How to power multiple HDD 3.5 externally?

Question

Hard disks

Good afternoon, tell me pliz what are the options to power several (for example 4 or more) HDD 3.5?
- Not using the PSU of the current computer
- I use ONLY the connector for powering the HDD, I can not touch the data connector.

Thanks in advance for any thoughts :-)

Answer 1

Taking into account the fact that these wires are essentially not connected to each other in any way, just from any other UPS, forcibly turning it on, that's all

Answer 2

External power supply with confusing powergood