Blue Battery Operated 5mm LED Lights, Green Wire - Wintergreen Corporation
1~5 Pre Wired 5mm LED 9 Volt Red Flashing On Snap 9V Battery Clip Blink Flashing | eBay
I soldered these 5mm LEDs (sorry, no datasheet) in series, but only the green ones light up and dimly. Should I use 3mm LEDs to light up all 5? I want to