small storage, fit straight into usb powerbank & easy to balance.
cheap & good
https://m.aliexpress.com/item/100500423 ... 6839%21rec
If folk have a plethora pf powerbanks (like we do) we stick these in the same collective drawer & elastic band them to the PB when we travel as extra "to hand" light in case of power loss, ..as well as mandatory petzls.
Phones are not emergency lights, we'd prefer keep them for calls & location purposes, ..very unfashionable but there you go!

I've shaved with my DE razor using just one of these, successfully I hasten to add. (& other test conditions)
For stairwells etc I just use a small strip Pir, 4x AAA magnetic strip with 3M scotch tape combined mounting (as per spec) ..its had a few years of continuous use & is a rare success where ali express are concerned, but you have to know the product because sellers know naff all when you want to verify something on a generic they sell blindly!
I also have one with a magnetic wall screw point that allows the light bar 90 degree rotation, as well as the pir having separate rotation to fine tune the activation zone.
I think these are worth thinking about so you don't necessarily have to have a torch / headtorch to hand in some areas.
I have a mains router battery adaptor (runs off a powerbank) to take over the job if house power goes down when im about, effectively matchbox size, so we can continue using our tablets etc, all depends what mobile data you have set up / want to run cameras etc over a longer outage type thing.