Marine (deep cycle) battery to power a 5v (1300ma) webcam

[gginnj]

This is actually a two part question.

1. How do I reduce the 12v marine battery down to 5v DC, the wireless
webcam draws 6.5watts @ 5v .

2. I'm charging the 12v battery with a 1.8watt @ 12v solar cell.
2nd question, how do I determine if the 1.8w @ 12v will supply
enough power for the device to draw 6.5w @ 5v? Is a watt a watt?
even though they are at different voltages?

Thanks
GG

 

[wp100]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

Hi,

1300ma at 5V seems a very high current for a web cam - is it fitted with uv lights etc ?
Think you need to check its actual current with a meter

You need a simple voltage regulator like a 7805 max 1amp or LM323 max 3amp.
Choose your regulator so the actual current from it is no more than 50 to 60% of the maximum to ensure good life.

Just search for the regulators datasheet and it shows the full circuit with just 2 extra capacitors.
You will need to fit them to a decent size metal heatsink to dissipate the heat generated, particulalry if it is 1300ma.

If your web cam does use 1.3A then your solar panel will have little effect.
The battery looses its own charge, the voltage regulator looses a lot of power in dropping the voltage from 12 to 5 v, then you have the actual load of the camera.

 

[gginnj]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

Thanks for the information.

The camera also includes a 802.11 wireless access transmitter, and I believe
it has some basic pan and tilt (I think). I havn't purchased it yet. so, maybe
1.3a might be correct.

Would running it off a 6v battery be any better, since the regulator wouldn't
be burning off so much energy. I guess the only problem now would be
getting the 12v charger to work with the 6v battery.

Is is possible to hook two 6v batteries in series for charging (making 12v),
but have them hooked in parallel for usage, so it would still be 6v ?

I could always get a few more solar chargers to bump up it's 1.8watts, or buy
a stronger one (5watt or 15 watt) but still 12v.

Thanks

 

[wp100]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

Hi,

Well 1300ma is a lot of power from batteries, I'm sure the web cam comes with a mains wall pack to power it ?

You do not say why you are not using that , yet you can charge the battery from the mains.

Perhaps if you can say what you are trying to do, power wise, then we can better advise you.

Again is there any reason why you cannot use a simpler wired camera which are usually a lot less current - I power 3 from one 5v 1A regulator.
Colour cameras give a much better daylight picture but a B/W unit is much better in low light.

 

[bepobalote]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

May I suggest to use a switching regulator?
The efficiency will be higher and you will not waste lots of energy in heat...

 

[gginnj]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

I wanted to put this in the furthest corner in the back yard. Yes, I could use power of ethernet and bury a cable......Or run a power outlet, which would be very costly.

Basically, it's a need (not really), vs want (would be cool to have) so the cost factor of hiring an electrician to run AC around the yard doesn't float. I don't like
the idea of running an ethernet cable all the way out there as well. I'm not sure
of the maximum distance when you include the power over ethernet into the cabling, but this would probably be borderline in distance.

And of course, I'd also have the problem of the camera would be running at night also (unless I put in some kind of dusk/dawn shutoff) and there would be no solar charging during that time.

I would be interested to see how long it takes for the camera to drain the battery down with, and without the solar panel, to see how much of difference it makes.

Seems a shame to have this little gadge, and not be able to do anything useful with it!

 

[wp100]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

Hi,

Right can see your situation clearer - but what kind of distance are we talking about to the very back of your yard from the house.

The only problem with using a camera and batteries that far away is that someone will knick them before you see it on the camera !

I would be tempeted to mount 2 cameras on opposite corners of the house so you get better close up coverage.
Install them openly if you want them to be a deterrant, or hide them in the woodwork around the edge of the roof to find out what is really going on if you suspect some improper entry to your property.

If you use software that does motion detect you can get an alert when even a small cat or dog walks by. You can also more easily cover the area near the house with PIR floodlights.

 

[gginnj]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

I'm not too worried about anyone stealing anything. it would need to be encased anyway, for weatherization, so stealing it would more difficult than it would be worth (effort that is).

anyway...thanks for the info, at least I have something more to look into. Something to try in the spring, once the snow is gone.

 

[wp100]

Re: Marine (deep cycle) battery to power a 5v (1300ma) webca

Hi,

Well if you do give it a try you will need a 12v battery as the 5v, 2 or 3amp regulator needs at least 7.5v input to produce the 5v.
http://www.datasheetcatalog.org/datasheet/stmicroelectronics/2165.pdf

Your camera module rated at 1300ma - I would assume that is a mamimum current rather than continuous - so assuming your battery is rated at around 100va then you should probably get a couple days at best before recharging, but you will really need to do some actual trials see see how long you really get because there are no exact figures to work on.

If that works out ok, then it might be worth looking at a switching power supply to reduce the power wasted by the standard regulator, as suggested by bepobalote

Think you will then have to do your electrical and financial sums as to how worthwhile solar panels would be - it might be simpler to use 2 batteries, one in use, one being charged.