All of the light fixtures in our teardrop are marine which use a G4 bulb/array. I wanted spares (none have failed in five years) so ordered a 10 for $10 bunch from Ebay/China, Since I had them I decided to play with one to see if I could get it to fail, and connected two 12 in series and monitored voltage output and voltage with a 12V PMW buck converter. starting at 12 V and eventually up to 23.5V at which point two of the SMD's un-soldered themselves from the array, the rest still worked. This is the simplest (few components on the PC board) variety of LED driver.