London has no free public charging network. What it does have is a plug in almost every hotel room, power sockets at every seat on the airport express trains, USB ports on a minority of red buses, and rental power banks in pubs and shopping centres that cost around £2 for half an hour and are capped at £12 a day.
For most visitors the phone is the ticket, the map and the wallet all at once, which makes a flat battery more than an inconvenience. If your contactless card is inside your phone and the phone dies at Green Park, you are walking.
This page is about where the electricity actually is: which trains have sockets, what the rental batteries charge, and which public buildings will let you plug in for an hour without buying anything. If you are still packing, our guide to British plugs, adaptors and voltage covers the hardware you need before you arrive.
Charging in London at a glance
- Tube, tram and DLR
- No passenger power sockets. Plan around them, not on them
- Heathrow Express
- At-seat power sockets in both classes, plus free wi-fi
- Red buses
- USB ports on newer vehicles only; not guaranteed on any route
- Rental power bank
- ChargedUp: first 5 minutes free, then about £2 per 30 minutes, capped at roughly £12 a day (prices vary by station)
- Keep it too long
- ChargedUp charges about £25 after three days and the battery is yours
- Free sockets, no purchase
- British Library public study desks, borough libraries, some station waiting rooms
- Flying home
- Power banks go in the cabin, never in the hold; two per person
Why a London day flattens a battery faster than a day at home
Three things run in the background here that do not run at home. The first is the map: turn-by-turn walking directions with the screen on are the single biggest drain, and most visitors use them for hours.
The second is signal-hunting. Coverage underground is still partial, so between tunnels your phone repeatedly climbs back onto the network at full transmit power. Our page on getting a British number or an eSIM sets out where the signal exists underground and where it does not.
The third is that you are outside in daylight, so the screen is at maximum brightness all day. Add the tap-in and tap-out of contactless travel and a camera in constant use, and a phone that lasts from breakfast to bedtime at home will be asking for a socket by four o'clock.
A dead phone is treated as a missing touch-out. If your battery fails between tapping in and tapping out, the system records an incomplete journey and charges a maximum fare. Our page on what happens if you forget to touch out explains how to get it refunded, but a physical card in your pocket avoids the whole problem.
Which trains have sockets, and which do not
The rule of thumb is simple: the further the train goes, the more likely it is to have power. Nothing on the Underground has a passenger socket, and neither does the DLR or the tram.
Heathrow Express is the reliable one in central London. Its own description of the on-board experience lists at-seat power sockets and free wi-fi across the train, with plug sockets at every seat in the PREMIER+ carriages. It is a fifteen-minute run from Paddington, so it is not a charging strategy, but it is useful if you arrive with an empty phone and a hotel check-in ahead of you. Our comparison of the Heathrow Express and the Elizabeth line covers the price difference.
Long-distance trains out of Euston, King's Cross, Paddington and St Pancras generally have sockets at or under the seats, and usually wi-fi as well, though the operators do not all fit the same equipment and replacement trains sometimes have neither. If a charge matters on a day out of the city, check the operator's own page for that service when you book; our guide to buying UK train tickets explains who runs what.
The bus question, and why the answer is "sometimes"
Some red buses have USB charging points in the seat backs and some do not, and you cannot tell from the route number. Transport for London answered this directly in a freedom-of-information response published in February 2021: more than 520 vehicles were fitted with USB ports at that point, and new vehicles entering service on the red bus network are required to have them.
The key sentence in that reply is that TfL does not require USB ports on particular routes, only on new vehicles as they join the fleet. Buses move around for maintenance and cover, so a route that had them yesterday may not today. Treat a working USB port on a bus as a small piece of luck rather than a plan, and read our guide to London buses and night buses for what the network does well.
Sightseeing buses are a separate question and the operators change specifications often; do not assume the open-top deck has power. Our assessment of hop-on hop-off bus tours looks at whether the ticket is worth it at all.
Renting a power bank: the real numbers
Rental batteries have spread through London pubs, bars, shopping centres and offices over the past few years. You tap a card on the station, a battery pops out, you use it and return it to any station on the network, in a different building if you like.
ChargedUp is the network most visitors will meet. Its published pricing is the first five minutes free, then £2 per 30 minutes, capped at £12 per day, with the batteries rated at 6,000 mAh — enough to fill most phones once. Keep one for more than three days and you are charged £25 and it becomes yours. The company notes that prices vary by location and that the actual price is shown on the station when you rent.
That is the number worth doing arithmetic on. Two half-hour top-ups across a day is about £4, which is fine. Forgetting the battery in your bag until the following evening is closer to the daily cap, and forgetting it for a weekend costs more than a decent battery in a shop.
| How you charge | Typical cost | Best for |
|---|---|---|
| Rental power bank, one 30-minute top-up | About £2 | An emergency on the way to dinner |
| Rental power bank, held all day | Up to about £12 | Almost nobody |
| Own power bank bought in London | Usually £15–£35 on the high street | Any trip longer than two days |
| Sitting down near a socket | Free, plus a coffee | Anyone with an hour to spare |
Prices for rental networks change and differ between venues, so check the figure on the unit before you tap. For how this fits a wider daily budget, see what a day in London costs.
Buying a battery here instead
If you arrive without a power bank, they are sold in high-street pharmacies, electronics shops, department stores and most large supermarkets, and at the airports at airport prices. Two specifications matter more than the brand.
Capacity: 5,000 mAh is a single phone charge and fits in a coat pocket; 10,000 mAh is two charges and the size of a paperback. For a family, one larger battery and a short multi-port cable beats four small ones.
Charging speed in: a battery that takes six hours to refill is no use on a three-night trip, because you will be out during the day and asleep at night. Look for one that refills while you have dinner.
Sitting down next to a socket, for nothing
London is short of public sockets in the street but not short of them indoors, if you know which buildings do not mind.
The British Library at St Pancras is the best of them. Its public study desks are open to anyone with no card, no registration and no purchase, and the Library describes them as having free power and free wi-fi. Borough libraries are the same idea spread across the city: Southwark, for instance, states plainly that its libraries are free for residents and visitors alike and that every branch has desk space, computers and wi-fi. Our guide to working from a cafe or a library in London goes through the individual buildings, their opening hours and what the staff will tolerate.
Cafés are more mixed. Sockets exist in chains that want you to stay and are often deliberately absent in small places that need the table back. Ask before you crawl under a table with a plug; nobody minds being asked, and some places switch the sockets off at lunchtime. Our guide to free wi-fi in London covers the connection side of the same problem.
Large stations have some sockets in the paid waiting areas and occasionally on the concourse, but they are heavily used and often occupied. Airports are better provided: charging posts near gates are now standard, and lounges have them at every seat, which is worth knowing if you have a long layover at Heathrow.
Hotel rooms, hostels and the socket behind the headboard
British hotel rooms in older buildings can have very few sockets, and the ones that exist are often behind furniture. Newer chains fit USB ports into the bedside lamps or the socket plates; conversions of Victorian houses frequently do not. Our page on what a London hotel room is actually like sets expectations for the rest of the room.
Bathrooms are not the answer. Ordinary sockets are not permitted in British bathrooms, and the two-pin socket by the mirror is a shaver socket with very limited current; it is not for a phone or a laptop.
In a hostel dormitory the sockets near the beds are shared and in demand, and leaving a phone charging in a common area overnight is asking for it to be taken. If a hotel offers a charging locker at reception, that is a genuinely useful free extra, and rarer than it should be.
Taking a power bank home on the plane
This is the rule people get wrong, and getting it wrong at security costs time. The UK Civil Aviation Authority tells passengers to always take spare batteries, vapes, e-cigarettes and power banks with them in the cabin, never in checked luggage, and states that you can only take two power banks per person.
Two further points from the same guidance. Power banks should never be recharged on board the aircraft. And capacity matters: under 100 Wh is fine in the cabin, 100–160 Wh needs the airline's approval, and anything above 160 Wh is not allowed in passenger baggage at all. A typical 10,000 mAh travel battery is well under the first limit, but the rating is printed on the casing if you want to check.
Check your own airline as well as the CAA. Several carriers have added their own conditions on where a power bank may be stowed during the flight, and cabin crew may ask you to keep it in the seat pocket rather than the overhead locker. The airline's rules apply on top of the national ones, not instead of them.
What to do at four per cent
First, switch on the battery saver and turn the screen brightness down; between them they buy a surprising amount of time. Second, stop using live navigation and take a screenshot of the next few streets instead, which costs nothing to display.
Third, get off mobile data where you can. Station wi-fi is available at Underground stations and many others, and using it stops the phone hunting for a signal between tunnels.
Fourth, have a fallback that does not need a phone at all: a paper note of your hotel's name and street, and an Oyster card or a physical contactless card for the journey back. Emergency calls are the one exception worth remembering — on a phone with any signal at all, 999 and 112 work even without credit, as our guide to emergency numbers in London explains. And if the phone is gone rather than flat, our page on what to do if your phone or wallet is stolen takes it from there.
The apps worth having before any of this happens, including offline maps, are listed in our guide to the apps worth having in London. On a hot day, remember that phones throttle and lose charge faster in direct sun; see London in a heatwave for the rest of that problem.
Frequently asked questions
Are there charging points on the London Underground?
No. There are no passenger power sockets on Tube trains, and none on the DLR or the trams either. Some stations have sockets in staffed waiting areas, but they are not a feature you can plan a journey around. Station wi-fi is widely available, which at least stops your phone draining itself looking for a signal.
How much does it cost to rent a power bank in London?
ChargedUp, the network you will see most often in pubs and shopping centres, publishes typical pricing of the first five minutes free, then £2 per 30 minutes, capped at about £12 per day. Prices vary by venue and the rate is displayed on the station when you rent. Keep the battery more than three days and you are charged around £25 to buy it.
Do London buses have USB charging?
Some do. Transport for London requires new buses entering the red bus fleet to have USB ports, and hundreds of vehicles already had them several years ago, but the requirement applies to the vehicle rather than the route. You cannot tell in advance whether the bus that arrives will have working ports, so treat it as a bonus.
Can I put a power bank in my checked suitcase?
No. The UK Civil Aviation Authority is explicit that spare batteries and power banks must travel with you in the cabin and never in hold luggage, with a limit of two power banks per person. They also must not be recharged during the flight. Check your airline's own conditions as well, since several have added rules about where the battery may be stowed.
Where can I charge my phone in London for free?
The most dependable free sockets in the centre are the public study desks at the British Library at St Pancras, which need no card and no purchase, and the desks in borough public libraries, which are open to visitors as well as residents. Museum and gallery cafés often have sockets along the walls, and airport gate areas have charging posts.
Sources
- ChargedUp - Frequently asked questions (pricing, capacity and purchase price) (checked September 2026)
- UK Civil Aviation Authority - Pack right. Safe flight. (power banks and lithium batteries) (checked September 2026)
- Transport for London - FOI-2161-2021: USB charging facilities on the bus network (checked September 2026)
- Heathrow Express - The onboard experience (checked September 2026)
- The British Library - Reading Rooms and study spaces (checked September 2026)
- Southwark Council - Space for you in our libraries (checked September 2026)
- GOV.UK - Hand luggage restrictions: electronic devices and electrical items (checked September 2026)