topic Re: UPS required for domestic use in Tech Help - Software/Hardware etc

UPS required for domestic use

Surfer — Mon, 13 Oct 2025 09:59:22 GMT

Being in a rural area, we often have power breaks especially during the winter months with some lasting several hours. I bought a cheap Chinese made UPS 18 months ago and although it worked okay last year, this year it only last about 30 minutes and gave up.

We are a domestic premise and we have no phone line. Mobile signal is very poor and very slow so we rely on the router to make calls. I am not sure of the wattage for the router, but laptop is new Samsung Galaxy book. Probably combined wattage about 40watt.

Ideally we would like an UPS that will last several hours, but not sure how to work out the power rating for UPS to last several or more hours. Can anyone please advise? Thanks.

Re: UPS required for domestic use

bmc — Mon, 13 Oct 2025 10:02:11 GMT

@Surfer

Can't help with UPS but are you on FTTC or FTTP?

FTTC will only last as long as the battery in the cabinet - often less than an hour.

Full Fibre is far better as the fibre goes all the way back to a main exchange which will have it's own power backup,

Brian

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 11:08:38 GMT

We do not have full fibre to the house, only to the cabinet. The exchange is nearly 2 miles away by road. Previously when we have had a power break, we have been able to use the Internet for a couple of hours. It is only a small village of about 30-40 homes if that, but appreciate that the exchange will cover a much larger area?

Re: UPS required for domestic use

mystreet1 — Mon, 13 Oct 2025 11:21:39 GMT

https://www.broadbandbuyer.com/store/surge-protection-ups/uninterruptible-power-supply/?t=1048&sort=1
This page gives you some idea of the price range. At the end of the day, it's down to budget against up time needed.

Re: UPS required for domestic use

Baldrick1 — Mon, 13 Oct 2025 11:42:07 GMT

@Surfer

The Plusnet Hub 2 load is10W.

Doesn't your Galaxy book have a battery? If so, then you need to take into consideration the charging current when the battery goes flat, not the running power when on its battery.

You need to look at the Whr rating of UPSs’ battery, NOT the much more publicised kVa rating of the UPS. Then your calculation is simple: A UPS with a 40Whr rated battery should feed a 40W load for approximately an hour, 80 Whr battery, 2 hours, 200Whr battery 5 hours etc.

I keep an Anker camping UPS for these occasions. As well as providing back up power it also has a light, USB outputs and a 12V output.

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 12:35:52 GMT

Thanks. Not sure why I added the laptop into the equation. We only need to keep the router powered on. If we look at a UPS with a wattage of about 500w that should easily power the router for several or more hours? Is that correct? Also not sure which brand is best, type of battery i.e. lithium of sealed lead acide and whether the battery should be replaceable?

Re: UPS required for domestic use

Baldrick1 — Mon, 13 Oct 2025 13:08:40 GMT

@Surfer

NO! Whilst it might be adequate, having a rating of 500W means that it is rated to provide an output of 500W, but doesn't specify for how long. It may be for 20 seconds so that a computer can be shut down, it might be 20 hours.

It's the WHr capacity of the battery that you need to know to keep a router providing power for many hours. You don't need a UPS that's capable of providing a lot of power for a short period. These are designed to keep computer systems powered until they can be shut down in an orderly manner to avoid data loss through crashing out whilst transferring data.

You need to look at full specification and look for the WHr capacity of the battery, as explained in my previous post.

Re: UPS required for domestic use

Townman — Mon, 13 Oct 2025 13:32:23 GMT

@Baldrick1

This might be a convenient opportunity to explore general considerations of UPS backup for power cuts.

In the context of keeping comms going through what might be an extended power cut, it seems to me that rather than expecting a UPS pack to push out 240v AC to power transformers to bring the power back down to the 5V / 12V / 19V DC needed for ONTs, routers and laptops (etc) it would be more beneficial to have a UPS which delivered these voltages and suitable power leads to replace the power-brick connections.

Do you know of any such?

Transforming up / down, DC to AC to DC will incur some level of power loss with the UPS and each power-brick, which if avoided might yield somewhat longer operation.

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 13:43:48 GMT

Apologies as I am very ignorant on UPS, technical specifications and out of my depth on the subject so not sure about anything. When reading specifications it seems in many cases Whr is not mentioned, just the wattage capacity i.e. 540w? VA capacity is mentioned i.e. 900.

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 13:58:37 GMT

Would a unit like this be suitable for a load of 20w for several hours? See HERE

Re: UPS required for domestic use

MisterW — Mon, 13 Oct 2025 14:11:24 GMT

@Surfer from the description

720W with 9 min runtime at half load

Hence 360*9/60 = 54WHr

So you'd expect approx 2.5 hrs at 20w

This https://www.amazon.co.uk/APC-BACK-UPS-BE850G2-UK-Uninterruptible-Protected/dp/B0828G42KN is a similar price and does quote typical run time of 170min at 20w.

Its also a name (APC) I've heard of and used when I worked in the Industrial Automation field. Probably still made in China though...

Re: UPS required for domestic use

Townman — Mon, 13 Oct 2025 14:15:07 GMT

@Surfer wrote:

Apologies as I am very ignorant on UPS, technical specifications and out of my depth on the subject ...

No need to apologise, it is a tad complex as it is all to do with power capacity and power loading ... see APC’s Smart-UPS On-line delivers innovative features - APC Canada

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 15:16:26 GMT

To be honest i don't understand the calculation 360*9/60 = 54WHr. What do they represent? Thanks. Can I therefore assume an run time of at least 4 hours if only the 10w router is connected? Thanks

Re: UPS required for domestic use

IMM — Mon, 13 Oct 2025 15:20:12 GMT

I wonder whether we are looking for the wrong thing here.

As I understand it, the main design intention of a traditional UPS is to give backup power to a device (typically with spinning disks) for just long enough for it to safely shut itself down with no damage to memory or a disk crash.

I note that there are items on the market that typically go under the description of "Power Bank", Power Station" or similar - eg Bluetti on Amazon these seem to be aimed at either providing power for a weekend of camping or providing backup power in the case of power cuts. They generally have much more battery capacity. Some have "pass through power" so that they can be inline (similar to an UPS) so that they switch to battery power automatically - some even claim to be fast enough to act as an UPS.

For power cut backup, I wonder whether fast switching is needed at the start of the power cut - If there is a short dip followed by a reboot, does it really matter?

Ian

Re: UPS required for domestic use

Baldrick1 — Mon, 13 Oct 2025 15:55:53 GMT

@Townman wrote:

@Baldrick1

This might be a convenient opportunity to explore general considerations of UPS backup for power cuts.

In the context of keeping comms going through what might be an extended power cut, it seems to me that rather than expecting a UPS pack to push out 240v AC to power transformers to bring the power back down to the 5V / 12V / 19V DC needed for ONTs, routers and laptops (etc) it would be more beneficial to have a UPS which delivered these voltages and suitable power leads to replace the power-brick connections.

Do you know of any such?

Transforming up / down, DC to AC to DC will incur some level of power loss with the UPS and each power-brick, which if avoided might yield somewhat longer operation.

Yes, I think a dedicated post is overdue. I have certainly seen LV devices but their battery capacity needs more investigation.

My set up is non standard as my ONT is in a different part of the house to the router. Rather than complicate the matter I have two UPSs. The Anker one I mentioned earlier has sufficient grunt (256WHr) to keep both my Router and cordless phone basestation going for many hours. The ONT, which only consumes a watt or two is fed from a APC CP12036Li Back up UPS, which has a 20WHr Lithium battery, which should keep the ONT up all day, This is connected in line with the ONT PSU.

The camping Antek unit is very adaptable. It can be recharged from the mains, or the car if out and about. It is also compatible with a solar panel. It can also be used to recharge the APC if necessary.

Not the cheapest solution I know.

Re: UPS required for domestic use

Surfer — Mon, 13 Oct 2025 17:01:10 GMT

Thanks for the many helpful replies. If the ACP 850VA/520w lasts 170 minutes it gives the impression that the 1050VA/600w should last longer albeit only about an hour? Is my reasoning flawed again? https://www.amazon.co.uk/APC-BACK-UPS-BE850G2-UK-Uninterruptible-Protected/dp/B0DFQHLY79?th=1

Re: UPS required for domestic use

mystreet1 — Mon, 13 Oct 2025 17:20:39 GMT

This post mentioned something about various outputs

https://community.plus.net/t5/Tech-Help-Software-Hardware-etc/Testing-the-backup-time-for-a-cheap-DC-UPS-for-a-Plusnet-Router/td-p/1979846#M96537

Re: UPS required for domestic use

MisterW — Mon, 13 Oct 2025 17:34:01 GMT

@Surfer not necessarily , just check the APC site ,https://www.se.com/uk/en/search/?q=be850g2-uk look at the product data sheets and the runtime curves. In fact the 850nis better than the 1050

Re: UPS required for domestic use

Baldrick1 — Wed, 15 Oct 2025 13:30:38 GMT

Moderator's note:
Thread moved from Everything Else to Tech Help

Re: UPS required for domestic use

Baldrick1 — Wed, 15 Oct 2025 14:52:04 GMT

I have divided this post into sections:

Low Voltage Battery Back Up
Computer UPSs.
Alternative UPSs

1. Low Voltage Battery Back Up

My recommendation is to forget getting a 240V ac Uninterruptible Power Supply (UPS) and get a low voltage (Battery Back Up Unit (BBUU). These replace the route (and VoIP ATA power supply if needed) with a battery backed low voltage output. This is the same output voltage as a, for example, router power supply, except that when the power fails, the battery automatically takes over.

The Unit to choose depends on how long you wish to maintain the connection. Not a recommendation but an example of a BBUU: https://www.amazon.co.uk/Yuuki-Power-Router-Battery-10400mAh-Black/dp/B0FCV2Q8TB/ref=sr_1_8_sspa?crid=39ZK5UK5XEQCX&dib=eyJ2IjoiMSJ9.LAkln2F3TdJkzpDsZ4PM3IIbVgJvlOWxpV-dmD__mBqveHJzx1LCNHwlrxp3R3Ohkw93jhjNLlzCk5alZqNG4uQ7uU-G9fu9OMBplnc6pQPZVcn2cbq-N0K-4_Me0Jv8flBwB-R_7FcIEWtI0bB5iIJbQmBaXgDuO6Rw9hsAcox8vZJ5lSBfNVT_3HRfS3maRqIzkja9M0IOsVpbqIkOLUHSR4-XqmxGyCVQDtNmklA.TDLYNvEFwUuA-UqS7LGkvA9I7Fc87PZlC_82AhuLBFg&dib_tag=se&keywords=battery%2Bback%2Bup%2Bfor%2Brouter&qid=1760532347&sprefix=battery%2Bback%2Bup%2Bfor%2Brouter%2Caps%2C105&sr=8-8-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&th=1

Another example, : https://www.amazon.co.uk/APC-Back-UPS-Connect-Lithium-Ion-Controllers-White/dp/B0CJ5D89Z9/ref=pd_rhf_se_s_ci_mcx_mr_hp_d_d_sccl_1_5/521-0173109-5920813?pd_rd_w=HHVSA&content-id=amzn1.sym.a9750e23-15f2-4034-9ecc-e6dd38907891:amzn1.symc.206c6295-3b43-4a2b-9d15-273ba17f7025&pf_rd_p=a9750e23-15f2-4034-9ecc-e6dd38907891&pf_rd_r=VRHRTVKRD3CK76FK98XZ&pd_rd_wg=48Vy3&pd_rd_r=caa1ce46-96b3-4648-85e1-b94c8abdbef3&pd_rd_i=B0CJ5D89Z9&psc=1

2. Computer 240V UPSs

What is the difference to using a 240Vac UPS you may consider? Simplistically, the UPS is plugged into the mains, the mains is used to charge a low voltage battery. A built-in inverter then transforms the low voltage battery to 240V RMS 50Hz into which you connect your standard router power plug. So, during a power cut the UPS battery has to convert the low voltage dc battery to 240V ac in order for the router power supply to convert is back to 12Vdc. This all takes power, which has to be supplied by the UPS battery, hence shortening the potential run time.

In addition, the router and any other power supply these days will invariably use switch mode technology. These present a low power factor load on the inverter. Without getting into deeper geekish explanations, this results in significant additional load on the UPS battery than the simple router rated quoted wattage, with excess power having to be dissipated in the inverter.

A low voltage BBUU has the simple and very efficient task of converting the low voltage dc battery voltage to, for a Plusnet Hub, 12V dc. Hence much greater hold up time for a specific battery capacity.

Other Potential UPS Disadvantages.

A Google search for computer back up UPS will bring up many alternatives with impressive output claims such as 600kVA. The information that is missing is the battery capacity. Many of these are designed to simply give time to shut down a computer in an orderly manner, which can be less than a minute. As an example, if a 600VA UPS only has battery capacity to maintain 600VA for a minute, then all that is needed is a 10 Whr capacity battery. So, if this is used to power a 10W router, the maximum support time will be no more than an hour tops. There is another factor to also consider, some of these, especially the higher-powered ones, have, if you delve into the specifications, a minimum load requirement, needed to keep the Inverter under control, this might or might not be less than the load presented by a router.

3. An Alternative Option

Another option is to forget about a UPS designed to support a computer, but look to the leisure industry. There are some very interesting portably Inverters designed for outside living, such as camping. I have an Antek 521 https://www.amazon.co.uk/Anker-Portable-Station-Generator-Outdoor/dp/B09Q5DJV71?th=1. I have one, this will keep a 10W (unknown VA but considerably higher load as its feeding two switched mode power supplies working for just under 10 hours.

I have the option to use the 12V output for even greater hold up time. This is not continually in circuit so that in the event of a power cut I have to swap the mains plug over. On the other hand, I can also use it to keep a couple of lights on and forget my data connection for an evening,