Phasing out home phones

[#1]

@bgiles 

Just checked, the battery I fitted was a Powersonic PG-12V9, same physical size as the 7.2Ah one I believe, and roughly twice the physical size of the original 4.5Ah one.

[#2]

When considering battery capacity you need to also look at the rate. Most small batteries are rated at the 20hr rate. In other words a 7.2Ah battery should supply 7.2/20=0.36A for 20 hrs.. At higher discharge currents the capacity is less, at lower currents it increases.

[#3]

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@Mr_Paul wrote:

@Baldrick1 

Assuming for a moment that "VA" as the same as Watts - I know that it isn't, but let's ignore Power Factor for now - then that capacity at a drain of 15 Watts, should be able to be powered for almost 24 hours, shouldn't it

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No - despite some/many manufacturers referring to VA as 'capacity' - that is NOT its 'energy capacity'.

The VA or Watts rating is maximum power draw rate - i.e. maximum watts (or maximum Amps if you divide by output voltage).

The energy capacity is completely different and really should be given as 'Watt-hours' (at various different power/current drain rates).

https://en.wikipedia.org/wiki/Kilowatt-hour#Distinction_between_kWh_(energy)_and_kW_(power)

Example UPS specification: Where this typical (small) 700 VA  420 Watt 240V mains UPS says it can run for 47 minutes at 60 Watts output rate...

BR700ELCD-UK - Backup UPS Systems | CyberPower

- that's actually just a 47 Watt-hour energy capacity (60 Watts x (47 mins / 60 mins) hours) at that 60 W power output - which would then last about an hour if you drew power at say 47 Watts - or 1 hour 34 minutes at say 30 Watts drain - etc, etc.

As with most batteries the 'Watt-hours' capacity does vary to some degree depending on the current/power draw rate (dropping considerably at high drain rates) - slow/low drain giving higher energy capacity efficiency, fast/high drain resulting in lower energy capacity efficiency...

The spec's for the above device say just 1.5 minutes run time (!) at its maximum 420 Watts output - which is just 10.5 Watt-hours useful energy at that maximum power draw rate - only 22% of the energy capacity it gives at a 60 Watt power output rate.

[#4]

Thinking about the options I came across portable camping power supplies such as this https://www.amazon.co.uk/ALLPOWERS-Portable-Generator-Emergency-Technology/dp/B081DSC1HD. Ok they are relatively expensive but my initial thoughts are that one of these or similar/adapting this principle with solar panel charging would keep an ONT plus router continuously powered. The battery should see it through the night and during daylight hours there's every chance that the solar panel would keep both the kit working and recharge the battery.

[#5]

@Baldrick1

I guess individuals have to decide how important maintaining a Broadband connection (and VoIP) is to them, and if critical, they’ll want to go for the longest run-time possible, so something like you’ve suggested would be ideal.

I’ve just done another run-time test using my spare UPS, and it gave me similar result to last time. Maybe having switching-mode power supplies connected does have a greater impact, as you suggest. Obviously adding a ONT into the equation would reduce run-time further. 

I would imagine a modest UPS would provide an acceptable level of backup power for the majority of users, it certainly is for me.

Here are my results;

Model: APC Back-UPS CS350
Advertise run-time: 350 VA - 13.2 minutes
Installed battery: CSB 12V 7.2Ah
Recharge cycles: 1 (new in 2022, and unused since)

Connected devices
Router: Plusnet Hub One (Sagemcom)
Running wattage: 6.1W (not connected to line)
Power supply type: Switching-mode

DECT Base: BT4600
Running wattage: 1.9W (handset charging)
Running wattage: 1.2W (NO charging handset)
Power supply type: Switching-mode

Combined wattage: 8.0/7.3W

UPS run-time @ 7.3W load: 65 minutes

[#6]

I've just done a further test, having left the UPS on charge overnight, and conclude that it may not have been fully charged when I did the test yesterday.

The results are quite reassuring, as they imply my SoGEA connection, (and associated VoIP service), will continue to run until the backup power at the FTTC cabinet fails, which @JSHarris says is as little as 30 minutes.

Model: APC Back-UPS CS350
Installed battery: CSB 12V 7.2Ah

Connected devices
Router: Plusnet Hub One (Sagemcom)
DECT Base: BT4600
Combined wattage: 7.3W

UPS run-time @ 7.3W load: 100 minutes

[#7]

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@Baldrick1 wrote:

Thinking about the options I came across portable camping power supplies such as this https://www.amazon.co.uk/ALLPOWERS-Portable-Generator-Emergency-Technology/dp/B081DSC1HD. Ok they ... initial thoughts are that one of these or similar/adapting this principle with solar panel charging would keep an ONT plus router continuously powered. The battery should see it through the night and during daylight hours there's every chance that the solar panel would keep both the kit working and recharge the battery.

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Just a few observations...

As you may already appreciate - it's not an actual 'UPS' - i.e. it isn't designed for permanently connection, nor to instantly switch-over without 'interruption' of power. 

I'd caution against buying that particular item - its having a relatively poor 62% 5 star & the quite significant 11% 1 star reviews - of course, there are other similar with better reviews.

Note, the solar panel isn't included in the price - it has to be bought as an extra.

I'd seriously question whether the solar panel would recharge or maintain power particularly in the winter months when you're more likely to need it during mains power-cuts - the Sun being very low, cloudy and short daylight hours during winter.

[#8]

@Mark280 

I accept every point you make. It was the principle that I was exploring. I was really seeking an alternative to a small petrol driver generator. I have 4kWhp of solar panels on my roof and there are winter days when I barely generate 1 kWh, but that is the exception. It occurred to me that a small battery powered inverter that could be charged from solar, mains or car battery could at least provide power for a long period, be it with a bit of jury rigging. I can live with needing to manually connect an emergency supply.

The problem with many a UPS is that they do not have ‘black start’ capability, that is, they have to be constantly on line. This might be a price worth paying for time to shut down a computer safely and/or to make an emergency phone call, but I was exploring options for longer term support.

[#9]

@Baldrick1 

Having been in the IT infrastructure sector for many years, I've always followed the principle of having UPS backup for IT equipment.

Whilst, as I have shown, a UPS only provides a limited amount of time, surely used in conjunction with a power station like you've suggested, when experiencing a power cut, the user would have time to move the power station adjacent to the UPS, and plug the UPS into it. This would then provide a significant period of backup for those users who are completely dependent on an Internet connection, without losing the connection at any point?

[#10]

How many UPS users here ALSO connect a communication cable (USB, RS232, or Ethernet) from their UPS to their computer, to automatically perform a controlled and managed system shutdown when the remaining UPS battery has almost reached exhaustion ?

Each of my desktop machines have their own UPS - as the mains power here regularly glitches.

I even have my pfSense router do a controlled shutdown, when it's UPS remaining battery run time reaches five minutes.  😎

[#11]

Whilst I do have a comms cable between my desktop PC and UPS, the desktop PC is rarely on, and if it were, it would be the FIRST thing I'd shut down in order to preserve the UPS battery life, thereby maintaining the router and VoIP connections as long as possible.

I would then switch to using a laptop during the outage.

[#12]

I have my desktops automatically shut down, when the power cut gets to ten minutes - as it's likely to be a prolonged outage.

My pfSense router has it's own UPS, and does a controlled shutdown at 5 minutes remaining battery.

My modem and DECT phone base, have their own UPS, which runs until the battery gives up.

[#13]

@Anonymous 

Seems like you have almost all scenarios covered, but I'm not sure how many users would go to that amount of effort;

1. Desktop: Dedicated UPS

2. Router: Built-in UPS

3. DECT: Dedicated UPS

Sounds like your connection is VERY important to you. 💪

I'm also guessing you're currently on FTTC or SoGEA, as no mention of a UPS for the ONT?

[#14]

Due to frequent power cuts here, I got fed up spending all my time rebuilding PCs damaged by power surges - I once lost 7 PCs in one day.  Having individual UPSs for each desktop has solved that problem.

I had to UPS the modem, because my DSL connection is on a long line and ANY glitch would cause my line DLM to crash my "IP profile" and never recover - without intervention of Plusnet scheduling a line reset.  It was an utmost priority to keep the modem running 24/7/365 to maintain an error free connection and a happy DLM.  Since having move to SoGEA my DLM seems to be more tolerant, and so far has recovered after modem swaps, and extended power outages.

I had to UPS the DECT phone base, because of non-existent mobile coverage, so needed to keep the landline phone available as long as possible in the event of emergencies because I'm four miles from civilisation.  I also had a spare passive analogue handset next to my master socket, which could be plugged in once the UPS had expired.  Both of these measures are now redundant since I recently changed from FTTC+POTS to SoGEA+VoIP, so my 'landline' now fails once the router goes down, but in the last year I can now just about get a 2G signal on the O2 network since EE switched off their nearest 3G tower ?.

I then put a UPS on my router, because a power cut/surge destroyed my router, days before my wife's funeral, my kids were trying to do college work from home, so I had a massive problem of having no internet at a very stressful time !.  Unfortunately because I run pfSense with multiple VLANs, multiple VPNs, IPv6 tunnels, etc,  it wasn't simply a matter of substituting a commercial router, and needed a new ITX dual-LAN motherboard and to rebuild pfSense from configuration backups (which luckily I had a recent copy).

[#15]

@Anonymous 

Your example, along with @JSHarris, (and others land line dependant users), are prime examples of the importance of having backup power plan at home.

Unfortunately, if on FTTC and SoGEA, our best thought through plans are still dependent on backup power being provided in the cabinet, and we still have no idea;

1. If all the cabinets have backup power.

2. How long it will last in the event of power failure.

JSHarris' experience is about 30 minutes, just enough time to ring a friend to let them know you'll be uncontactable very soon!