UKC

In the context of severe flood warnings and a bad, v unsettled long-range forecast (combined with an exceptionally incompetent government) that could lead to serious power cuts, has anyone got a recommendation for a good value portable generator/emergency power supply? I want to be able to re-charge my laptop from it if there are prolonged power cuts so that I can keep on with my writing work. I've done quite a lot of Googling, and the better ones have the facility to be charged up in different ways, including from solar panels. The sort of thing I have in mind is this:

https://www.amazon.co.uk/ALLPOWERS-Portable-Generator-Emergency-Technology/...

... but I know very little about these things/have no expert knowledge whatever.

Small generators are a pain.  Once they’re filled with oil and fuel and run, they get cruddy if you don’t run them up periodically or strip and clean them.

Cheapest option is a laptop charger that runs from your car’s cigar lighter.

Solar is bugger all use around winter storms due to lack of decent light.

If your laptop can take power in over USB C, a suitable battery pack (including some car jump starters) is about £100 and is small enough to be taken to a local pub for recharging...

Thanks for your answer, but I'm not understanding you. The one I gave a link to is not a generator run by any kind of engine requiring fuel. It's all done with lithium batteries. And, if you look at its specification, you can see that it can be charged from a car cigarette lighter. Or from the mains. Or from a solar panel. 

I assumed you meant either a combustion based generator or a portable battery supply.

The box you linked costs several hundred quid.  You may be able to get a cable to charge your laptop directly from the cigar lighter socket for a tenner and save yourself several hundred quid.

If this is for low probability use and just for a laptop, and you have a car, solar is a lot of hassle.  Even a small flexible panel takes space to store and it’ll be useless in high winds or winter light.

A portable battery power supply only makes sense if you want to power lots of other things too.  You can get a leisure battery and a decent 12V to mains inverter for much less than the item you linked, but the box is much easier to use 

In reply to NERD:

My understanding is that batteries can damage your computer, and an extra gizmo is needed to make it completely safe. Which is all included in this one.

What I have in mind is something for quite an extreme emergency i.e a power cut lasting many hours. That's the sole purpose for it. 

In reply to NERD:

The last photo on that link horrified me.  A 240v AC socket with three flush, exposed copper terminals.  Even if there is some internal logic to detect a closed circuit and then only apply power there’s no way in the world that’s even remotely safe.  It’s a child killer that has never seen BS1363.  The vendor pulls this “we’re just a marketplace we’re not liable” crap.  

Oddly the first photo shows a face plate over the socket but bare copper is still visible where it shouldn’t be, and there are no shutters.  Worse still - at least 31 people bought it and left reviews and are walking round with portable child killers.

In reply to NERD:

PS. What you're suggesting looks very good (with all the inbuilt safety devices.) But it wouldn't last nearly as long. We're talking about £100 for about 6 hours, and £239 for many times that. But this is exactly the question I need to have answered, so thanks.

PS2. I told you at the top of the thread that I know NOTHING about it ... except what I've learned in the last hour or so by Googling

One snag is I don't have a car ...

Surely there are caravan/campervan owners here who sometimes camp in wild places for several days away from any campsite with electric hookups, who must know about these things?

Batteries it is then.  The key thing is if you need one with a mains converter/output or not.  That depends on how your laptop charges.  If it charges by USB-C you don’t need the mains output, just a suitable battery.  If it has a specific charge brick with its own specialist connector you probably want a battery with mains output.

Well, it's a very standard Macbook Pro dating from c 3 ½ years ago, and I think the charger/external power supply is USB-C ... I'll have to look that up.

Looked it up. The charger/power lead goes into a thing called the 'Magsafe 2' power point. It also has two 'USB 3' ports.

In reply to NERD:

Thanks for your sage advice, 'NERD'. At a scientific level I always find any signs of brain activity interesting. On the other hand, the irony of your username is huge, and I realise I was a bit of an idiot ever to have taken you seriously. More fool me. Byee.

Probably better looking at what boaters have. They are moor (!) Used to sitting in one place for long periods and often have sophisticated wind/solar combinations

In reply to NERD:

I've got a similar size battery from a well known outdoor power brand. It's great, ideal for camping/#vanlife and will charge (slowly) off a 12V supply or via the same-brand solar panel (the latter often surprisingly successfully). 

However, to get to my actual point - it only charges my MacBook (15", 2019) to about 95%. The Mac has a 84 wH battery - which translates to 9/10 hours of use, so 1-1.5 days of work. Not ideal for sustained power cuts! Depends of course what the OP has in mind.

A car battery or anything 12v, a bike battery is easier to move about and a 12/240v invertor would be a basic solution. Many come with normal plug sockets and usb charging ports. 

There are multitude of charging options to consider from normal car chargers to solar. 

first sensible suggestion.   Simplest, cheapest and probably the most effective. A Leisure battery with a suitable mains charger would do, but any car battery would give a lot of ampere hours and 1000 times as many mAH!

Then some kind of 12v car adaptor for charging the portable device/laptop

Not sure if it would be a bit of a pain (i.e. it’s a bit messy) but a Decent Leisure battery with a small inverter would work. You would probably want to make a self contained box for it as you’d need to do some wiring etc. 

Could be charged via mains with the right charger. Though you would probably want to cycle it occasionally to keep it healthy. 

We live on a boat and therefore rely on these all the time. Using 1 battery would be fine for charging a laptop. We’ve got 5 but heat water, use lighting, big speakers, fridge, etc. 

Boating forums (+ probably van conversion websites) would offer plenty of advice/options. Happy to help too if needed. 

I don't think you'd even need a 12v-230v invertor. All your laptop charger would do is bring the 230v back to 5v (assuming it is charging at USB standard) and you'll have wasted loads of power in the conversions. 

I think 12v battery - cigarette socket with croc clips - car USB adaptor - charging cable will do the job, won't it? For more capacity, get more or larger batteries.

Surely during a power cut, keeping the boiler and fridge running would be better than making sure the laptop has enough charge ??

Well, that's a separate, serious problem (requiring solar panels linked up to some kind of generator/power supply). I'm talking about the specific problem of being a non-fiction writer working to a deadline, requiring use of my laptop to access all the research files involved for each chapter. The general advice from many above is simply to use a 12V leisure battery, such as used by boating people, and not bother about any kind of generator.

https://www.amazon.co.uk/dp/B00T7BYPDG/ref=psdc_430442031_t3_B002RL0CKI

I'd agree with this. If the power is out for any length of time during the winter, you'd be cold and sat in the dark (or with candles). Your creative juices would dry up quickly, once you start shivering and having to eat cold beans. You'd also need to tether to your phone in order to gain internet access, as your router would be down.

Perhaps you should consider a more holistic approach, if you've not already done so. Will you have heat and light? Can you feed yourself and make a hot meal? How big a power cut do you want to protect against (hours or days), would other services be affected e.g. flooding cutting off roads/gas/water? I'd say the ability to use your laptop, comes way down Maslow's list of needs, in an emergency.

You could go the full prepper route and keep your house stocked with food, have alternative means of heating, bottled water supplies etc. In some situations, it might just be easier and cheaper to get a train or taxi to a hotel X miles away, that is not affected.

I think you'll be surprised how efficient they are now. I have an 80W panel on my boat. When i installed it my 110Ah 12V battery was showing 12.4V. After less than an hour in really overcast conditions the voltage had risen to 12.9V. 

That was in winter, just a few weeks ago. I'm quite excited by how much power i'll be able to use in the summer!

Thank you. Very helpful.

I have gas fires that can be used in a power cut in both my main downstairs rooms.

Of note in that, though, is that when the 2015 floods knocked out Lancaster's main substation (which some fool thought would be best located down by the river) it also knocked out the rail service (because the station had no power) and mobile phone service once the backup batteries on the cell towers had run down - so not only did you have no electricity but you also couldn't travel out unless you had a car (the buses were also very restricted, I seem to recall they turned round at the roundabout just before the city centre and the north of the river was cut off other than going via the M6) and couldn't phone anyone or use the Internet to check what was going on, so even booking a hotel as suggested would have been hard.

I recall it took well over a week to get it back, though its defences have now been shored up so it shouldn't happen again.

When I'm camping or needing an emergency light or just discharging 24v Nicad batteries that need to be recharged I use the LED GU5.3  type lamps as they are quite happy to run between about 10 and 27 volts and provide quite a lot of light for only about 5W consumption (equivalent to about 35W incandescent).  You'd need to rig up a connection with wire but they would give you a lot of light for a long time to go with your laptop and gas heater.   You'd want to fuse the wire from the battery as shorting a supply from a leisure or car battery (or even 5ampere hour Nicads) can be spectacularly dangerous.

One of my 24v radio batteries will run one of those GU5.3s for several evenings and the pins of the lamp fit exactly into the charging socket on the battery making them great for use as an impromptu lamp or even a powerful torch

Not exactly what you're looking for but I use an inverter plugged in to a car jump starter to run my router, screen and notebook on the rare occasions that mains power fails.  Sufficient for 4 to 5 hours, long enough to get organised for a possible longer outage and do anything urgent.  I had both bits of kit anyway (and both are multi-purpose) but you could buy for less than £100.

Do you have a bicycle? Get one of these and keep fit while you write

https://www.amazon.com/Pedal-Power-Bicycle-Generator-Emergency/dp/B003GJL6G...

At least it is actually a generator, unlike the so-called generator in your first link, which is just a battery in a box with a charger an inverter.

As others have said, if it's to run a laptop for a few days and doesn't need to be portable then a leisure battery with a suitable charger would be your best bet. A specific car charger for your laptop is the most efficient, but a cheap inverter and your regular mains charger would do. I use this setup in my campervan.

We live out in the sticks on the end of a long power spur. I used to have a generator, but they’re a bit unreliable if you’re not using them frequently.

My solution is a good quality inverter connected to the battery in my van. I switch off the main fuse board to disconnect from the grid, then supply the house from the van via a socket in the garage. Plenty of power to keep some lights, central heating, laptops and WiFi running. 

Thanks for your answer. But there are two main problems for me with this: 1. As I said earlier, I don't have a car or van (some wally even sneered at me for not having one, when I drove about ½ million miles over 40 years but can no longer do so because of an eye injury) 2. Are you really saying you run all that off your van's battery without turning on your engine? I would have thought it would run you battery down very fast indeed.

I hope your fuse box disconnects the neutral as well as the live.  Even then I’m going to pretend I didn’t read your post and hope that you lock the garage when the Plug Of Death is connected.

Cheap inverters aren’t great at isolating the DC from a floating AC potential so the bad choices are to either not neutral/earth bond the inverter and so to have no functioning RCD protection or to have the van floating with an AC potential with respect to ground.

If you get a chance have a proper break-before-make transfer switch fitted with a plug inlet not a socket inlet.  Difficult without running a second cable to the garage and barely worth it for occasional outages.

Still, 30 years later I have vivid memories of why I hate power back fed by a plug...

I second this. Back feeding a mains installation is potentially dangerous (and illegal) if not done properly and in some not immediately obvious ways. It can also endanger the dno engineers or technicians trying to make repairs. Not to be dabbled with unless you know what you are doing . 

Are there many single pole switches in fuse boards, even very old stuff is usually two pole switching?

Hi there, I wasn’t posting a tutorial or instructions, just an outline. So, yes to all the above, the garage came with a second dedicated feed for a generator with break before make which supplies a dedicated isolated circuit in the house. I also isolate the incoming mains via two pole switch as belt and braces. Locked garage 100 m up a drive.

The house came with this as was on a very long above ground spur which was always coming down. Supply is underground now, and no power outs since then. V expensive inverter which I checked in the lab for isolation and mutual coupling. When we bought the house it was all rewired and/or certified by electrical contractor

Good good.  I thought you’d have done a safe job but I’ve seen some horrifying lash ups...

In reply to NERD:

Well that looks very interesting. If I owned a detached house in the country I'd certainly consider it. Unfortunately, the 'box' is that I live in a terraced cottage in a conservation area and I'm 100% certain I wouldn't get planning permission for it.

temporary things are not a usually considered under planing.

Which is what you're interested in isn't it.  

I've had a few of the cheaper units on the bench and its like having a waveform generator. Even at relatively low loads, they tend to saturate to six-step waveform, and wipe everything in the lab out with EMC

I got a cheap 1 kW inverter from a well known marketplace.  Just looking at the row of 6 paralleled blade fuses on the back tells a story about the mindset of its designers....  I now use a Victron device instead; the multiplus-II I have can run a microgrid and keep the AC connected solar panels online in an outage which is dead handy.

Leisure battery, trickle charger and an inverter or 12Vdc charger for your laptop. Stick it all under your desk as a footrest so you actually get some value from it.

jk

Thanks.