Carlitos 0 Posted April 26, 2010 I am trying to use a CCTV camera under water with proper protection. The camera spec is for 12V and it has IR for night vision or low light environments. 12 Volts is not a easy battery to find and they are expensive. I removed the IR part of the camera, used an 8 Volts power supply, and seem to be working well but I have tested it for just few minutes. My idea is to use a pair of 9 Volts batteries in parallel to get enough amps for the camera so it does not run out of power too quick (I do not know how long it will last so far) My question is, Can I use a 9 Volts battery safely or will it damage the camera? I know that more voltage could fry the camera but I am not sure if low voltage does the same or so. Since I already tried the camera with 8 Volts for few time (less than a minute) I suspect that the requirement of 12 Volts is divided between the IR needs and the camera needs. Having disconnected the Ir section, will it be safe using just 9 Volts? I hope I am not making an stupid question and I appreciate any help on that regard. Thank you, Carlitos. Share this post Link to post Share on other sites
Soundy 1 Posted April 26, 2010 Under-voltage shouldn't harm the camera, but it probably won't run at peak performance, either. I got called in to check an enterphone camera a while back, because it had really poor, washed-out picture... turned out the only problem was that it was only getting 10V. Boosted it up to a full 12.5, and the picture was spectacular by comparison. Your main problem will be, 9V batteries tend to be very low capacity (assuming you're talking the standard consumer type with the two snap-on terminals on the top). The datasheet for a standard Energizer alkaline cell, for example, shows that at 500mA draw (which is about what your camera will want with the IR on), the battery's capacity is under 400mA hour when running down to 4.8V. Since the camera will kack out long before that point, you're probably looking at well UNDER half an hour on a single battery. Paralleling two of them might get you up to 45 minutes. If space isn't a concern, you'd probably be better off with a pair of 6V lantern batteries in series... or a pack of D cells... or ideally a sealed lead-acid "gel cell" battery like the type used in UPS battery backups and alarm panels - more capacity in a smaller space, and rechargeable as well. Share this post Link to post Share on other sites
survtech 0 Posted April 26, 2010 9 volt batteries will probably not last very long and it is not recommended to run two in parallel without isolating them via diodes; which will cut the voltage to approximately 8.3 volts to the camera. The typical 12VDC CCTV camera without IR requires approximately 3-4 watts; which is .25A to .33A at 12VDC. The typical 9V alkaline battery will last far less than 1 hour at that draw. Not only that but if you look at a graph of battery life vs. current draw you will see that the voltage will drop of pretty quickly. Since you are already starting with 25% less voltage than the camera requires, you will probably find that the voltage will drop to the point where the camera becomes unusable very quickly. Here is a link for a data sheet on Energizer 522 alkaline 9V batteries: http://data.energizer.com/PDFs/522.pdf I suggest using an 8-pack of 1.5 volt batteries; either AA or AAA. They will last far longer and you could use rechargeables. Share this post Link to post Share on other sites
survtech 0 Posted April 26, 2010 Soundy: Shakespeare! Share this post Link to post Share on other sites
Carlitos 0 Posted April 26, 2010 Soundy and Survtech: Thank you very much for your quick response. I think it will work well for what I am planning. The camera I am going to use to video my son swimming and the signal recorded into my video recording camera from Apitek that can record from external source. I just need it for short time to see how his technique under the water and his turns are. The power or batteries are going to be out of the water with me. A power/video cable will provide the power to the camera and the video signal back to my recording camera. I will be able to change the batteries as needed. I will use an aluminum bar to attach the CCTV camera an keeping it submerged. I will add a on/off switch to power it as needed. It is a project that I hope will stay under $100-$150 instead of $1,500 for some "professional" ones that the small club cannot pay for. Regarding the battery arrangement, you gave me new ideas that I will review and probably test based on the initial try results. I guess all the little boys and girls will be happy with the new toy and the posibility of improving their times. Again, thank you for your response and support. Carlitos. Share this post Link to post Share on other sites
tomcctv 190 Posted April 26, 2010 you might want to check on your state law on recording children. before you build and use anything. this is a very bad idea for cctv use. Share this post Link to post Share on other sites
Soundy 1 Posted April 26, 2010 If you're running power and video via a wire to the camera anyway, why not just use the supplied wall-wart? As long as it's a transformer type (not switching) there's electrical isolation and it should meet even the most stringent electrical codes. As far as laws about recording children, this isn't being used for covert surveillance; it's being used in the same capacity as a standard camcorder, the kind every parent brings to their kids' birthday parties. I don't foresee there being any problem there. Share this post Link to post Share on other sites
tomcctv 190 Posted April 26, 2010 If you're running power and video via a wire to the camera anyway, why not just use the supplied wall-wart? As long as it's a transformer type (not switching) there's electrical isolation and it should meet even the most stringent electrical codes. As far as laws about recording children, this isn't being used for covert surveillance; it's being used in the same capacity as a standard camcorder, the kind every parent brings to their kids' birthday parties. I don't foresee there being any problem there. soundy bad info. you can record your own kids but not anyone elses. and keep the footage. so yes this does need to be checked with the state law. Share this post Link to post Share on other sites
Soundy 1 Posted April 26, 2010 soundy bad info. you can record your own kids but not anyone elses. The camera I am going to use to video my son swimming and the signal recorded into my video recording camera from Apitek that can record from external source. And for that matter, if you bring a camcorder to your kid's birthday party, how are you supposed to ONLY record your kid without getting anyone else's? Fine, OP, cover your ass, get each parent's written permission if you plan to record anyone else's kids... but again, despite this being a CCTV-type camera, this is not a typical CCTV implementation. Put your camcorder in a plastic bag and drop it underwater; this is effectively all you're doing. Nobody ever worries about pulling out the camcorder, video-capable camera, or cel phone at a kids' party and letting it roll. Share this post Link to post Share on other sites
Carlitos 0 Posted April 26, 2010 Thanks for the warning, but I am aware of recording other kids around. I will record my own son and any other that the parent is present and would like to see his/her stroke or technique. We will review it right there in a regular old TV. The idea is to show the swimmer what are they doing correctly and what do they need to correct. I am sure if my son improves, ALL OF THEM are going to ask me for some video review. Again, thank you very much for be aware of potential legal issues with my experiment, I appreciate your input in that regard. I know that there are some cameras to use under water but I am not planning to get in the pool and hold my breath and record it, so an "extension camera" would do the job. Remember that my recording camera (no the CCTV) is capable of recording from an input port, so the CCTV camera would work as an extension that can be submerged to analyze his technique. I am not going to be able to zoom in or out so I already set it to a clear view at about 6 feet from the object. Too close is not that good, I need to see his entire body for the analyses. Some swimming schools do that but the equipments are very expensive and our small team does not have that money available. I will do that few times to make some corrections with the help of the coaches and again some time later to see if he has made the corrections. Thank you, Carlitos Share this post Link to post Share on other sites