This Quick Hack Will Keep You Online During Your Next Power Outage

The modern human’s worst nightmare: a power outage. Left without cat memes, Netflix, and — of course — Hackaday, there’s little to do except participate in the temporary anarchy that occurs when left without internet access. Lamenting over expensive and bulky uninterruptible power supplies, Youtube user [Gadget Addict] hacked together a UPS power bank that might just stave off the collapse of order in your household.

This simple and functional hack really amounts to snipping the end off of a USB  power cable. The cable is then attached to a screw terminal to barrel connector adapter and plugged it into a pass-through power USB power bank. No, really — that’s all there is to it. [Gadget Addict] notes that while most modems and routers are designed to run off a 12V power supply, they still operate at 5V. He goes on to connect several router and router/modem combination units to the power bank. In each case the system appears to boot up and perform normally.

The particular UPS unit [Gadget Addict] was  using has a lead acid battery that was prone to failure on an almost annual basis — which defeats the purpose of a backup power supply for even a non-critical system. This quick hack could be the ounce of prevention that offsets the potentially hours of internet-less boredom that strikes with your next power outage. An accompanying solar-powered 3D printer should also keep you plenty occupied.

[Thanks for the submission, Gadget Addict!]

56 thoughts on “This Quick Hack Will Keep You Online During Your Next Power Outage

    1. I wondered the same thing, but at 1:50 in the video he mentions you need a power bank that supports “pass through power” or “pass through charging”, which I didn’t know was a thing.

    2. I searched ebay but I can’t seem to find the right keywords. I have heaps of cells and there are powerbank enclosure kits but they don’t say if they have pass through charging.

      Any tips would be greatly appreciated! Thanks. I even thought of those powerbanks for jump starting cars.

    1. See if your cable company sells VoIP and security system functionality in your area. If they do, then it’s highly likely the entire chain has backup power.

      As for the problem with UPS’s killing batteries: APC intentionally sets the float voltage too high on most of their UPS’s. Measure the battery temperature with a thermometer, look up the proper recommended float voltage for that temperature (most manufacturers publish datasheets), then check the voltage with a high quality voltmeter. You can even lower the voltage slightly if you want to trade longevity for capacity; in most cases, we care about riding out a temporary blip or giving enough time to shut down cleanly.

      …and others. On USB models, you have to go in with a TTL cable (I’m sure HaD readers can do better at identifying the correct pinout):

      1. Ah-ha, WNBAH = Would Not Be A Hack
        OTOH, I haven’t seen any USB-to-barrel-connector cables with an integrated boost converter for an application like this. That might make an interesting project though.

    1. Ha ha – burnt mine doing exactly that. Replacement router works fine though, with manual change-over for power outages. Building a $1 changeover circuit with some low-drop Sckottky diodes so the battery can be connected all the time, and no router reboot required

  1. Just a note. Some devices can appear to go on with 5 volts, but won’t function all the way without 12 volts. Cable modems are especially prone to this (i.e. you get the switch functionality but the interface to the coax won’t come up).

      1. I used, some years ago, to power a router with 7.5V when the original power supply was a 12V one. Looking at the board, there was a linear regulator just after the barrel socket, outputing 5V to the rest of the board.

  2. Wouldn’t help out much in my case. If the power goes out at my house, there’s a good chance it has also gone out at my ISP. I don’t know if they care enough to have a UPS or a generator to keep things going.

  3. using a power bank is a lot more efficient than a ups since you are starting with 5 volts

    a ups has to step up the 12 volts of the battery to 110 volts ac witch is very inefficient because of the volt amp trade off so your ups can be drawing several dozen amps from it’s battery and usually there is a 12 volt 7 amp hour battery

    sometimes there are 2 12 volt batteries for the bigger ups’s and the really big ones for servers would use 4 12 volt batteries at 48 volts.

    smaller ups’s use maybe 6 volt

    so a normal ups will not run very long maybe 5 to 10 minutes and are intended to all you to shut down the stuff safely.

    connecting a 12 volt car battery can give longer run time but at the cost of burning up the ups inverter as they are not designed to run for hours.

    there is a little loss in the getting 5 volts from 3 to 4 volt lithium cells but it is way more efficient than a normal ups.

    and parallelling the cells would give longer run time.

    some times you can over volt a little if there is a regulator to step it down

  4. I would relish a power cut as an opportunity to get the candles and board games out but they are very rare here.
    I have experienced only one in at least 15 years. Calling the power company the lady handler told me I must have been mistaken and to call an electrician to check my premises. I explained the street lights were out and she suggested they were fed from my property so I didn’t bother arguing. I was alone and didn’t have any games or candles, I did have a charged laptop and tethered data but I just went for a sleep instead. Sure enough by 3am the road was closed, cable was exhumed replaced and jointed. Power restored in a few hours but the hole was left for a few weeks before the road was repaired.

    1. I wouldn’t say that but I agree that the title of this article is really terrible.
      Would have been fine with “Power a router with a powerbank”. But then I wouldn’t even bother reading it.

    2. I have the feeling it was not like this before they sold their soul to Supplyshame.
      I´d prefer fewer articles than this regular trash (also almost always from the same authors).
      They´re paid by article. The more they feed the tube, the more money they get. What can go wrong ?

  5. My internet used to be copper all the way to the home office so it stayed up during power outages and I did something similar, only 1.5mbps but it worked. Now that my area has fiber I get 25mbps but the fiber box out at the street is mains powered with no backup so when power goes out to it no internet.

    1. I used to have a modem (from my ISP) that had in the brochure a mention that it could have a internal battery and keep running when power was down, but my ISP decided to get the cheaper version.
      Mind you the power is almost never down here. But it’s interesting that the modems that came after that never had that feature, not even as an option for the ISP, whereas now all modems and subscriptions also come with a VOIP phone line, plus everybody has devices that use WiFi and are battery powered, so in this day it would make even more sense if the thing kept working.
      But meh, we can manage a few hours without internet I suppose.

  6. Surely the router has voltage regulators inside? So it will actually be drawing more amps in order to provide enough amps when the router has regulated it to 12v? If that is the case then is the USB cable not at risk of being overloaded?

  7. Or you could just turn on your phone’s hotspot….and power that with the power bank. Linking your home PC to your phone is quite easy and there are several methods. Plus it is a lot more likely for the cell towers to still be up than for your local gateway.

      1. My Note 2 has a stock ROM modified to allow tethering but AT&T gets a bit unhappy when they find you tethering without a tethering plan despite my having a grandfathered unlimited plan.

        Great way to get hit with fees.

        1. I have a Moto G on VZW and they balk at tethering too. But, I’ve found that they really can’t bitch much about it since I also am on a pre-paid plan. Therefore, tethering is the fall back and gets limited use to emails. They’ve tried pushing and promoting me to an “unlimited”, 2-yr contract a few times, but when I ask about tethering allowances, they clam up.
          I only really ever have used it for work purposes, and am unemployed at the moment, so if the need arises, I’ll make a payment and have service for 31 days.

  8. Surely if it was that important you would have installed a backup generator, that way you wouldn’t need to look for various adapted usb leads in the dark.
    and as anybodysguess says, whatvif you’re on the same phase as the roadside cabinet or in our case the telephone exchange, although like us they have a generator.

  9. this is really iffy.
    I tried this with a stick PC and a famous chinese power bank. The power bank supports “pass through charging” mains -> adapter -> power bank -> plug PC. all was working fine until the power outage and the plug pc went kaput. The power bank was not fast enough to switch on the boost converter and the PC had shutdown.

    make sure you really test the setup with your equipment before deployment :)

      1. Damn, that just made me shudder that that came from a University. Radioactive field?? Short range radiation? Obviously talking about Alpha and Beta particle emission, which can’t even claim to be electromagnetic like Gamma, and even if it WAS gamma an EM wave is not a field.

        I know they have to dumb it down for the hacks, but may as well use pixies and goblins for all the insults to science in there.

  10. The hardest to find item was completely glossed over in the video – I have at least a dozen USB battery packs and none of them have this “pass through power”. I’ve been searching for such a device as a UPS for Rasberry Pis / Arduino / ESP projects.

    1. Agreed. Also the rate of charge has to be greater than the consumption of the powered equipment. My modem/router is 12V 2A and I also have a wireless phone that I would want to attach so that I can make calls (VIOP) when the power goes out.

      Now I am thinking it would be better to just use a SLA battery and charge at 13.8 Volts and hope the equipment is happy with the slight over voltage (1.8V) or make a custom LDO regulator that will always transfer lower voltages when the battery voltage drops.

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