I just got the ODF30C light and the ODL20C from Banggood. Both of the lights manuals say the charging LED in the switch goes from Red to Blue at completion of charging. Both of my lights slow blink Red when charging and then go solid Red when charging complete. I verified this by removing the cells when the LEDs turned solid red and measuring cell voltage with my Fluke 115. Both are at about 4.18x. I even put the cells on my icharger 4010 and ensured they terminated at a 4.20 V charge at 10% termination current. I put the cells back in the lights and plugged the charging cables back in with the same result. Both are solid red. I left them both plugged in for an hour after turning solid red hoping for blue but no dice. I've never seen the Blue?
Here's another interesting occurrence. With the ODL20C, when fully charged from a tiny high Amp Samsung Galaxy8 120VAC charge cube, when the charge is done, the LED goes from slow flashing Red to fast flashing Red, – almost like what is described in the manual as the "low battery, charge it up" alert – which I have not yet seen as I have not run the battery down. With other charge cubes, this does not happen. It terminates with a solid red.
Here's another interesting occurrence. With the ODL20C, when fully charged from a tiny high Amp Samsung Galaxy8 120VAC charge cube, when the charge is done, the LED goes from slow flashing Red to fast flashing Red, – almost like what is described in the manual as the "low battery, charge it up" alert – which I have not yet seen as I have not run the battery down. With other charge cubes, this does not happen. It terminates with a solid red.