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Portable lighting solution: Is it possible to power (400watt) Halogen light from a 12V Car Battery? Answered

Im trying to work out a cheap, portable way of lighting when on location whilst filming.

The idea of a generator is just to expensive to even think of at the moment, so is it possible to power (400watt) Halogen light from a 12V Car Battery?


Are there any readily available 12V lights that produce the same light as 400Watt halogens and above?

Thanking you much :) 



Best Answer 4 years ago

Simple math Current equals Watts divided by Volts

A = 400 / 12 => 34 Amps

Bot an 80% efficient inverter will need additional current to provide AC line voltage.

So we need to add 20% more current = 1.2 x lamp = 1.3 x 33.3 = 40 Amps

You need an 80 Amp-Hour 12Volt battery to run your Halogen Lamp for two hours !!!


That is only $220 for the battery so much more then LED lighting.

Now just buy a 1/2 KW inverter.....

LED parking area light with a fluorescent above the door.

57watt LED array


Here is a New Power 150 w LED lamp for warehouses that outperforms 600 watt halogen for 4 times less less electricity plus no bulb to replace for twenty years .


Yes, and no.

Yes, it can be used, but as a power source for a 400W lamp, it won't last very long before the voltage droops beyond a usable level, unless attached to an active charging source. (check the drain curves for standard lead-acid batteries) .

Standard lead-acid batteries used in automobiles really aren't suited for use as standalone power sources for high drain-current loads and expect a constant charging source while being depleted (aside from starting the motor). Failing to maintain a ~fully-charged state will result in permanent damage to the battery due to sulfation of the electrodes.

The problem with inverters (not sure why they were brought up) is that they are themselves a load, and they will simply accelerate depletion of the available charge.

I have a 12V car battery that I mistakenly replace on my automobile a few years ago (problem turned out to be an intermittent failure of the alternator) which I use as a 'storm outage power source', but when needed I only use it to power a small led lamp, a USB charging unit for my cell phone, and a "straight" dc output to drive a transistor radio. Total drain is ~ 1 amp. Works well enough for a few days to outlast the outage. 30+ amps sustained while maintaining the rated output voltage? not likely.

use the halogen bulbs that cars use for head lights just mount them in housing reflector from a shop light , will have to recharge after hour or mabey more but will work and If you look you may even find the 400 watt bulbs for a car


The problem I have found here is that the LED panels - even the large ones do not provide enough light to compete with a halogen bulb. In my experience with 30cm x 30cm LED panels, the light doesn't cast over the same length either.

Pros are using LEDs, you're not looking in the right places....

You could use an inverter from the battery, it would be moderately efficient, but what kind of run time did you want ? You MIGHT get a couple of hours from a single 100Ah battery.

That's basically on the lines I was thinking, but I always get lost on the Ah side of things - I struggle with V, W, Ah etc.
A couple of hours would be idea. What sort of inverter would I need? One that matched the load of the Halogens? Eg. a 400w bulb would require 400w (plus headroom, say 500w) inverter, then an additional 400w if I used more than one light from the same inverter? So to run two, 400w halogen bulbs I would need a 1000w inverter? - Or am i just loosing myself! :P haa