sealed flexible hose from the top to an outside vent. Airflow...

Hydrogen is lighter than air. Even in a closed system it will rise up the vent pipe. But vent holes at the bottom would help.

<--- Thinking what can I do with hydrogen that is useful...

With Hydrogen gas going up the tube where is the air coming in? it’s not because you need 2 openings.

Not without an exchange of air. It’s like a straw you dip in a glass of water. You put the straw in the water then put your thumb over the top opening and lift it out. The water will not fall out of the straw till you open the top of the straw by taking your thumb off.

It’s the same way with the gas the battery is venting. Unless you have air flow with 2 openings so the air can flow Hydrogen gas will build up.

One opening equals no exchange of air or in this case Hydrogen.

This is dangerous as Hydrogen can ignite easily with any kind of spark or flame.

So, my new house... it already has an entire 12v system!!! I found out when I removed drywall downstairs re-doing a closet!! One thing was marked 12v one was marked 110. I also found out when I started removing light fixtures and some of hte bulbs said '12v'.

So in every room that house a 110v light there is a 12v next to it Wahooo!

I need to find out where he planned/stored his batteries or if he just used the generator and converter to run 12v.

This is awesome! I`m so excited.
Heat will be wood and propane (soon), generator can run the well, hot water propane, lights 110 or 12v,... we can go a month or so w/out power LOL Saweet!

I'd take that as a sign the Universe is giving you a big thumbs up.

Looking forward to following your path.
-Blast

Stranded wire vs solid: DC electricity travels through the center of a conductor. As the frequency increases, it tends to move twords the surface until at very high frequencies it travels on the surface.

However flexibility becomes an issue in a moving enviroment (aircraft, boats, RV's etc.). If solid wire is used here, it will eventually break from vibration flexing.

Lighting: Most filament lights are very inefficient. The newer LED lights are very efficient, but the light is still not up to all applications. We use compact florescent lights for applications where lots of light is needed. We get the cheapies from W-M and use an inverter. Works great. 100 watts of light (equivalent) takes 380ma, about 24 watts of power.

Hydrogen Gassing: The best method of venting is to use two concentric tubes at the top of the container. There are good diagrams on the web (sorry I don't have a URL) that explain the concept. It might have been on a Concord Lifeline Battery site.

Battery Gassing: Not all batteries vent gas during normal operation. AGM batteries use a catalyst to return the gas to a liquid state avoiding the release of hydrogen in all but the most extreme overcharging situation. They require no vent if the overcharging situation can be prevented by proper system design.

Been living off batteries and 12v for about 11 years now.

Nomad

Blast - Me too! Hehe, I won't have time to get back to 12v system until the plumbing is fixed.


Cool info Nomad thanks

Home Depot had 60w CFLs on sale for $2.88 for a 4 pack!! I think a power company sponsored or something... I bought a bunch (110v) for that price, they were name brand too not the generic off-color, low-light cheap ones!

-Todd