Understanding USB charging standards

[MrM]

Long story short I have recently bought a new portable wifi scanner that will only charge when connected to a computer USB port. I knew this ahead of time; all the negative reviews are around the lack of ability to charge from a wall plug. I’ve tried a variety, as have others online, with no luck.

The charging cable is a USB 3.0 A (the slightly funny looking figure of 8 ish shape). Prior to purchase I thought it was something to do with the current output of the port and anticipated being able to get around this with a similarly low output (<750ma) USB plug but to no avail. I am now wondering, and assuming that it is something to do with a data handshake or similar that is absent when connecting to a wall plug.

Despite a lot of trawling online, my efforts have larger drawn a blank. One individual got around this using a “u disk mp3 decoder” where the device is powered by a mini USB connection and seems to get around the issue. Again I have not the knowledge to understand why this works. Whilst it’s an inexpensive solution, it’s not convenient.

Bottom line is I’m hoping to find a wall charger that I can purchase that will get around my issue.

Can someone kindly enlighten me as to what is likely going on here please?

 

[MrM]

Sorry, perhaps I’ve not explained the situation well enough. The scanner is made by Brother. They supply just a cable, saying the device can only be charged via a computer. And it seems this is true; it won’t charge when connected to a generic wall plug socket (they do not supply one). I am trying to understand why I can’t charge it from the wall.

 

[MrM]

Brother DS-940DW

 

[MrM]

I too found the advice on Reddit, and that’s great but I’d like a neater solution, hence me trying to understand what’s going on….

There is no app that opens when it is plugged in.