Phone Charger Vending machine

[DaveLembke]

At work yesterday a coworker pointed out that I guess some places are putting in phone charger vending machines. In one funny photo there was the vending machine there plugged into the wall and on the floor plugged into same outlet someones phone with its charger getting a free charge. So funny that they dont hide access to the power to bypass paying.

Funny that they dont secure your phone, you have to stand there and wait for 30 minutes. 

I havent seen any of these yet. Last time in an airport people have stuff plugged into any outlet they can find as well as airport had in place USB power plugs at bar tops to connect to for free.

Myself I keep two 5000mAh battery packs on hand charged so i can charge my phone or tablet which has a low current and tablet higher current option or both at same time and no having to find an outlet anywhere or plug into a questionable free USB power that could be a data hack connection if planted somewhere for people to think it belongs there for all to use. 

I had some pocketjuice chargers but they were only good for 1 phone charge or partial tablet charge at 2200mAh. These other shen zhen 16wms126 5000mAh battery bank chargers fit better in my pockets and I like the LED display that shows 0 thru 100% to know how much charge is left or if its fully charged or not vs just primitive LED Bar for 25/50/75/100% charge.

 A guy at work has a 22,000 mAh the size of a large scientific graphing calculator but I have read about many of these with ( exaggerated ) mAh ratings so i have avoided the larger ones that might just contain a battery that is 10,000. I bought one of these 5000 mAh to test it out first as for the blue digital LED display was a selling point initially. When happy with one of these acting like the charge life of two of my 2200mAh chargers and able to charge 2 devices at same time I then bought another for $10 because it seemed to be true to 5000mAh and my Tablet would charge from it without battery bank getting hot from heavy current draw like the others I have.

[attachment deleted by admin to conserve space]

[Geek-9pm]

Here is another idea.
How to Use AA cells to charge your phone.
Do a search on the above and find videos and vendors.
You can find a thing on Amazon under $5 that will hold four AA cells and has a USB connector. You have to buy the AA batteries.
Also on eBay.

[DaveLembke]

I bought one of those at our local Dollar store for $1.00 out of curiosity. It takes two AA batteries and has a circuit that takes 3 VDC and regulates 5 VDC from a interesting chip. Probed around on the chip with my oscilloscope and its the coolest chip, but its not cost effective to burn through AA Batteries to charge a phone. Additionally the chip runs rather warm in this voltage ramp process. I figured I would use it as a final drain from weak AA batteries to give a phone a small charge before tossing them out but by the time AA batteries start to dive in health they dive pretty quickly with conversion process of a chip that ramps up voltage at a lower voltage with heavier current cost.

[Geek-9pm]

What you say is true.
The value of the gadget is when e you have no recourse.
The old school carbon-zinc cells are very cheap in sold  bargain stores. Documentation on the carbon-zinc cells show they have a log shelf life for the cost. You  might buy a lot of them and keep them in you emergency kit. When you factor the cost, shelf life and yield, it  starts to make sense.

https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery
The above article does not clarify that the carton-zinc does shelf life better if you consider the low cost as a factor. But it does say:

Continual improvements were made to the stability and capacity of zinc–carbon cells throughout the 20th Century; by the end of the century the capacities had increased fourfold over the 1910 equivalent.[1] Improvements include the use of purer grades of manganese dioxide, better sealing, and purer zinc for the negative electrode. Zinc chloride cells (usually marketed as "heavy duty" batteries) use a paste primarily composed of zinc chloride, which gives a longer life and steadier voltage output compared with ammonium chloride electrolyte. Manufacturers must now use more highly purified zinc to prevent local action and self-discharge.

This is about shelf life of virgin cells. After the first use, they decay rapidly.

Put another way, modern alkaline cells have much more energy, but decay over a span of two or three years. The carbon-zinc stall  has most of its  even after three years of proper storage. So, for emergency use, they are the choice.

[soybean]

I keep two 5000mAh battery packs on hand charged so i can charge my phone or tablet which has a low current and tablet higher current option or both at same time

Yeah, those type battery packs seem like a good solution for charging when an outlet is not available. I have one rated at 8000mAh and, like yours, it can charge two devices at the same time.   

[strollin]

I have bought a number of those battery packs to use for backup power over the years.  The problem for me is that I can't remember to keep them charged so when I actually need to use the pack, it's most likely not charged.  I have the same problem with cordless hand tools like drills or screwdrivers.

The AA pack chargers seem like a plausible solution for me since I can buy AA batteries to put in them almost anywhere.

[Geek-9pm]

...
The AA pack chargers seem like a plausible solution for me since I can buy AA batteries to put in them almost anywhere.

Right!
The cheap carbon-zine AA pack swill Last on the self as long as the more expensive kind. After four years a normal temperature they still have half or better of capacity. This has been documented by
 EverReady,
 Burgess and
 US National Bureau of Standards.
he research was done many, many years ago and now the recipe is being used to make the cheap batteries from across the Pacific.

[BC_Programmer]

Yes because one of the primary reasons I buy batteries is because I want to leave them unused on a shelf.