# 300W 220V Light Bulb on 12v DC?

#### pixer

Joined Sep 20, 2017
11
Hi,

I have read different posts and opinions about how to power up a 220v Light bulb with a 12v DC Acid Lead battery. I am still confused about the practical way to do that.

I am asking any good advice to how one can power up a full spectrum daylight bulb which is 300w and runs on 220v AC, with a 12v DC Acid Lead battery (or higher like 24v or transfomateor etc) ?

All tips will be appreciated.

#### Papabravo

Joined Feb 24, 2006
16,783
Using something in a fashion it was not designed for is usually a fool's errand. Why is that the case? Well, let us assume that you wish to achieve the same level of power delivered to the bulb so that you will have the same level of illumination. So 300 Watts. If you just connect +12VDC across the bulb you might find that the resistance is so high that it fails to heat up and just glows dimly. In other words it does not light up bigly. Aha, you think, how about a DC to DC converter to boost +12 Volts to +220 VDC. To get 300 Watts output with a converter that is 80% efficient requires 375 Watts of input power from the battery or 31.25 Amperes. A typical automotive battery can supply huge amounts of current for about 30 seconds and then it is dead and needs to be recharged. OK, you say, how about a +12VDC to 220VAC inverter and we are looking at basically the same power equation. Whatever we do the battery is unlikely to have sufficient capacity to keep the light lit for very long before needing a recharge. If you have access to the AC mains for recharging the battery why not just run the bulb off of them?

As much as you want there to be a convenient solution, I'm afraid it will remain elusive, unless you are familiar with wizardly wonders.

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Joined Jan 15, 2015
6,059
The problem here is exactly as Papabravo explained. Three hundred watts is just that, three hundred watts. Three hundred watts at 220 volts becomes 300 / 220 = 1.37 Amps but that same 300 Watts at 12 volts becomes 300 / 12 = 25 Amps. If the need exist using either a 12 volt or 24 volt inverter is a viable solution as long as the voltage sorce can provide the needed current for the needed time. Going to a 24 volt battery will half the current which would be required of a 12 volt battery source. Those numbers also, as Papabravo covered, do not take into consideration efficiency of an inverter. The end result is power is power.

Ron

#### philba

Joined Aug 17, 2017
960
What I heard is you need this light run off of a battery. Unless you absolutely must have the exact specific light, why not look for an LED bulb with the similar characteristics? You could power an LED lighting solution from an inverter with 1/6 the current or less. Depending on what your "full spectrum" needs are, look at MR16 LEDs with a CRI of > 90. 4 to 8 of them together will make for "equivalent wattage" and pull a lot less.

An example: This bulb pulls 7.5 Watts and runs off 12V (7.5/12 = 625 mA) and has a CRI of 95. 6 of them are "equivalent" of a 300W incandescent.bulb. I put it in quotes because using wattage for lighting is pretty inexact, do you know your actual lumen or candella requirements? That would pull 3.75 Amps, feasible with a lead-acid battery, maybe even a big 3 cell Li-ion battery.

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#### pixer

Joined Sep 20, 2017
11
What I heard is you need this light run off of a battery. Unless you absolutely must have the exact specific light, why not look for an LED bulb with the similar characteristics? You could power an LED lighting solution from an inverter with 1/6 the current or less. Depending on what your "full spectrum" needs are, look at MR16 LEDs with a CRI of > 90. 4 to 8 of them together will make for "equivalent wattage" and pull a lot less.

An example: This bulb pulls 7.5 Watts and runs off 12V (7.5/12 = 625 mA) and has a CRI of 95. 6 of them are "equivalent" of a 300W incandescent.bulb. I put it in quotes because using wattage for lighting is pretty inexact, do you know your actual lumen or candella requirements? That would pull 3.75 Amps, feasible with a lead-acid battery, maybe even a big 3 cell Li-ion battery.

#### pixer

Joined Sep 20, 2017
11
Thanks for all the replies guys, all good conciderations!

Philba:

The reason for my post is a little special.
I suffer from something called EMF sensitivity, meaning my health is negatively affected by wireless electromagnetic radiation like cell phones, wifi etc, but also the AC current of the 220v power grid.

I can use low voltage dc power without getting health issues.
I use this full spectrum therapy light bulb, called OSRAM Vitalux 300w.
It works like a mini sun, and can make the skin produce Vitamin D after exposure.

Even when it is powered on 220V AC (which I get issues with) it sill gives me a good effect in terms of well being and producing Vitamin D.
Then I thought the ideal for me would make this "healing" light bulb run on 12v DC.

So if your full spectrum MR16 LED could also work as this it would be awesome.
Here is a link to the OSRAM Vitalux
https://www.amazon.com/ULTRA-VITALUX-OSRAM-MEDICAL-TANNING/dp/B003XVSWP8

Would you still think that 6 of the MR16 could be powered up and come close to the Vitalux?

#### bertus

Joined Apr 5, 2008
21,532
Hello,

As the shown bulb ia a tanning bulb, it will contain a fast amount of UV.
The led lamp likely will have far less UV.
Is tanning what you want to do?

Bertus

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#### philba

Joined Aug 17, 2017
960
Yeah, not a lot of UV-B (which is what I believe the TS wants) in those MR16 bulbs.

There are UV LEDs though this is starting to become a research project. You could mix UV LEDs into the array to get the specturm you want. I have no idea what the UV LEDs produce. There are LED grow lights that claim UV-B, maybe that's a solution.

#### pixer

Joined Sep 20, 2017
11
I wonder if it would be possible to contact someone here on these forums to help me build a LED UV panel like this. Does anyone know or have tips how I could post a thread and ask if someone has the engineer skill to build a panel like this if I buy and order all the parts needed, and they just do the job? I could pay them for the work hours etc.

ANyone have tips for persons here to contact or that does things like that?

#### Externet

Joined Nov 29, 2005
1,654

#### andrewmm

Joined Feb 25, 2011
1,751
aproaching this from the other end,

I know nothing apart form what I have just read on the web about EMF sensitivity.

But,

Have you tried shielding the light source , so light gets through but the EMF is blocked ,

the wavelength of the UV is very different to any EMF,
so was wondering about a metalic gauze screen,

also thinking abstract, would a SAD light be appropriate, I have seen LED versions of these. Though no UVB , so one would still need to take vit D tablets,

Joined Jan 15, 2015
6,059
I suffer from something called EMF sensitivity, meaning my health is negatively affected by wireless electromagnetic radiation like cell phones, wifi etc, but also the AC current of the 220v power grid.
With that in mind an incandescent lamp having a filament will not care if it is run on an AC or DC supply. At some point set up your AC to DC conversion of the voltage of your choosing and run your illumination off DC.

Normally around January or February I have a doctor visit. I live in Cleveland, Ohio where winter is cold, grey and dreary. Generally by January or February time frame half the population is borderline manic depressant. While I never get that way my doctor does give me Vitamin D which is pretty common. They do the normal blood draw and see the deficiency and I take a single simple pill once a week for a few weeks and done.

Ron

#### philba

Joined Aug 17, 2017
960