Game Boy Color/Pocket/Light 3.3V USB Cable
It bugs me when people use standard 5V USB lead to power their consoles - yes it works but its not great for the console designed to work off 3V. I couldn't find proper power cables off the shelf, so I've had them custom made.
The cable drops the 5V USB voltage down to 3.2V, which is very close to the supply of 2 AA batteries (1.6v each = 3.2v).
The lead has a male USB 2.0 plug on one end and a 2.5mm straight DC barrel jack the other; they're 1.2m long.
This cable is the same for Game Boy Color, Game Boy Pocket, and Game Boy Light consoles.
Review for Game Boy Color/Pocket/Light 3.3V USB Cable
Gameboy Color Power Lead
I have been searching for a power solution for my GBC for a long time. I scoured ebay for the old mains powered adapters that were available at the time but could not find a suitable solution. Then I found this. A neat little cable that can be used with any power source including mains connections and power bricks. I have saved a fortune on batteries! I cannot recommend it enough!
I wouldn't trust any other cable for USB power to your GBC. This works perfectly with my portable battery if my AAs run out of juice. I had another cable I bought from HHL and it concerned me with how it was functioning (half the time it worked, half the time it didn't) and I think it was sending the wrong voltage which could lead to potential hardware issues in the future.
REALLY happy with this! Highly recommended.