You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Need something with a big capacity. My daughter needs to keep her phone a diabetes monitor topped up on a 7 day camping trip.
Not interested in a solar one.
Anker - however much capacity you need. I’d probably go 3 or 4 20000mah for some redundancy.
For reference, one of those will keep a garmin & iPhone topped up for 2.5 days*
* as long as you aren’t playing candy crush for 5 hours straight.
Anker or iniu on amazon a couple of 20000amh should be work
keep an eye on hukd been some real cheap deals I paid £14.40 for a 20k INIU last week
Another vote for Anker. No idea on capacity as that'll depend on use and devices.
Maybe two smaller / medium sized ones to guard against an issue with one or other and potentially more useful for the future?
Whichever capacity Anker is the only right answer
Consider your requirements for charging / discharging speed in addition to capacity.
Ideally get something that has power delivery input and output.
I would normally say Anker
however
When we bought some power banks for a cycle touring trip last year, Anker were definitely behind the curve for charging input to the bank itself.
For cycle touring, we wanted power banks that would charge very quickly e.g. at cafe stops.
Went with this. Unknown to us brand, but have been decent so far.
Not sure if Anker has moved on since
Another +1 for anker but dont use a shite charger. I got a higher capacity usb-c charger to charge my anker 20k mah power bank. Charges relatively really quickly.
keep in mind that if you can charge a 20k powerbank to full at a cafe stop you’ve been lied to about capacity on amazon!!.
also keep in mind if you intend to take on a flight then i theory you’re capped at 20k mah in cabin luggage i think it is.
Sorry, not really answering the question but had she got a finger prick monitor as well? I had a stressed out Cub camp where I was worried about battery life before remembering I carried it round with me every day with my hypo stuff. So used to just using my phone I'd forgotten!
(Anker power bank user here, I have two - one light small one and one bigger for charging my phone with glucose monitoring)
I got this Anker power bank, could probably power a house from it:
About £35 on offer at the mo.
keep in mind that if you can charge a 20k powerbank to full at a cafe stop you’ve been lied to about capacity on amazon!!.
I didn't say I was expecting to take the battery all the way from 0% to full during a cafe stop....
The point is that if your time available to charge is finite, then the charging speed is important. It doesn't really matter whether you fully charge in the available time or not, just that you bang charge in there as fast as possible.
The battery I linked to above takes a little around 2.5 hours to go from empty to full on a 40W charger.
That works out about right ((40 watts * 2.5 hours)/5v) = 20ah
Yeah I haven't measured it's discharge capacity with an ammeter etc. but on the face of it from charging speed, it seems legit.
keep in mind that if you can charge a 20k powerbank to full at a cafe stop you’ve been lied to about capacity on amazon!!.
The Anker Prime 27650 can be fully charged in 37 minutes.
Would also go Anker, but mainly because they are an established and well known company that'll have a higher quality product than a ChinFire off Aliexpress.
INIU is a very respectable brand IMO. I've had a few bits of theirs and it's all well made, reliable, and battery packs seem true to quoted capacity values.
This is £23.37 after discounts and offers 65w charging for itself and for other compatible devices. 20,000mah capacity

And if you want real fast charging whilst being airline compliant this is 100w in/out and 25,000mah capacity.
It's usually around £28 with vouchers so just check daily until they offer the 40 or 50% voucher
Anker/Tecknet etc. all do decent products.
If possible, I would recommend putting the phone in airplane mode overnight - it will barely lose any charge overnight if she does this.
Couldn't she just take her sensor's dedicated monitor with her? I appreciate for a two week period she'd be locked into using the monitor rather than her phone, but there'd be no stress about recharging.
Consider your requirements for charging / discharging speed in addition to capacity.
Ideally get something that has power delivery input and output.
Big +1 on this point - some of the power banks out there are very slow to charge, which is fine if you're plugging in overnight, but not ideal otherwise.
And another +1 to INIU, I've got a 20,000 bank and it's excellent.
Couldn’t she just take her sensor’s dedicated monitor with her? I appreciate for a two week period she’d be locked into using the monitor rather than her phone, but there’d be no stress about recharging.
She's not going for 2 weeks. She uses her phone as a phone and her monitor as a monitor, but it will still need charging at some point. Backup is a pin-pricker and uses AAAs, but that is only a backup.
Will look at some of the suggestions above though, thanks. I get power banks from work, but they are promotional gifts and are a bit crap so it is helpful to have some feedback on reliable brands.
NIU is a very respectable brand IMO. I’ve had a few bits of theirs and it’s all well made, reliable, and battery packs seem true to quoted capacity values.
I have also heard good things about them. I heard on reddit that they supply other makes or that they have the same parent company
https://www.reddit.com/r/UsbCHardware/comments/zbe1ra/iniu_products_what_do_you_guys_think/
cheaper direct it seems - £46.99
https://uk-main.iniushop.com/products/iniu-power-bank-b63-25000mah-design-for-laptop2
I have an old 20000mah Anker and its been great for a number of years now. However, it doesnt last a long weekend camping trip. Last year I bought a 60000mah powerbank, unknown gamble, but its been very good.
https://www.thebasictech.com/product/o2-project-yt-2030/
Lasts about 4 nights and chargers fairly quick using the usbc.
keep in mind that if you can charge a 20k powerbank to full at a cafe stop you’ve been lied to about capacity on amazon!!.
Depends, right?
Some of the newer ones will take high power PD input. At 140W, that's only a little over 30 minutes.
When we bought some power banks for a cycle touring trip last year, Anker were definitely behind the curve for charging input to the bank itself.
Anker have had fast charging power banks for quite a while. Certainly over a year. They do cost more than their "normal" power banks, though.
Thanks @cp - my (very) old Belkin is getting a bit tired and it's USB-A and Micro which fits virtually nothing I want to charge now. That ^^ looks a good solution. I've always used Anker but my last two were 'donated' to the offspring when they left home.
Power bank you say.....
Just got an Anker PowerHouse 555 (1024Wh)

Obviously no use to the OP and not exactly camping trip friendly, unless the car is nearby, but will live in the Land Rover for site use. Should get almost two ebike charges out of it too
If anyone is still looking Amazon had an Anker 10 000mAH slim bank for £16 earlier this week.
40% off one of these makes it £11.99 (only one purchase at discount) -I've ordered as I find I can charge 2x S23 Ultras from about 20% to full before needing recharge from a 10,000 mah charger. Also plan to be charging by solar when camping.
INIU Power Bank, Portable Charger 10000mAh Slimmest & Lightest High-Speed USB C Input
I was so impressed with the INUI initially recommended, I bagged a one day offer on the mag-charger which means you can still use your phone (it's a bit cumbersome) while it recharges. Also no cables so very convenient. It doesn't charge as fast as a cable but it's more than good enough considering it's portability/ease of use.
The INUI 10000 mah at £11.99 (40% off) turned up today. Pack has a link to getting another for the same discount.
I've had many power banks over the years and bought this one from Amazon a couple of weeks back. I've been impressed with it so far. It outputs usb C PD at 100 W and has built in C and Apple cables. I thought these would be a bit gimmicky but I've found the really useful. Its a bit of a lump but is a good shape to fit in a bag. No idea if the capacity is accurate but it feels well made. Half normal price at £40 1the moment and so impressed I'm thinking of ordering a spare.
VEGER Laptop Power Bank 25000mAh,100W Fast Charging USB C Portable Charger,QC 3.0 Battery Pack with 4 Outputs Compatible with iPhone14-8/Samsung Series Phones,iPad,Tablet,MacBook,Dell, and Mor https://amzn.eu/d/4hSo6vA
Topper