Using a Power Inverter to a Car Battery for Lights?

V

vision_filmz

Carbonite Member
Using a 1500 watt inverter.

I have in the past used my car battery to power a 1000 watt soft box with no problem. I would say I used it on and off for about 2 hours with my Car running where we had no way to get electricity. Now my question is this.


It looks like using a power inverter and car battery can cause problems because of the type of sign waves that are being used?
Also what do you think about me powering some Arri lights ( 350watt, 1000watt ) for a couple of hours using this same method?


I know about professional generators that are specifically for this, but working with no budget rite now and that is not an option.

Thanks
 
power inverter are usually low power (under 1000W) so you will hardly get any usueful light from so few power.
then there is 2 kind of bulbs, tungsten (incandescent) and fluo tubes. The first is very power ungry (lots of heat, more than light) but does not really care about the sin wave quality.
unfortunately these kind of lamp also ask a lot of current when starting cold.
the second type, (fluo tubes) produce a lot more of light for the same power (less heat) but is very finnicky about sin wave (frequency and shape) and creating lots of disturbance on the power line, so the final stage of your converter could just blow up.
My guess would be to go with small power inverters (about 500W) , one for each tungsten light (about 300w) , so you can get the choice to cut and add light and place it as per your need.
 
Or, of course, there is the option of using 12V bulbs. Since you didn't identify exactly what lights you are using, we don't know whether this is an option for you. But I can get 12V cables and 12V bulbs for some of my lights. That bypasses the whole issue of converting the power (which is never very efficient).
 
I tried already to use HID for car (kind of equivalent to HMI used for cinema).
these little bulbs offer a lot of light (but they get hot too) and are cheap.
There is a little box you need to connect to get the proper voltage (these light work on very high voltage and frequency), this could be and issue when using them under rain or with wireless audio.
Conclusion is , this is cheap enough to build an ultra portable kit, but there is some drawbacks.
First, they ask for some warm up and you need to be careful not to switch it on and off too fast.
Second, they get VERY hot, so it is always a concern.
Third, you need to carefully choose the color temperature, since the low color temp (White-yellowish is rare, you find more usually very high color temp , over 6000K, very blueish).
And the CRI (the amount of each color represented in the spectrum, with the sun being the reference) is not that good, meaning some colors could render a bit strange,
like yellow turning brown or green).
...and forth, the light is very hard, so you get razor sharp shadows, so a sanded glass is necessary to diffuse a bit.

You can find on ebay a pair of bulbs with electronic ballast for less than $100, so i think worth to try.
http://cgi.ebay.com/ebaymotors/9006...r_Truck_Parts_Accessories&hash=item27bde2e691

The idea is to build some caddy with a big 12V battery at the bottom, few feet of thick 12V cable and 2 aluminium stand.

Now i use fluocompact bulbs (requiring main power) with foldable (umbrella type) boxes.
These type of bulbs are very powerful (a 80W bulb is equivalent to a 400W lamp), they stay cool and the color is acceptable (if you take the daylight type http://www.ebay.com/itm/65W-Video-p...792?pt=LH_DefaultDomain_0&hash=item19c87abea0
at 4500K, the usual type 3200K is very yellowish).

If i really need to go in the field where no main power is available, i can still use one of these cheap chinese (ebay) up-converter (you can find 500W model for as low as $50).
The foldable box is from korea (Konova)
http://www.ebay.com/itm/CONTINUOUS-...644?pt=LH_DefaultDomain_0&hash=item1c1e8e0acc
and is ok for the price, come with a 4 bulbs adapter, so i can choose how much bulbs i need to screw in.
4 x 80W bulbs give me an equivalent of 1500W for less than 350W of power, and i also use 35W and 21W bulbs.
I am very happy with it, especially because the light is always soft, so turning it on generate desired light with almost no shadows to get rid of.
If you are looking for a no trouble - one fit all lighting, this is the best you can get.

I also tried LED panels, but while they are great for giving light from almost no power, if you need workable light level just from LED, the quantity and size
of panels required end up to be VERY expensive, about 10 time the budget of what you get with conventional fluo or tungsten.
what i found great for led is the cheap UFO type (usually less than $10) and the 108 led torch.
http://www.ebay.com/itm/UFO-Lantern...502?pt=LH_DefaultDomain_0&hash=item1c1e915dce
http://www.ebay.com/itm/Guide-Gear-...489?pt=LH_DefaultDomain_0&hash=item20bc02a949

you can get hours of light from 2-3 AA batery cell, and are great to shed light very locally. For the ufo, you just leave them on the floor, behind a chair, a plant, curtain (no heat, so no risk) , you can hook or stick them virtually every where in seconds . The torch can be fixed on a tripod (or a mic stand) to give a third point of light, easy and fast. Always got 3 or 4 of them in my bag.
 
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well since led are working with low voltage (supplied by usually by a AC/DC converter), i do not see the point to convert 12V to 110 then 110 back to 12 or 24.
each time you add trouble and loss.
let's say invertors are a pain, so let's use them only when there is no other choice.
 
nosys70 said:
well since led are working with low voltage (supplied by usually by a AC/DC converter), i do not see the point to convert 12V to 110 then 110 back to 12 or 24.
each time you add trouble and loss.
let's say invertors are a pain, so let's use them only when there is no other choice.
Click to expand...

Not all. I have several that are 110V only. Possibly internally there is a transformer but I am not sure.
 
usual led element is 3.5V, but it is common to have them mounted in serie to have more usual voltage, between 12 and 48, 48 being an industry limit between considered low and
high voltage, thus low voltage apparatus requiring less paper work for passing country regulations
But i have chinese led bulb using a bunch of leds all in serie to reach the common 220V. Unfortunately this proved to be a bad solution since the bulbs burned after only few hours.
all tactics to mount leds (parallel and serial) have their own advantage and weakness.
 
High wattage tungsten to light a car interior in this day and age? I'd pass.

Stuff I own that I might utilize: Litepanels MiniPlus heads, Kino Flo 12" tubes, GAM Stik-up heads; 12v 34 Ah sealed lead acid battery mounted in Pelican case with two 4-pin XLR connections; Exeltech 250w pure sine wave inverter w/4-pin XLR input.

Btw, a high quality inverter capable of delivering 1000w would be very, very expensive. And powering it off a car's alternator/battery would be a gamble, I suspect.
 
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@ maplecap, where can I find these ? (12v 34 Ah sealed lead acid battery mounted in Pelican case with two 4-pin XLR connections)

Thanks, J.
 
I have a Cool Lights LED600 that is 12v powered via a 4pin XLR. There is a external transformer to run this from 120VAC. I can't imagine that the power is further reduced to the typical LED voltage, so they are probably run in groups in series to make 12VDC possible on this device. By the way, this light will run for a long time indeed on a typical automotive battery.

Grant
 
julian said:
@ maplecap, where can I find these ? (12v 34 Ah sealed lead acid battery mounted in Pelican case with two 4-pin XLR connections)

Thanks, J.
Click to expand...

I'm sure you can source some variation of one from any number of production supply houses, or build your own. It's basically a block battery. Mine came from Location Sound Corporation in Los Angeles. They're pretty common on sound carts. LSC has them custom assembled by a third party in LA. I think they sell them for around $300, though it might be costly to ship. I have a little charger for it, too, which also came from them.
 
David W. Jones said:
Typical Honda generator rentals useually start around $50 a day depending on your needs.
Click to expand...

I considered suggesting that (I own a Honda EU2000i), but I think it would be overkill for an interior night setup. If it were a daylight thing, where you needed to power an HMI or two, it would be sensible (if professionally rigged and being driven on a closed course).
 
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