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Remote power

PostPosted: Mon Feb 04, 2013 10:38 am
by macrae11
So I'm trying to plan a pretty wild shoot that's going to take place up a big hill away from power. The trouble is it's going to require a remote jib, or robocam. Essentially a servo driven pan and tilt head on the end of a crane. Pretty much everything we have runs on batteries, but not this head. It operates on 14.4VDC and draws about 1.5A. That's what the power supply is rated for so I'm assuming that's it's max draw and it would actually use less than that most of the time. So what are my remote battery options for this thing? I've thought about using a simple computer UPS but the one I have without testing, just doing a bit of math would only last about 15-20 minutes which isn't enough even if I brought 2 or 3. Ideally I'd need about 2 hours of run time. A generator isn't really an option unless it's super small because we've got to carry all the gear up the mountain plus I'd rather not have to deal with the noise. We might have snowmobiles for some transport but still weight is going to be a factor.

Any ideas?

Re: Remote power

PostPosted: Mon Feb 04, 2013 11:24 am
by Mathieu Benoit
U.S. Patent 1,119,732

Alain would be glad to build one for you. It should be possible for 1.5A depending on the amount of distance you are talking about.















dielaugh

Re: Remote power

PostPosted: Mon Feb 04, 2013 11:53 am
by macrae11
As much fun as going wireless would be..... I think a simple existing commercial solution might be preferred.

Re: Remote power

PostPosted: Mon Feb 04, 2013 12:04 pm
by Mathieu Benoit
macrae11 wrote:As much fun as going wireless would be..... I think a simple existing commercial solution might be preferred.


I just can't think of what that solution might be, at the moment. It would depend of not just the power you are drawing but how long you need to draw it for, to comfortably accomplish your shoot.

Re: Remote power

PostPosted: Mon Feb 04, 2013 12:47 pm
by macrae11
I know. Like I said I think 2 hours should give us lots of time, with probably only an hours of sustained operation in there. Maybe I'll call the mountain and see if they have a power drop somewhere in the vicinity and just bring some really long extension cables.

Re: Remote power

PostPosted: Mon Feb 04, 2013 2:09 pm
by Mathieu Benoit
Is 32lbs. out of the question for weight? Because this little guy could come in handy for ~ $250.00.

http://www.duracellpower.com/documents/tech-specs/DRPP600_SpecSheet_20121023.pdf

Re: Remote power

PostPosted: Mon Feb 04, 2013 3:12 pm
by macrae11
30lbs isn't over the top at all. And actually I have one of those in my garage already. I don't think it's as big as that one, but it might provide enough juice. Good thinking.

Re: Remote power

PostPosted: Mon Feb 04, 2013 3:16 pm
by Mathieu Benoit
macrae11 wrote:30lbs isn't over the top at all. And actually I have one of those in my garage already. I don't think it's as big as that one, but it might provide enough juice. Good thinking.


Do a dry run of it in-house and see how long it lasts at full power. That way you can gauge it's effectiveness in the field.

Re: Remote power

PostPosted: Mon Feb 04, 2013 3:38 pm
by macrae11
Yeah I will try that. I'm not currently in possession of the robohead at the moment though.

Re: Remote power

PostPosted: Mon Feb 04, 2013 4:10 pm
by Mathieu Benoit
macrae11 wrote:Yeah I will try that. I'm not currently in possession of the robohead at the moment though.


Find a replacement that draws the maximum wattage the robohead would at full tilt and see how long your battery lasts.

Re: Remote power

PostPosted: Mon Feb 04, 2013 4:43 pm
by macrae11
I'll test it with the actual head. I have access to it, it's just on long term loan at the moment. I'd be more confident with that than trying to find a suitable replacement.

Re: Remote power

PostPosted: Mon Feb 04, 2013 7:22 pm
by Alain Benoit
26Ah is the key here, assuming that rating at the nominal 115VAC that is a shit ton of power for the size, nearly 3 kWhrs.
Ignoring all of the inefficiencies of the system between the AC supply and the head, the math says you'd be able to run it over 100 hours.

A.

Re: Remote power

PostPosted: Tue Feb 05, 2013 6:20 pm
by macrae11
Well that sounds positive. How much effect will cold have on a battery system like this? we'll likely be operating in subzero temperatures.

Re: Remote power

PostPosted: Wed Feb 06, 2013 1:59 pm
by Alain Benoit
Depends on the chemistry, NiCd or Pb Acid you'd be done for.
I assume it will be some sort of LiPO with that kind of power density so maybe you can look it up.

A.