Denfender DVR and cam consumption and low voltage behaviour

[Kilowatt 0]

Hi thanks to read,

 

This is an informative post for those just curious about power supply requirements and consumption. I'm almost finished to install my surveillance system based on the 21325 kit from Defender. The DVR model is the 21150 and the included four cameras bears the model #21320. I wish to have this system to be battery backed in case of power outage and found this kit to be well suited for such application. I was about to buy an expensive voltage stabilizer to power this kit to compensate for the dropping voltage when the battery bank is discharging (down to 10.5V, cut-off point of my 12V distribution system). I decided not to buy this stabilizer until i do some tests with a variable power supply. Well i received the kit this week and today i've made some tests... here's the results:

 

1st part- Low voltage operation:

 

With all the cameras and the DVR (in normal record mode) connected to the same power source, my variable power supply, started from 13V and slowly got the voltage down to simulate a battery discharging (fast!) down to 11V. From there, i lowered the voltage in 0.1V steps allowing 5 minutes between each steps to monitor the behaviour of the DVR and cameras. The lower limit found is exactly the cut-off point of my 12V system, 10.5V. At that voltage, all the cameras were operating just fine. The DVR did fine for one minute and the HDD led then stopped flashing and then no recording, although i could still see the live cameras. A try to do a "record search" to retrieve some recordings gave me the message from the firmware "No HDD Found". One interesting thing to note is that when i resumed normal 12V voltage, 20 seconds after, the DVR rebooted itself and was back to record mode! By experimenting, found that the lowest voltage at wich the DVR remains stable without shuting down it's HDD is 10.6V. Now i know that battery backup is really a possibility with this kit.

 

2nd part- Consumption (@12V):

 

Camera (each):

70mA in normal lighting

260mA in darkness (infrared lighting on).

Note that 500mA is specified on the camera's label...probably when combined with the IR filter actuator that operates for a fraction of a second...yes.

Overall this is really good news since i've bought the AGM batteries for my 12V distribution system according to the 500mA specifications. I will get more run time than i've planned wich is good.

 

DVR unit:

ramping up from 0 to 1.5A at power up (when the HDD is gaining speed) and then stabilize in the range of 630~660mA in normal record mode. Once again this is good since i've planned for 3X this consumption initially.

 

If you consider acquiring a CCTV 960H battery backed surveillance system, i hope that this might be helpfull to you.

 

Thanks again to read.