Power Inverter Questions

t_elliott

t_elliott

Member
Hey Everyone,

Quick couple of questions. I'm looking to light the inside of a car while it's driving. I just went to home depot and bought a power inverter, it's this model - http://amzn.to/e80kk2 - Basically it's one of the ones that you hook to your battery. I originally bought it as a quieter alternative to a generator. Now, here's my question. I want to use a 300watt usage fluorescent light that I have to light a car interior during daytime. Would it be safe to use this inverter WHILE the car is being driven?

I don't know if this is general knowledge that I don't have for some reason. Something tells me that It might not be a good idea. Just wanted to be sure.

Thanks for your time guys.
 
My plan is to gaff everything down really tight, and run a small stinger from the inverter through the window into the car.
 
There have been a couple of threads on using inverters. In a recent one, a person posted that had fixed up a van to be lit while mobile via inverters. The thing with inverters is that you need probably about 2x the load wattage you expect as a spec for the inverter. The reason for this is due to start up considerations, where devices will suck a lot of current during startup, and will overload a source that is 'just enough' for their steady state current draw.

So, in your case, I'd look at 1000 W inverters. At that wattage, you do not want to use the 'cigarette' lighter connection, but clamp directly onto the battery terminals. If you are using the car's own battery, I'd start the car first... I'll leave the safety issues to you... suffice it to say, I'd probably worry about using the car battery and dressing the cables out and around...

The other issue, is given you mention daytime shooting, I don't know that a 300 W light will be sufficent to overcome sun light if your wanting to balance car interior to exteriors. In other threads on such a subject, the consensus seems to be
that it would not really benefit.

But you have to decide.
 
Thanks for your response.

Interesting. I think I have a little over double the load wattage for the light. The light I plan to use is light that uses about 300 watts, but puts out about 1k's worth of light. It's definitely enough light to make a difference as far as balancing. Oh the joys of fluorescent lights. I've already used the light through the inverter with my car idle.

I guess I just wanted to make sure that If the cables were all secure, that there would be no issues endangering the car, or the fixture if the car were being driven instead of idle. I don't know what happens within the battery when the car is actually moving.
 
T Elliot,

Clark is partially right on the startup issues, but for lights, you don't need much extra. For capacitor motors, the reserve is really needed for startup. What is more important is duty cycle. For example, a 1000w inverter might only be rated for 500w continuous, so read your specs. And as Clark suggested, if there is much current, wire direct to the battery. For flos, the type of inverter may matter. Cheap inverters are usually modified sine wave and may not be good for the ballasts in the flos. Tungstens don't care. Pure sine wave inverters are available, but are expensive.

Now a suggestion: This would be a perfect spot for something like a Cool Lights LED 600. It would run easy off your lighter plug, no inverter required. I fought the LED craze for a while, but after the Cool Lights purchase, I am a believer. Not right for everything, but when you can work it in, it is a no brainer. Note: A 1/2 minus green is recommended to adjust to 5200k and Cool Lights includes a nice set of full size acryllics with the unit.

Grant
 
t_elliott said:
Thanks for your response.

Interesting. I think I have a little over double the load wattage for the light. The light I plan to use is light that uses about 300 watts, but puts out about 1k's worth of light. It's definitely enough light to make a difference as far as balancing. Oh the joys of fluorescent lights. I've already used the light through the inverter with my car idle.

I guess I just wanted to make sure that If the cables were all secure, that there would be no issues endangering the car, or the fixture if the car were being driven instead of idle. I don't know what happens within the battery when the car is actually moving.
Click to expand...

I don't see a problem per se. You are going to add about 25 amps of load. That's about like a rear window defroster or the heater/AC fan on high. Don't run either of those and you should be fine.

Car batteries can be dangerous, they contain acid, can contain and release explosive gases, and can blow up from sparks though, so you should follow any instructions that came with the inverter and/or car or battery. Wear eye protection when hooking it up. I thought about telling you the procedure but decided it is smarter to suggest that you inform yourself and follow all relevant precautions and instructions.
 
Its seems better to be running the car while running the light, the car engine charges up the battery, so if it works idle it will work running

now all you have to do worry about is safe rigging dazzling the driver, etc

I would however, like everyone else, suggest an inverter rated at twice the wattage of the device - if it is a consumer grade inverter

S
 
Cool. Thanks guys.

Yeah, I realize this definitely isn't the best set-up. As soon as I can afford it I'll definitely go the LED route. Had the shoot today, everything went well. No explosions, or failures of any sort. I am concerned that the inverter I used is a modified sine wave. But luckily, I kept the receipts and stuff. I pulled off what I needed to, and everything looked great. But I definitely will be seeking better options for the future.

Thanks again guys.
 
I've done this... a lot.

You need a PureSine inverter to make sure the signal is clean or you'll have problems with things like HMI's and Fluo's because the converter doesn't play well.

Put it all in a crate, tie it down.

Keep a back-up battery, because the first one will go fast.

What you may want to do instead of all of that is find someone with a Kino Car Kit or a fluo light that you can plug into a cigarette lighter, the alternator will keep the battery going so don't use it while the car's off.

Good luck.
 
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