Independent CCTV systems

What considerations to take when designing
an independent CCTV systems?

cctv-installation-independent-camera-systemThere are a number of reasons why you might want to design an independent CCTV system. Some locations are too remote or complicated to run a power supply to, or you may want a temporary system which can be moved or removed at a later date.

Ready-made units for small systems

If your requirement is for a very small, simple system, then it is possible to purchase a ready made unit with everything you need built in. These typically have batteries which will last for 4 – 12 weeks depending on how much the camera is used and can be specified with infra red, motion detection and a range of other features. The downsides of these ready made cameras are that the images are generally not of a great quality, and the camera will only record to SD card so cannot be remotely monitored in most cases.

What are the requirements for pro systems?

For professional monitoring needs it can be better to design your own system using your choice of camera, DVR and other hardware to achieve the results you are looking for. To achieve this you will need to use one or more batteries, depending on the power requirements of your system and will need to make plans for the maintenance of the system and recharging of the battery units.

Check the power requirements

If you know what components you will be using for your system, check their power requirements and use this to calculate the battery power you will need. Batteries will have a rating in Ampere hours which will tell you how long they will be able to power the system. As an example, if the camera requires 250mA at 12v and your 12v battery is rated 7Ah, the system will work for around 28 hours (7/0.25 = 28). If the total requirement is 500mA then the same battery will operate the system for 14 hours. Consider how often you will recharge the system or change the battery pack. This will tell you how many batteries you need to operate the system.

Which battery to choose?

Deep cycle car and marine batteries last a lot longer than uninterrupted power supply (UPS) batteries. Good marine batteries can have a rating of as much as 100Ah so unless your system is small and has a very low total draw, these will probably be your best choice. Consider how you will charge the battery system.

It is important never to let the batteries discharge completely because, apart from interrupting your surveillance of the area, this can also damage the battery and prevent it from charging properly in the future. Installing a control unit between the system components and the battery will prevent this from happening. If you are using deep cycle car or marine batteries, taking them off site to charge and replacing them with charged units is likely to be impractical as they are extremely large and heavy. A better solution would be to take a generator onto site and charge them in situ.

Solar panels and wind generators – how could they be integrated?

If you have the space and the budget, connecting a renewable energy system to charge the batteries is a great option. Photovoltaic solar panels will generate electricity in any daylight, even on cloudy days, so you have the potential to integrate a large enough solar panel to provide all your energy needs if you have the budget to do so.

Wind is a little more unpredictable, as by its nature it is a weather dependent technology. You could use wind or a smaller solar panel to provide a trickle charge to the system, but then schedule in a visit say once a week or so to give the batteries a full boost.

Other considerations include factoring in the cost and power load of heaters for frost prevention if the system is to be operational in cold or exposed locations.  To conserve power requirements some cameras have inbuilt transmission which can work up to a mile away as long as there is line of sight. This means you can have the DVR at the receiver end, leaving only the camera to be battery powered.