# Solar project - consumption calculations.

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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

- 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

Re: Solar project - consumption calculations.

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

Re: Solar project - consumption calculations.

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

Cheers,
Tim.

Re: Solar project - consumption calculations.

** 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.

* 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

Re: Solar project - consumption calculations.

**  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.

* 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

Re: Solar project - consumption calculations.

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 Allison wrote:

Re: Solar project - consumption calculations.

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

Re: Solar project - consumption calculations.

"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.

* 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

Re: Solar project - consumption calculations.

Gee Phil, you are really slowon the pick up today.
This is a "sporting club" Phil, which is code for GUN club. The cameras
are to warn them when someone is on site, a siren sounds and the vandals
are given a sporting chance to flee {:-) before they become targets.

OTOH, everything you say is correct. Think of it more as an intelligence
gathering exercise, to work out when the vandals tend to visit. They
might get lucky and get a readable number plat or something.

Phil, have you ever looked through any video or surveillance camera in
the night time? Most respond well to IR.

Actually Timmah (can not help by think of Timmy from South Park) might
be better just to run a simple set of flood lights driven by motion sensors.

Re: Solar project - consumption calculations.

I think it'd be "Timmah!" if that were the case.

sensors.

Or maybe just a battery, a PIR movement sensor, a solenoid and a shotgun.

Re: Solar project - consumption calculations.

"Poxy"

** Merely setting up such a " man trap" is a VERY SERIOUS criminal offence.

Could get you 5 years in the clink.

http://www.austlii.edu.au/au/legis/nsw/consol_act/ca190082/s49.html

Plus various firearms offences on top.

If it shot anyone, the owners would be charged with  murder or malicious
wounding etc.

Gets you 14 to 25 years in the clink.

.......   Phil

Re: Solar project - consumption calculations.

Who said the shotgun was aimed at anyone.

Re: Solar project - consumption calculations.

"Terryc

**  YOU have no idea.

** Absolute  BOLLOCKS.

**  The  " vandals"  will simply steal or destroy any camera gear.

**   Yawn....

You are just as clueless as this Timmah fool.

.......   Phil

Re: Solar project - consumption calculations.

Shit Phil, you are really, really thick. Now you've told the blighters
they will take measure to protect it and make it harder to "re-locate".

Re: Solar project - consumption calculations.

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

Re: Solar project - consumption calculations.

"Andrew Rich"

** Best idea I've seen posted so far.

But someone has to feed and check on the dog daily and there has to be a
perimeter fence to keep him in.

.......   Phil

Re: Solar project - consumption calculations.

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 48%0Ah.

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.

Re: Solar project - consumption calculations.

we

prepared

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

Re: Solar project - consumption calculations.

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

Fuckwit On NG NOW !

"Timmah"

**  Fuck the HELL  OFF     !!

Top  posting   Bloody  IDIOT    !!

......  Phil