I just ordered 3 Linksys WVC 200 PTZ cameras and 3 IR illuminators. I want to place them outside in a sealed box around my yard in a non powered area and I am looking to attach SLA batteries and solar charging to run them The power supply for the camera is a "5DVC 2.5A Power Supply" and the illuminator runs a "DC12V 1.5A Power Supply" I want to buy (1) "12V 12A" SLA Batteries for each camera and illuminator set with a solar panel charger but I have just a few questions.
> First - Does "5DVC" the same as "DC5V"?
Yes, it does.
> Second - Will the battery that I want to buy be sufficient to power those two apparatus on that one battery?
That depends on how long you plan to run the wireless cameras. The way I like to calculate these things is to convert everything into watts and watt-hours.
Let's start off by assuming you want to run the camera 24 hours/day. Let's also assume that the whole time those power supplies will be running at full power. Here's how we calculate the watts each part takes:
Power = Current x Voltage
Wireless Camera:
---------------
Power (watts) = 2.5A x 5V DC = 12.5 Watts
IR Illuminator:
--------------
Power = 12V x 1.5A = 18 Watts
Now we need to figure out how much energy (watt-hours) these devices will consume over the period of a day. We simply multiply the watts for each times the hours they'll be running per day (all day long in this case):
Energy (watt-hours) = (Watts for Camera x 24 hrs) + (Watts for IR Illuminator x 24 hrs)
= (12.5W x 24hrs) + (18W x 24hrs)
= (300 W-hrs + 432 W-hrs)
= 732 W-hrs
Now, because all of the electronics, the batteries, wires, etc are not 100% electrically efficient we need to increase this number by 30%:
Daily Watt-Hours =
= 732 W-hrs x 1.3
= 952 W-hrs
30% might be a little on the high side but you will need a DC-DC converter to bring the battery's 12V voltage down to the 5V for the camera (or if those power supplies run off of 120V AC then you will need a minimal inverter of 50 to 100W, 12V). The 12V illuminator I would think you could run directly off of the battery (though the battery isn't exactly 12V).
Ok, so now for the moment of truth - let's figure out how many amp-hours your battery needs to be. We'll convert the watt-hours value to amp-hours:
Amp-Hours = Watt-hours/Voltage
= 952 W-hrs/12 V
= 79 A-Hrs
That's not quite the end of the picture. You don't want the battery to 100% discharged by the end of the day or your battery will be lucky if it lasts you more than a few days. You need to make sure that the battery doesn't discharge more than 50% to ensure a relatively long lifetime. In other words, we need to double that number:
Amp-Hours of Battery = 79 A-Hrs x 2
= 158 A-Hrs
So the bad news is the battery you selected is significantly less than you would need. You need one that's around 160 A-Hrs and 12V (or a combination of batteries that gives you the same).
Also, if you're in a location that dips down into chilly temperatures the battery's capacity will be reduced. For instance, at 32 degrees F, a lead-acid battery will have about 60% of its capacity at 77 degrees F. So, if this your case you'll need to use an even larger battery to have enough capacity.
Finally, we did these calculations assuming you'd have enough sun ever day and no rainy/overcast days. In reality you want to make the battery even larger to take into account a few continuously overcast days. For each additional over cast day, add another 158A-Hrs to the battery size (at this point you'll need to have multiple batteries).
>Third - Will the battery last for at least 12 hours while running those devices and if not, what kind of battery should I buy?
If you run it for 12 hours only, you'll need half the size of the battery we just came up with above (i.e. about 80 Amp-hrs, 12V).
> Fourth - What wattage do I need for the solar panel and what kind of solar charge controller should I purchase to adequately charge the battery during the day.
Assuming you'll want to use this all year round, we'll need to size the solar panel to provide enough power when you get the least amount of sun (usually in the winter). Since, I don't know your location, let's just go with Columbus, Ohio as an example. Here's the formula that we need to go through:
Power of Solar Panel = (Daily Watt-Hours)/Lowest Insolation Value for Location
I look up the lowest solar insolation value for Columbus, OH here:
http://howto.altenergystore.com/Reference-Materials/Solar-Insolation-Data-USA-Cities/a35/and I see that it is 2.66 hrs. So our calculation is:
Power Solar Panel = (952 W-hrs)/2.66 hrs
= 357 Watts
So you might consider 3 x 120 or 130 watt solar panels (e.g. Evergreen EC-120, Kyocera KC-130, etc) connected in parallel (positives of each panel all connected together and negatives all connected together).
Solar Charge Controller:
-----------------------
I'd recommend a solar charge controller that has "LVD" (Low Voltage Disconnect). This feature allows you to connect up your loads (the camera and illuminator) up the charge controller, then the controller will automatically disconnect the loads from the battery if it ever gets seriously low (to protect your battery's life).
To size the charge controller we just need to get one that can handle all of the current from those three panels. Roughly speaking here's how we can calculate it:
Current = Total Power of Solar Panels/Voltage of Panels
= 360 Watts/12 Volts
= 30 Amps
So we need a charge controller that can handle 30 Amps but probably better to choose 35A-40A as a safety margin (and in case you go with 130 Watt panels instead of 120). Here are some examples:
Phocos 40A 12/24V Controller
Click:
http://store.altenergystore.com/Charge-Controllers/Solar-Charge-Controllers/Pwm-Type-Solar-Charge-Contollers/Phocos-Solar-Charge-Controllers-Pwm/CX40-40A1224V-PWM-Charge-Controller/p1018/Morningstar Tristar 45A 12/24/48V Controller
Click:
http://store.altenergystore.com/Charge-Controllers/Solar-Charge-Controllers/Pwm-Type-Solar-Charge-Contollers/Morningstar-Charge-Controllers-Pwm/TRISTAR-45-45A-CHG-CTLR-WITHOUT-DISPLAY/p806/Xantrex 40A 12/24/48V Controller
http://store.altenergystore.com/Charge-Controllers/Solar-Charge-Controllers/Pwm-Type-Solar-Charge-Contollers/Xantrex-Solar-Charge-Controllers-Pwm/Trace-C40-40A12-48V-CHARGE-CONTROLLER/p2070/> Finally - How do I "plug them in" to the whole battery power thing?
The panels you'll want to wire in parallel (positives to positives, negative to negatives). Then you'll want to run a pair of wires (positive and negative) to the charge controller. Then from there a pair of wires to the battery (or batteries). Then connect up your loads to the battery. If you want to use a DC-DC converter to convert the battery's 12V down to 5V for the camera, I'd recommend Solar Converters EQ12/24-5R5 which converts 12-24V TO 5V, and works with up to 5 amps.
Last but not least, you'll want to put DC rated fuses or breakers (over current protectoin) between each part of the system. For the fuse between the solar panels and the charge controller and the one between the controller and the batteries you should be able to get away with 40 to 50 Amp You'll want to put fuses between the battery and the camera and illuminator.
Hope that helps!
