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A question to the IP-Camera community about UPS...

Asteve

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Admission: I'm not actually an IP-Camera user... but I believe I have a similar problem to that which I expect IP-Camera installers are likely to regularly tackle.

Assumption: I know it is common for network routers, modems and switches to require a 12V input... It's also common among other esoteric low-power equipment such as single board computers etc. I'm assuming it is also common for IP cameras to require 12V DC power.

I'm interested in neat and efficient solutions for UPS (Uninterruptible Power Supplies). I imagine this is important so IP Cameras continue to operate if mains power is cut... and, preferably, continue to operate for as long as is practical while mains power remains out. I would like my network infrastructure to remain operational - even in the case of a power outage. I would like this to be automatically monitored by a computer... so, in the event of a power failure, automated action can be taken to alert relevant people. All the devices I care about require 12v DC - and are rated to draw up-to either 2A or 2.5A - and draw <1A most of the time. In the past, I've deployed a big UPS (APC or Eton) that, when the power goes out, uses an inverter to provide mains-voltage AC from the UPS battery - then for that to power 10 small PSUs - one for each 12V (low average current) device.

It strikes me that where a UPS takes battery-voltage DC to produce Mains Voltage AC to separately run 10 PSUs to provide 10 feeds of 12V is clunky/cumbersome - and must be inefficient - both requiring a larger battery and occupying much more space. It strikes me that it would be much neater if I had an UPS that provided 10 outputs of 12v... each capable of delivering up-to, say, 3A.

I've discovered very small-scale "UPS" available in the UK - but they don't support many 12v outputs (so I'd need a separate UPS for each 1 or 2 devices) and none seem to allow their status to be automatically monitored from a computer... which makes it difficult to implement systems that react to power failures in an optimum way. When I look for UPS with about ten 12V outputs - every path seems to lead to Alibaba... for brands like Marsriva (KP7/KP9); Fanshine (FS10A); aSNC (#47) and SKE (POE-12W-48v). Perhaps I shouldn't have been surprised - but I discovered it was very difficult to find detailed specifications... and even more difficult to source evaluation samples. These product names seem to have been bandied around on the internet for several years - but the hardware seems to remain illusive.

My questions for IP-Camera and CCTV experts:
  • Do you often find, when doing installations, that you want/need to provide UPS backed power to a bunch of 12V devices?
  • What is your UPS approach...
    • Do you always buy a big conventional (e.g. APC/Eaton) UPS that provides reliable mains - then plug lots of mains-voltage PSUs, one for each individual device, into that?
    • Do you use (many) small-scale "Mini DC UPS" - one for each (or each pair) of 12v device(s).
    • Can you recommend any DC UPS that supports several (ideally 10+) 12V devices simultaneously.
  • Which brands/models of UPS do you turn to when the priorities are:
    • Reliability of operation;
    • Automatable notifications about power-failure events (remote monitoring);
    • Maximising runtime to provide continuous services during the longest power cuts... while also caring about cost and value.
  • What battery technology do you prefer -- Lead acid, LiFEPO4, Lithium NMC/LCO/LMO/NCA/LTO - or something else?
  • Do you use off-the shelf UPS - or do you build custom solutions from standard components (e.g. battery; charger; voltage regulator - etc?)
I would be genuinely interested in answers from the perspective of people who work lots with IP cameras - especially those working in CCTV contexts.
 
I will shock you right now but more than 90% of IP Camera installations are not wired with 12VDC input but via PoE

1 PoE switch which is roughly 220AVC -> 51-52VDC adapter powered, gives all the power and networking to IpCameras connected to it.

So when you are in search for UPS with that installation type, usually camera specs arent even needed. You just use the max PoE switch power usage. And define UPS for max usage x uptime needed.

The more uptime, the more expensive it is. SImple as that, there is no cheap and good.

Every switch has a shared maximum power output and power input. And you can calculate UPS using a single device, instead for multiple cameras.

Cheers,
 
Thanks for the reply... IP Cameras using POE makes sense.... though, if only 90% use POE - there's some prospect that some still use 12V? :-) I would have guessed that (for small sites, at least) network connectivity might also coincide with the need to keep routers and switches active during a power outage - in order to keep remote monitoring active?

I appreciate the argument that uptime and expense should be expected to be positively correlated. I'm not yet ready to accept that every solution would necessarily be prohibitively expensive - just because budget restraint is required. I'm curious about the strategies typically adopted - given that applications like CCTV may deliver maximum remote-monitoring value in circumstances where the power is out. Is it usual to have a big UPS (APC/Eaton etc.) with battery-backed mains output... powering one conventional PSU for each (12v) switch/router/hub required to maintain network connectivity during a power outage? It strikes me that a far better approach would be to use a DC UPS - and have one reliable supply for all the critical (12v powered) network infrastructure... and for that to depend upon a shared pool of battery resources. If neither the inverter in the UPS (to produce mains AC from battery DC) nor the mains-PSUs (one per 12v-powered piece of network infrastructure) are strictly necessary - surely it would improve efficiency to eliminate them?

I wonder... having recently discovered "PoE to DC 12V 3A Splitters" - if this is the mainstream approach you suggest? If there were to be reliable PoE power at 48v - and a splitter could reliably power a 12V device from it - then that would be a great solution. I'm not very familiar with PoE... but know there needs to be a PoE injector that acts as the source of power for PoE devices. Is it more common to choose PoE injectors that include battery backup - or to use PoE injectors without batteries - and plug them into conventional UPS (with an inverter - providing battery-backed mains electricity to the PoE injector)?

Where I've searched for DC UPS online (both 12V and PoE 48v) I've struggled to find products (with batteries) that look trustworthy to me. I can find lots of Chinese looking devices - typical capacities are smaller than I'd need; specifications of the larger capacity ones look suspicious - and samples of those are very difficult to acquire for evaluation.

Say I've 10 devices - each 12v; each rated to a maximum current of 2.5A - but typically draw < ~1A. Simplistic calculation suggests I'd need something that is rated to provide up-to 300w (maybe a little more as the PoE splitters won't be 100% efficient)... but that average demand should be < ~120w. If I target ~4 hours runtime - that hints at needing ~500wh from batteries - obviously proportionally more required for longer runtimes. Are there any credible products that will deliver this... without introducing an inverter with mains-voltage output powered by UPS batteries?
 
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IP Cameras using POE makes sense.... though, if only 90% use POE - there's some prospect that some still use 12V? :-) I would have guessed that (for small sites, at least)
No, the oney connected to 12v and network are usually bad practice, considering we have PoE switches for dacades.
So lets put it like this:


Power backup for IP cameras should always backup entire switch. Switch have its own adapter 220V -> 51VDC
Power backup for NVR same as well, it got its own power adapter from 220V to 12VDC up to 3.3Amps

You also have a router which also have its own adapter from 220V -> 9-36VDX depends on a model

So i would rather go with 220AC ups rather than DC

Cheers,
 
Many thanks. I guess I'm not surprised that the mainstream approach is to buy a conventional UPS providing mains output - then plug mains-UPS for devices into it. My intuition still tells me that this design is far from optimal - but it does look challenging to put together a cost-effective solution using a different approach. My head had been turned with the proliferation of "Mini DC UPS" - and thought off-the-shelf DC-output UPS might now be a viable option.
 
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