/diy/ - Do It Yourself

Try a FagPower instead.
Probably it can't draw 5A from that piece of shit battery.
Also some transformers (what you liberal cunts call power bricks) are made not to work only with approved devices. Once I had a US Robotics modem and there was fucking literal DRM on the 9V power supply. They were doing something with pulse modulation or whatever the fuck so the modem only accepts their transformer,