Power bank instead of stupid old extension cord

March 11, 2023 10:11 AM

I'm looking for a rechargeable power pack of some kind that I can use for a lamp, phone charger, and alarm clock next to my bed.

To make a long story short, the outlets in our bedroom don't make any sense. What we're doing now is running an extension cord across a high traffic area. I hate it. We can't move outlets or add outlets because we rent (and apparently there are some structural reasons why the bedroom is how it is.)

I'm thinking, feed two birds with one scone: get an emergency power bank for power outages that I can also use all the time for my bedside outlet. Is there such a thing, where do I get it, and which is the best one?

posted by blnkfrnk to Shopping (16 answers total)

Portable Power Station
posted by oceano at 10:24 AM on March 11, 2023

We own two portable power stations: one is the very popular brand Jackery, the other is a shockingly solid Chinese-random-name AEIUSNY that offers more amp hours per dollar than the Jackery and other as-seen-on-Youtube options.

I honestly think they're all mostly the same guts, but I will recommend you specifically get one that lists a "pure sine wave inverter" as the alternative can be bad for computers and computerized electronics.

Anyway, they're great, and if you ever get the itch to play around with solar you can pick up a 100w panel in stationary or portable formats. I own both of these but I recommend a portable unless you're absolutely sure you have a place you want to mount one permanently - good portables have their own built-in solar controller with USBs in, so in a pinch you can just open that baby up and charge your phone or whatever straight off it. On camping trips with open treeless space on a sunny day, the panel can charge a half-drained power station in 5-6 hours, and directly charge a phone in 2ish.
posted by Lyn Never at 10:53 AM on March 11, 2023 [2 favorites]

A few things to consider:

1) The amount you pay will pretty directly scale with how large the battery is and how long it lasts between recharges. The capacity is usually measured in Wh (Watt-hours). A single phone charge from empty might use ~20Wh. A lamp with an LED bulb on for an hour will use maybe 10Wh (the bulb uses 5-6W, but there is inefficiency in the power station's inverter making AC voltage). An AC-powered alarm clock might use around 150Wh per day (again considering the inverter inefficiency too). So very very roughly, you might use 200Wh per day. And also very very roughly, power stations cost on the order of 50 cents to $1 per Wh of capacity -- $100 to $200 per day of charge for your usage.

2) Power stations come with USB ports as well as normal wall-style AC outlets. The inverter that creates the AC voltage introduces inefficiency, so you want to plug as much as you can into the USB ports. For example, you should charge your phone by plugging it into a USB port on the power station rather than plugging a phone charger into the AC outlet on the power station. You might also look for lamps and clocks that can be powered from a USB port -- in my quick searching for those, any I find have rechargeable batteries themselves (e.g., lamps, a clock). Getting a USB-powered or rechargeable clock will have the biggest impact on reducing your energy usage and how often you have to charge the power station.
posted by whatnotever at 11:03 AM on March 11, 2023 [6 favorites]

Have you thought about just buy a VERY long extension cord and run it along the perimeter of the room... Or route it OVER the door frame itself, if that's what's stopping you?

You can get 15 ft, 25ft, even 100-120 ft extension cords on Amazon. Even Amazon itself has an AmazonBasics 100 ft 3 prong cord for $25.
posted by kschang at 11:32 AM on March 11, 2023 [1 favorite]

I have a clock and lamp that both run from USB power. Any USB power bank would work - and you can use a hub to add jacks. The lamp will only use power while it's on (get one with a clicky hardware switch that won't use power otherwise).

This is a camping lamp that has a phone charger plug. I think it's the one I have, but I don't use it by the bed currently.

This is probably the clock I use - it has a USB plug for charging a phone - but it's clumsy and falls over a lot (however: it also allows you to turn off the glowing numbers, to achieve total darkness, and it uses a sunrise-like light to wake you up).

In theory, you could chain things: phone power bank -> lamp -> clock -> phone.

Bonus: it's fairly easy to find a solar system that will charge a USB power bank.
posted by amtho at 12:18 PM on March 11, 2023

Response by poster: Yes, I have thought about a long extension cord. The outlet is a 2-prong outlet. I can't find an extension cord that is long enough with a 2-prong end and an end with 3+ outlets in a quality or from a source I trust. I really don't want to chain an outlet adapter to an extension cord to a power strip.

Solar is intriguing but for site-specific reasons (poor sunlight orientation and poor window placement, long, dark, below-zero Alaska winters, lot of impulsive theft in neighborhood) we can't have a solar charger live outside and we don't have a place for it inside.
posted by blnkfrnk at 1:00 PM on March 11, 2023

Depending on the ground available, it may be as simple as adding a 3-prong adapter to the outlet, and make sure you wire the ground properly to the central mounting screw, and make sure the outlet frame itself is grounded.
posted by kschang at 1:28 PM on March 11, 2023

If you're only plugging in devices that don't have a 3 prong plug, there's not really an issue with using a quality adapter if you can't get an appropriate three prong cord and you take care to ensure that nobody plugs in high power devices or devices that require a ground connection. You just need to make sure all connections are solid, nothing loosey goosey.
posted by wierdo at 1:36 PM on March 11, 2023

Response by poster: Great! I still want a power bank instead. Any additional advice on power banks?
posted by blnkfrnk at 2:16 PM on March 11, 2023 [3 favorites]

If you like a quiet bedroom an AC power pack may not be for you. I haven't yet met one of these devices that doesn't emit a razzing hum while it's generating AC from battery power. That doesn't mean a silent one doesn't exist, but it does mean you'll need to select even more carefully.

If, instead, you choose to go with USB power pack, choosing to replace your plug-in lamp with a camping light and your alarm clock with either a battery-operated one, or one that plugs into USB, you should have no problem finding a silent one.
posted by seanmpuckett at 2:26 PM on March 11, 2023 [2 favorites]

Adding in to the previous comment, there are also rechargeable USB home lamps that are surprisingly nice (and useful in an outage).

I couldn't tell from the question if you were looking for the smaller, portable kind of external battery/power bank or the bigger and longer-lasting ones. For the former (and possibly the latter? Idk) Anker had a good reputation last I checked. You would still need to remember to charge them frequently in this scenario, right?

About extension cords - it's possible to find very long USB cables, so if you found some that were long enough for your room you might be able to get by just with that (assuming USB-powered lamps).
posted by trig at 12:27 AM on March 12, 2023

I really don't want to chain an outlet adapter to an extension cord to a power strip.

If you're powering only a bedside lamp, a phone charger and an alarm clock you won't be drawing more than one amp through such a combo, and probably just half that. Even the most weedy adapter and extension cord will laugh at such a light load.

Another matter: does your alarm clock lose its settings when you unplug it? If that's the case you will need to be able to recharge the powerbank in-situ, which would require getting out an extension cord. Otherwise, unplugging the powerbank to recharge it elsewhere, and then re-entering the alarm clock settings will get more than annoying very, very fast.
posted by Stoneshop at 5:22 AM on March 12, 2023

trig: About extension cords - it's possible to find very long USB cables, so if you found some that were long enough for your room you might be able to get by just with that (assuming USB-powered lamps).

Maximum USB cable length is 5m/15' (though I don't doubt you can find longer ones on AliExpress, and of course no-one can stop you from daisychaining them), but running the power for any of these three devices through one is bound to disappoint, especially for the lamp, and the phone being charged. Quality cable, 5m long, voltage going in: 5.06V, current: 150mA, voltage coming out: 4.7V. The phone and the lamp will draw more than that.
posted by Stoneshop at 7:01 AM on March 12, 2023

Both of our battery banks have small fans that run periodically, but this is easily mitigated by putting it a few feet away just as an electrical socket would be. Also the use of any fan slightly larger will drown it out, as will the various white noise generators often used for sleep.

I can't even hear it under the foot of my cot in the creepy silence of camping (plus a light gloss of tinnitus).
posted by Lyn Never at 11:13 AM on March 12, 2023

It's good to stick to known brands for stuff like this, since the consequences of a bad battery can be flames. Anker is good, but in this case the one I was going to recommend tends to leak power while not in use so this Jackery one seems like a good option. There's a step up in capacity here for a similar jump in price. Goal Zero is apparently also good but a bit more of a premium.

I would only say, do a basic calculation of how much power you'll draw and how often you want to recharge the thing, and whether you want to move it or run a cord over, etc. It would be annoying to unplug your alarm clock or carry it around so it doesn't reset, right?

But if you consider charging your phone as being a couple watt-hours per day, an LED-based lamp the same, and a low-draw alarm clock, the 300 watt hour thing could probably go a month at a time without a charge.
posted by BlackLeotardFront at 2:03 PM on March 12, 2023 [1 favorite]

Another option, besides the portable power stations mentioned above, is something like an uninterruptable power supply (UPS). These are designed to be continuously plugged into the wall, in between the power mains and something like a desktop computer, to power the computer for a few minutes during a power outage (to bridge a power outage of a few seconds or a couple of minutes, or allow graceful shutdown of the computer in case of a longer power outage).

Here is one I have. Some other options from Amazon.

These are not purpose designed to be a power station, but for a few low power items it might work fine. They are pretty standardized, mass produced, off-the-shelf systems so they might be somewhat cheaper than power stations as mentioned above.

Do note they are likely to have less storage than the power stations. The one I linked above only has about a 110 amp-hour battery, which is around 1/3 of the capacity of (for example) this or this.

The batteries are replaceable, which I like. I replaced the battery in mine after about 7 years continuous use - HOWEVER that is continuous use as a computer backup, not draining it down every night. Daily usage/drainage will definitely wear it out much faster. The battery is a lead-acid type, which likes to be continually kept topped-up and not drained deeply often - whereas the power stations are more likely to have something like lithium batteries, which hold up better under deeper charge/discharge cycles.
posted by flug at 2:27 AM on March 13, 2023