radio battery charge
 

Hey folks, I have a Wouxoun KG-689 radio and I have an issue...I charged it some weeks ago but when I turned it on yesterday, batteries where dead. Now, I want to charge it for the game tomorrow but when I put it on the charger, the LED is red flashing...isn't it supposed to be continuous red till it turns green when its done ? last time I removed it after an hour or two of the charger 'cause I didn't want to overcharge it...the LED was still red....

is it normal ?