Problem Charging from Y-Cables that Appear to be Made for Charging

I use a Samsung Galaxy S5 in a robot. Keeping robot and phone batteries charged is a constant issue. So I’ve acquired a bunch of different Micro USB3 to USB A Y-Cables in hopes of charging the phone from an on-board power bank while running the robot.

Multiple charging sources all work fine with normal (non Y) charging cables. Yet none of several Y-Cables work to charge the phone… It doesn’t even matter if the data cable is plugged in. With the phone off, I can go straight from a reliable charging station to the phone using the charging part of a Y-cable and it fails. All I get it the periodic empty battery image on the screen as it starts to attempt to charge. Then it shuts off charging as though it detected something wrong.

Some of the cables I’ve tried are:

Can anyone explain why this doesn’t work? And more importantly, is there a solution?

Thanks in advance.