There's no reason to connect it to the 5v source, the batteries are capable of powering an LED. This will just defeat the purpose of having a battery indicator LED. You'll just need to adjust the resistor, or maybe remove it/bypass it. You'd need to know the input voltage.

Best to stick to buying LEDs from retailers that provide datasheets to avoid problems like this.

For reference, what's the protocol for replacing cgb leds? Are there a standard for cgbs or do you always have to do some wiring?

You can wire up the led to the +5v and a resistor:)

Oh.

Was intended for dmg

I recently bought a blue water clear led from nonelectronics and put it in my kiwi cgb. It came on for a little bit but faded off in like a couple of minutes. I put in some new batteries and the same thing happened. I also tried to re-solder it but it still wont stay on! Could someone please tell me whats going on and how i could fix it.