Having recently been involved in a 999 emergency call and challenged by lack of battery power, I have just been looking at Power Hit's disposable charger.  Whilst its seems useful as an emergency back up power pack, it provides no clue as to its shelf life.  It also comes in a sealed package which makes me wonder if it might be an air / zinc based battery so the package state is important.  Their web site is totally uninformative.  Has any one any clues about how long these devices can sit in one's rucsac?  (And remain useful!)

This says they are Li-ion.
https://www.digitaltrends.com/mobile/powrtabs-disposable-mobile-chargers/

This says Polymer battery.
https://www.alibaba.com/product-detail/Disposable-power-bank-single-use-mobile_60491581651.html?s=p

There are a number of these "disposable phone chargers" advertised on Alibaba (https://www.alibaba.com/showroom/disposable-phone-charger.html): some at least of these seem to be Li-ion polymer batteries.

Some of them seem to have a 1-year guarantee.

Does that help?

I've bought a number of small rechargeable 'emergency phone chargers'. Typically I never had one on me when I needed it. Hence I've had a few.

Now I have butchered one of the circuits from a cheap charger to allow me to plug in one of my caving light batteries for charging via USB. The circuit is tiny and can be kept in my emergency first aid tub that I take walking/ caving etc.

I figured that there is a much greater chance of my caving battery being charged/ having some juice as opposed to something that has been forgotten in the bottom of some kit. Also it's size means that carrying it is not a burden.

I've also hacked another circuit to reverse this and charge my caving batteries from a phone charger. This one lives in the car.

thanks for the info.  Li ion gives some assurance they will last for at least a year.  When I came across the emergency I was out walking rather than caving so had no light. 

I may be getting confused but what is wrong with taking a fully charged power bank out instead of relying on something disposable?

Inferus said:

I may be getting confused but what is wrong with taking a fully charged power bank out instead of relying on something disposable?

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Fair point.  My old power bank is larger than my phone and is also much heavier where as these disposable ones are so small in size.  That's their attraction.  Though I see modern power banks are lighter.  Thanks for bringing that to my attention.

I may be getting confused but what is wrong with taking a fully charged power bank out instead of relying on something disposable?

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You can get power banks that essentially have a single 18650 battery in that are quite compact. I've a couple from Lidl and they work OK, probably all come off the standard Chinese production lines with brand stickers attached as applicable.  All batteries have a self discharge curve http://batteryuniversity.com/learn/article/elevating_self_discharge so a cost effective 'disposable' one may eventually leave you stuck.  So charging up a rechargeable one as and when you when you remember may be a good way to go.  I've also tried a couple of the ones that take a single AA battery and found them to be completely useless.  Still I guess the disposable ones are compact and sealed, but a year isn't very long when you consider Energizer are claiming 20 year shelf life for their AA and AAA lithium prime cells and 10 for an alkaline.

Does anyone have any experience of the ones based on CR123 cells rather than AA. Varta certainly make one.

The CR123 would have a 10 year shelf life but not sure of the charge likely to be delivered to your mobile phone battery or whether it would be enough to allow you to use the phone directly (as against leaving it to charge the phone up and then use it - certainly a consideration in an emergency).

From a quick check, I presume one would need two CR123s as they only deliver 3v each but the disposable ones appear to have a 1.5Ahr capacity so would do if one dropped the 6 to 5v.  (Rechargeable appear to only have 0.5Ahr capacity.)  Are there 'boxes' available with the electronics and lead using CR123s as I did not find any on a simple goggle search? 

The Varta one is this one - search on Fleabay for "Varta Portable Emergency Microusb Mini Powerpack"

However you're right in that there doesn't seem to be anything about these on Varta's own site - discontinued ?

The result I get for Varta is a rechargeable with a capacity of 0.4Ahrs.  Varta itself offer a "Phone Power 800 Mini Powerpack. It is ideal for business travelers and people who want to listen to more music, phone or surf the internet longer ? anytime and anywhere. The Mini Powerpack provides smartphones and other USB-powered devices with additional power. The Phone Power 800 can be charged several hundred times via a USB port thanks to its Lithium-Ion technology, allowing for up to 150 extra minutes talk time per charge.** Once charged up to 80% of its power is still available after six months."  I don't view that as much of a gain.  It also quotes recharging for several hundred times for its other offerings. 

However Rayovac do one (PS72-BT6) but only in the USA, though there is one Fleabay seller willing to ship for treble the price!