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Solar project - consumption calculations.

Hi All,

I need to create a solar powered Wireless Access Point and IP camera - but I'm having problems calculating the consumption vs. battery size vs. panel size - can anyone steer me??

Here's the scenario: I'm a member of a not-for-profit sporting club, and we're being hindered by vandals at our club house and field (mostly at night). There's no power available as its slightly remote, however there is a location I can get a wireless IP link to - that's the easy bit.

I have some limited electronics know-how, however this one is a little different from what I'm used to!

Here's where I'm at so far:

- The AP consumes 2A at 5VDC

- The Ir capable IP Camera also consumes 2A at 5VDC

I had planned for:

- A runtime of around 20 hours (Am I asking too much?)

- Budgeted for a 38Ah 12V Yuasa battery

I'm stuck at:

- A circuit diagram for an efficient 12V->5V power supply capable of at least 5A

- What spec solar panel should I look at? What kind of cheap solar regulator?

- How to calculate the base run-time on the above figures?

The solar panel will be mounted on a flat roof, but I can rig up a support to hold it at an angle to provide it with the longest duration of direct sun.

Obviously as an NFP budget is not our friend, so I'm happy to build\beg\borrow wherever I need to.

I'd *really* appreciate anyones time in pointing me towards the correct values and formulae.

Many thanks, Tim

Reply to
Timmah
Loading thread data ...

Do you know about Ohms Law ? google it of you don't .

Reply to
atec 77
** Desperate Groper Alert !!!!!!!

** Pilot needed - Novice Google Groper headed for deep waters ......
** No camera is much good in the dark.

Everything just looks kinda blackish ......

** What is your club being troubled by pal - marauding wombats maybe ???

Lemme tell ya a simple fact - the cops are not one bit interested in nabbing any (4 legged) wombats.

Blurry IR pics of *god knows who * will interest them no better.

Kindly re-think your mad assumptions - remote security video surveillance

  • in the BLOODY dark * is a total waste of time and money.

However, I'm sadly very sure there are numerous ABSOLUTE e WANKERS lurking here who are only too happy to help you waste lots of both the above.

Yawn .. ......

...... Phil

Reply to
Phil Allison

Thanks Atec -that brought some memories back & has answered my questions (I think :-) )

Cheers, Tim.

Reply to
Timmah

Hi Phil,

Thanks for the motivational speech. It sounds like you know our situation better than we do!

I guess this list has its own magic way of 'outing' "ABSOLUTE e WANKERS" as you so thoughtfully put it.

Best, Tim.

Phil Allis>

Reply to
Timmah

Movement activated lighting and camera grab ?

So with these images of kids in tracksuits and hoods, what are you going to do with them ?

Get a dog - a big hungry one

Reply to
Andrew Rich

Wanker ? that would be :Phil Allison and practicing poofter .

Reply to
atec 77

we

prepared

I have to ask , will the camera run at night ? if not then your figures are double the requirement

Reply to
atec 77

Hi atec,

For some of the night at least - yes. I imagine I could switch it off at around 0300hrs and back on at around 0700hrs. I ran the numbers for

24 hours to give me some 'buffer' space.

The camera has a small set of Ir setup for motion detection, and I was intending to use the motion detect alarm dry contact to fire up the other Ir spots - so I can save some power there. I'll use an LDR and build a 'daylight' interlock for these as well - no point wasting juice during daylight hours.

Cheers, Tim.

atec 77 wrote:

to

need

times we

prepared

Reply to
Timmah

Thanks Rebel,

That's fantastic! There are so many LMXXXX based regulators around, but I can't see these being any good for solar applications.. The SMPS sounds like the way I need to go. I'll try and find one pre-fab.

I have a fairly good spot to mount the panels, they'll be pretty much out of view & should be safe(er). Maybe one of the guys can build a rio style mesh cage for it without distrupting too many rays.

I also have the option of giving the batteries a boost once a week with a portable generator - I could probably get between 4 to 8 hours of charge in once a week if needed.

Thanks again, Tim.

rebel wrote:

we

prepared

Reply to
Timmah

Start with some reasonable assumptions:

Load: unless you plan on turning it on/off with a timeswitch, your AP needs to run 24/7 even though the camera MAY be controllable.

Battery draw: a SMPS doing the 12V->5V at say 80% efficiency (may be higher, but don't bank on it) so 20W @ 5V =~2A @ 12V/14V

Battery sizing: "normal" commercial design practice is for 10-11 days of no sun. Your gear will pull 2A*24*10days =480Ah.

Solar panel sizing: we used to work on a MINIMUM of 1A per 10Ah of battery. Depending on your location (latitude/cloud etc) you may vary that, but you need to be concerned with charge recovery after several days of no sun. Trust me,

48A of panels is a shitload of area AND $$.

Those calcs are based on the way we set up solar comms sites. The only times we had no power was from faults (battery bank issues or stolen panels). You can shorten up on the battery endurance (and the panel capacity) IF you are prepared to take some risk, which we couldn't do - govco comms needs to keep sizzling.

That's my slant on it. Others may well differ.

Reply to
rebel

"Timmah"

** Fuck the HELL OFF !!

Top posting Bloody IDIOT !!

...... Phil

Reply to
Phil Allison

"Timmah"

** What is your club being troubled by pal - marauding wombats maybe ???

Lemme tell ya a simple fact - the cops are not one bit interested in nabbing any (4 legged) wombats.

Blurry IR pics of *god knows who * will interest them no better.

Kindly re-think your mad assumptions - remote security video surveillance

  • in the BLOODY dark * is a total waste of time and money.

However, I'm sadly very sure there are numerous ABSOLUTE e WANKERS lurking here who are only too happy to help you waste lots of both the above.

Yawn .. ......

...... Phil

Reply to
Phil Allison

"Timmah"

** What is your club being troubled by pal - marauding wombats maybe ???

Lemme tell ya a simple fact - the cops are not one bit interested in nabbing any (4 legged) wombats.

Blurry IR pics of *god knows who * will interest them no better.

Kindly re-think your mad assumptions - remote security video surveillance

  • in the BLOODY dark * is a total waste of time and money.

However, I'm sadly very sure there are numerous ABSOLUTE e WANKERS lurking here who are only too happy to help you waste lots of both the above.

Yawn .. ......

...... Phil

Reply to
Phil Allison

"Timmah"

** What is your club being troubled by pal - marauding wombats maybe ???

Lemme tell ya a simple fact - the cops are not one bit interested in nabbing any (4 legged) wombats.

Blurry IR pics of *god knows who * will interest them no better.

Kindly re-think your mad assumptions - remote security video surveillance

  • in the BLOODY dark * is a total waste of time and money.

However, I'm sadly very sure there are numerous ABSOLUTE e WANKERS lurking here who are only too happy to help you waste lots of both the above.

Yawn .. ......

...... Phil

Reply to
Phil Allison

"Timmah"

Reply to
Phil Allison

"Timmah"

** What is your club being troubled by pal - marauding wombats maybe ???

Lemme tell ya a simple fact - the cops are not one bit interested in nabbing any (4 legged) wombats.

Blurry IR pics of *god knows who * will interest them no better.

Kindly re-think your mad assumptions - remote security video surveillance

  • in the BLOODY dark * is a total waste of time and money.

However, I'm sadly very sure there are numerous ABSOLUTE e WANKERS lurking here who are only too happy to help you waste lots of both the above.

Yawn .. ......

...... Phil

Reply to
Phil Allison

Hello again Phil,

I'm Narcissistic? Read my first post (or learn the real definition of narcissistic), I'm doing this for a small community of people with a common interest. What's narcissistic about that?

I'm not going to "Fuck the HELL OFF" at your command, but you are most welcome not to visit this topic in future if you prefer. No obligation on your behalf either way and of no consequence to the rest of us.

Cheers, Tim.

Phil Allis> "Timmah"

Reply to
Timmah

I would suggest you speak to a solar company as I seem to remember reading about a controller which might just offer the voltage control you look for , and low wastage . Good luck with it and I would be interested in the results.

Reply to
atec 77

Phil Allison wrote: Off your meds again sucky boy ?

Reply to
atec 77

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