What motion detecting wireless cam with long life battery?

[gadgetbest 0]

I need a a camera that can be set up in a place where people who is not supposed to be there gets there while one is out. Using AC as a power source would be a big hassle, so it's essential that this camera can be maintained by batteries and that these last for a long time (weeks). To solve the battery problem a solution is that the camera only shoots when it detects some movement. The concept would be the same as the one used in Bird Watching Cameras, with a slight difference: it would be best if this camera could send the pictures taken wirelessly to another device, placed in a nearby place and powered by AC current (here the AC power source would not be a problem). This way, the one trespassing the place where the motion detecting cam would be placed could not avoid identification by destroying the cam, because it would have already sent the snapshots taken to the "control center" wirelessly.

 

So, it needs to have these features:

 

1) Activated by motion

2) Long battery life

3) Wireless transmission to another device

 

However, it doesn't matter to me a lot that it can record video. If it only takes snapshots it would be enough.

 

Thanks in advance.

[Soundy 1]

Hmm, a few things to consider:

 

One, wireless transmission takes a lot more power than simply storing the image locally... thus, you may want to consider a camera that just records to an internal flash card. There are lots of them out there, from "covert" designs to megapixel cams.

 

Second, if you're recording to internal memory, I don't think you'll see substantial POWER savings choosing constant vs. motion-activated recording: the camera must still be active and capturing images; the only difference is with motion recording, it won't store the images unless there's movement. The alternative would be to have some other sort of motion-sensing device (PIR, etc.) that triggers the camera, but that too will drain power.

 

Third, if the camera runs on DC power, you can probably use a gel-cel (sealed lead-acid) battery to get significant runtimes out of it. Maybe pick up a couple of 5-7Ah batteries and swap them on a regular (weekly? bi-weekly?) basis - run on one, charge the other in another location. If you're recording to a flash card, you might want to check and/or change that out regularly as well, so there's the opportunity to do both at once.

 

Also, you shouldn't need to get 120VAC (or 240, depending on where you live) all the way to the camera... you just need a small wire to carry the 12VDC or 24VAC to it, and the power supply can go in another location.

[gadgetbest 0]

Thanks a lot for your reply, you have explained things very clearly. The solution I am seeking seems to be pretty hard to find from what you say...

 

Hmm, a few things to consider:

 

One, wireless transmission takes a lot more power than simply storing the image locally... thus, you may want to consider a camera that just records to an internal flash card. There are lots of them out there, from "covert" designs to megapixel cams.

 

And those ones like the "bird watching cameras" don't seem to need an acid battery in order to remain powered; from what the specifications say, one can get by with AA batteries for several months. I don't know what motion detecting mechanism they use in order to make the batteries last that much. You can see their specs if you look in google, I am not allowed to paste URLs here because I have just registered and my post count is too low.

 

The problem storing to memory is that the camera would probably be easily visible and hence vandalized, making the vandalizer anonymous. If storing somewhere else, where the vandalizer didn't have access, he could vandalize the camera but I would at least be able identify him or her, which is the main aim. A solution would be a wireless AC camera, that could be vandalized without getting the pictures taken destroyed (because they got stored somewhere else), but getting AC current might be quite a hassle, not to mention that if the vandalizer saw the cable, he/she might infer that he/she has been wirelessly recorded and might feel tempted to follow the cable trying to find where the control center is. How much would an acid battery last if I connected it to one of those 12V wireless cameras? That might be an option if it lasted 1-2 weeks, but it has the downside of making the whole setup much more easily spottable, increasing the probability of being destroyed. On the other hand, I have serious concerns thinking about how, when he/she spotted the whole setup, might react furiously hitting the battery or something that put the whole thing into fire.

 

A hypothetical solution would be a camera like the "bird watching" one, powered by AA batteries that last long (I still don't know how they can last so long), but that only enabled the wireless function, after having taken X pictures into its internal memory, to dump them to the control center. Thus, the wireless transfer would only be briefly activated from time to time, which should not put too much "strain" on the batteries.

[Squiffy 0]

What's the distance between the target location and the 'control' location? What resolution images would you require?

 

I also suggest using a sealed lead-acid battery, which could be buried to make it more covert.

[gadgetbest 0]

What's the distance between the target location and the 'control' location?

 

I guess it's close enough to allow a short range wireless device to connect properly. It's probably less than 20 meters.

What resolution images would you require?

 

With low resolution it would be enough. Just enough to be able to recognize a person you see often.

I also suggest using a sealed lead-acid battery, which could be buried to make it more covert.

 

That would probably be more hassle than leading the 12V cable to the spot where the camera is going to be recording. In any case, the lead-acid battery seems to be a pretty useful device with many applications: how can I calculate, given the specs of a lead-acid battery and given the specs of a device, how much it's going to last? And how long does it take for one of these batteries to get charged?

[Squiffy 0]

> It's probably less than 20 meters.

 

This means a wireless link can be low power which is good.

 

> With low resolution it would be enough

 

Therefore a CMOS camera will be adequate, this again is good as power consumption is lower than for a CCD camera.

 

 

> how can I calculate, given the specs of a lead-acid battery and given the specs of a device, how much it's going to last?

 

You should divide the Ah rating of the battery by the current consumption of the devices used. E.g. a 10Ah battery with a total current being used of 500mA should theoretically give twenty hours. Actually for a useable voltage it will be slightly less than that, perhaps 19 hours.

 

> And how long does it take for one of these batteries to get charged?

It depends on the Ah rating (the current capacity) of the battery and the charge rate of the charger used. Note that sealed lead-acid batteries require constant voltage chargers, so you can't just use a typical car battery charger.

[dopalgangr 1]

Dont over think it, these are expensive and you can probably shop around to find it cheaper but they have a range of 2 miles http://www.hunting-cams.com/p-21-buckeye-cam-orion-pc-base-camera-system-includes-1-camera-pc-base.aspx

 

Thats the complete kit though. The cell phone jobs are cheaper but they require a monthly subscription. The battery requirement is your main problem. I could probably whip up a cheaper solution with a little time, whats the range from your camera location to the computer?

 

Also, if you can take a picture of the area that you will mount the camera from the first point you would see the camera that would be helpful. Is there any lights at all in the area of concern?

[Soundy 1]

The one other concern with wireless is, what's in the way? It may only be 20 meters, but I suspect that's not open air. Are there walls? And if so, what kind? Wood, steel stud, concrete? Each of these will successively have an adverse affect on your range...

[Squiffy 0]

Other factors to consider with wireless range are the frequency used, gain of the antennae and if the receiving location has windows. Obviously line of sight is preferable but you can still often get acceptable results because microwave frequencies will actually 'bounce' around. Also bear in mind that if using the 2.4GHz spectrum you may encounter interference from WLANs and microwave ovens.

[gadgetbest 0]

Thank you very much for your replies. I will quote each of them and I will answer.

 

> And how long does it take for one of these batteries to get charged?

It depends on the Ah rating (the current capacity) of the battery and the charge rate of the charger used. Note that sealed lead-acid batteries require constant voltage chargers, so you can't just use a typical car battery charger.

 

Maybe the sealed lead acid battery idea isn't so bad. After all, even if the intruder gets angry when he/she sees the camera and begins hitting the battery, I don't think it will burst into flames or anything like that (am I right?). That said, how much energy do most wireless CMOS cams spend as a general rule? Less than 200 mAh? If that were the case, would I have to get a 30 Ah battery if I want to be able to recharge once a week? As far as how to connect it to the battery and how to charge the battery, I have no idea, do these kind of batteries come with a plugin or do you have to do the connection from scratch?

On the other hand, the "motion detecting" mechanism doesn't seem to be related to battery life, because it isn't implemented at the camera level but at the receptor level, is that correct?

 

 

Dont over think it, these are expensive and you can probably shop around to find it cheaper but they have a range of 2 miles

 

That looks like an awesome equipment but it's way to expensive. I was thinking that, for the time being, I could buy a normal wireless spy cam + receiver that records when it detects movement in a SD card. These kind of receptors, if I am not mistaken, come with a Video OUT connection, which I could use in the future to connect one long distance emitter, that could be useful, for instance, to watch the camera from somewhere else (at work, for instance) located a few miles away. These devices don't seem very expensive: the 3W one is around 400 bucks and it theoretically can reach up to 7 miles, that is probably without obstacles in between, but with some obstacles what could it get? 2 miles maybe? In any case, these can be connected to any wireless cam + receptor set with video out, right?

 

I am speaking about the trc12g section in vfmstore (I cannot paste the link).

 

 

The one other concern with wireless is, what's in the way? It may only be 20 meters, but I suspect that's not open air. Are there walls? And if so, what kind? Wood, steel stud, concrete? Each of these will successively have an adverse affect on your range...

 

Perhaps a couple of walls or something like that. I think that the 20-50 range would be perfectly suitable. In any case, most wireless cameras seem to offer 100 ft or more, don't they?

[Squiffy 0]

> I don't think it will burst into flames or anything like that

 

If the power connections are shorted then that may possibly happen. The construction of the batteries are usually quite robust and would require considerable effort to break apart.

 

> how much energy do most wireless CMOS cams spend as a general rule

 

It depends on the model obviously but on average about 50ma. However once you add infra-red LEDs and a transmitter it's going to be about 250ma. The infra-red LEDs should have a sensor so that they're only working when light becomes low enough, this should considerably extend battery life.

 

> would I have to get a 30 Ah battery if I want to be able to recharge once a week?

 

For 200ma that should be almost adequate. If you bear in mind that the duty cycle of the IR LEDs will not be 100% then it may well be more than adequate. It's better to have two batteries and simply exchange them rather than the one and having to wait for it to recharge.

 

Note that sealed lead-acid batteries should NOT be left in a state of discharge for long, otherwise they'll become useless.

 

 

> motion detecting" mechanism doesn't seem to be related to battery life

If done at source, say, using a PIR alarm it can save consumption but then you'll have to factor in the consumption of the PIR and associated circuitry. Having the camera switch on only when the PIR is activated can be problematic, as a camera and transmitter will often require a few seconds to give a stable picture.

 

As for extending microwave frequency range then rather than just transmitting higher power, it's better to use a high gain receive aerial with a pre-amp mounted directly to the aerial, which reduces coaxial cable losses which are substantial at microwave frequencies.

 

To give you some idea of the advantage of line-of-sight, law enforcement helicopters often use just 500mW but have a range of around 50 miles.

[zmxtech 0]

solar panel, charger and battery and an AXIS m1011-w or a 206-207 wireless will do the job well, motion detection built in.

If you want IR then I would use an ACTI IR IP camera good bang for buck

1311 etc

 

The M series you can even record a warning message as the light comes on.

 

z