This is from their website. From this I would venture to say you should disconnect the entire thing from both the wall and batteries. If that doesnt work, you have a bad charger and/or batteries. I know you said theyre new, that doesnt mean they arent defective. Q.What does it mean if I have a blinking light? A.If you are getting blinking lights there are two things that could be going on.1. There could be a problem with your charger.2. There could be a problem with your batterie(s) (even if they are new).The first thing to check is to see that the polarity (negative and positive) has not been reversed. If they are set up correct, then disconnect the leads from the batteries and with the end of the leads not touching anything turn the charger on. You should get a solid green light and the output of the charger should be 13.3 volts. If the light(s) still blinks then there is a problem with the charger. If you get a solid green light the next step is to isolate each of the batteries, by doubling up the leads on one of the batteries. Repeat this until you have isolated each of the batteries. If it blinks on all combinations of the batteries, then there is a problem with the charger. If it blinks on one of the batteries, then that battery is the problem. v Battery Isolator FAQs- Chaz