Low current USB power supply

Hello, I am searching for a USB power bank which does not switch off automatically when it detects the current is too low.

Hi Johan,
Welcome to the Digikey tech forum. Take a look at these power banks to see if one is the style your looking for.

Hi Steve, I have reviewed indeed these datasheets before posting this topic. It doesn’t mention auto power off, but almost all power banks (except 1) have this as a standard feature. So if you can confirm it doesn’t have the auto power off I would like to test if it is indeed the case. Then we are able to offer this product to our customers.

The data sheets for these have an Un−Loaded Voltage specification, therefore they must not turn off automatically when the load current is zero…

Hi Paul, thanks for this. But… opening these pages result in a 404. I also tried to search on article number, but this seems not supported on your website (or I couldn’t find it). So can you please send me a link which also opens for me?

Hi Johan,

I’m not sure why those pages aren’t opening up for you. Maybe try the ones below:

Or try a new browser perhaps? Also the data sheets are located below:

Hope that helps.

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Hmm, the DikigKey URL’s are giving you 404’S

They were chosen from the previously posted search list for power banks

Try just putting the part numbers in the search box

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Hi Paul,

Also no success…

But I was able to download the datasheet through the link you provided.

The 57-PB1 looks sufficient for me.

I am very interested to see if this device doesn’t power off.

How can I get one for evaluation?

I still cannot find it on your website www.digikey.nl. I tried it also on www.digikey.com, where I found the part….

Wow your web browser is severely broken if typing the part number into the basic DigiKey search box gives you 404’s.

Hi Paul,

I discovered the reason.

The part only is available on digikey.com, not on digikey.nl.

So please inform your IT collegues :wink:

Best regards,


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FYI I do not work for DigiKey

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Hello johan,

When parts are not available to sites of other regions (in which it does not show up during a search nor will links bring them to the part page), the parts are not able to be shipped to those locations (for at least one of multiple reasons). The website is working as intended; it was not known that you were not on the .com version when the original links were shared. Apologies on the confusion.

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Unfortunately this would appear to be more of a voltage regulation specification than an indication of overall device behavior. Per p.5 of the document for the PRT-15593:

Insofar as low-load shutdown is a standard feature for this type of device, its absence is likely to receive specific mention. voltaicsystems.com is one entity of which I’m aware that offers such products.


Nice catch, another manufacturer distributing misleading specifications, sigh.

It would at least be a reason they’d have to give my money back by law, since they clearly state the voltage it will provide at 0mA and misleading documents are actionable under law.

Hi Rick, I am aware of the products of this company, but cannot image they are the only supplier of such products… Is the market so small?

NTE Parts Direct may sell the to the Netherlands.

FYI I’d estimate that in the total market for portable cell phone chargers, less than 0.01% of buyers want one that provides voltage @ no-load. The reason many low cost “lipstick” housed units do it is most likely to save on the cost of automatic shut off.

I have a generic (no manufacturer or part number) one here that was bought as part of a 10 piece for $10 order by my sister years ago. It even passes through current while charging so I added circuitry to make it a one off mini-UPS for a PiZero serial data recorder in my test lab. Been working well for about 4 years now.

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