How to achieve uninterrupted power supply in Indian conditions for small Wireless IP CCTV systems ?

 By wireless IP CCTV system, we mean the networking is wireless, but the power is wired wither by default or to augment the camera's inbuilt battery.

A study of Xiaomi and Sricam wireless cameras points to the following observations

1. All these cameras are 5V USB powered and draw only 0.3A of current (no IR) when in operation (0.4AA during startup or when the inbuilt motor is used to pan or tilt the camera) with mnotioin-triggered recording. This means a typical power average consumption of 1.5W only. 12V cameras are more of regular wired with wireless functionality baked in devices from Hikvision brand.
2. Their are no NVRs. The device connects through 2.4Ghz Wifi Router or some type of base station to the cloud directly and we observe the following:

• You get rarely a 5V 2.4Ghz 802.11n router. The only option we could find is from Mercusys (5V-0.6A or 3W), but this does not support USB modem. Travel routers (tplink MR3020) use 2-3W, but are not suitable because of poor range. 

• Almost all other typical fixed/mobile broadband with modem (ADSL, ONT needs 12V, 0.5A or 12V, 1Aor 9V-0.6A which means 6-12W atleast
• If a separate modem is needed, we can get the compact Tp-link TLMR3020, disable wifi and again run the broadband show in about 3W maximum. 

 

So if we consider a 4 wireless camera, we need to atleast handle 12W [6W (Router+Broadband Modem) +  6W (4 x1.5) for cameras]. 

We also observed the following:

1. The Best 12V DC-DC UPS (Resonate, Cuzor) brands give maximum 3-4 hours backup time on 22wH battery to typical 12V WiFi Routers. 
2. The Best 5V  USB DC-DC UPS (Regaldream) brand gives upto 12 hours of backup time for Xiaomi/Sricam wireless CCTV cameras . Even if IR is enabled full time and cameras use full 5W rating, it will still give nearly 4 hours of backup.
3. We expect 4-6 hours on the 5V energy efficient Mercusys broadband routers. If Wifi router UPS goes down, the only functionality impacted is cloud upload and remote access (the cameras will continue to work and record on the onboard SD card  storage) and that too till the power returns

Therefore using above, we can make a system that can support the long 4-8 hour outages in summer season in many Indian cities. We *recommend using energy efficient 5V devices AFAP (both cameras AND Wifi Routers) and Regaldream 5V DC-DC UPS which shows considerable potential as secondary source part from emergency source. The cost is also not impractical (they cost less than Cuzor and Resonate), are micro USB compatible (direct fit for cameras without needing hard to find adaptors), and fit easily in a 5x5 PVC Indoor/Outdoor junction boxes that are used with CCTV cameras for mounting. We have already saved a lot of money by removing the NVR & some wiring associated with wired implementations (Its possible to setup such cameras at Rs. 5000 per camera in India, which is almost 1/3rd - 1/4th the cost of wired IP camera setups)

Therefore from power angle, we think that this is a fairly practical solution. And it will even scale to  8/16 cameras, all with motion triggered recording and retain the system backup time in case of load-shedding. No inverter-UPS or big UPS required (if its there for other applications,  use it and eliminate DC-DC UPS cost also).

Alternatively,  because our power draw is so less (12W) for a 4-camera setup, it seems attractive to centralize power supply & use our uber-popular and compact UPS of 600-650VA capacity like APC Back-UPS 600 but they do not support continued run beyond 2 hours on paper, even on light loads like 12W and even if no load shutdown is disabled. What we observed is that this limit is hit a little after 1 hour, when the UPS shuts down despite having juice in battery and has to be manually turned on (and once you do, it will happily run for another 1+ hour cycle). We have no idea if other brand UPS behaves any differently. 

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee