AA battery blinks red when inserted in charger. Is it dead?

Ok all mine had the same problem however problem has been solved! The power cord that plugs into the charger is a common cord you may have laying around the house. I switched the power cord to my charger and the dreaded blinking stopped! Its just a bad power cord to the charging unit! Hope this helps!

If these are old batteries, one or more may be dead.

I had the same problem with flashing red lights. Both sides on a four battery charger. I swapped the batteries to another charger and the batteries were fine. They charged normally. I put some different batteries in the charger and the same flashing light situation. Those batteries also charged normally in a different charger. I looked closely at the back of the charger and, low and behold, "made in China". Why does that not surprise me. The bottom line, it may not be a battery issue.

All chargers cannot charge all types of batteries. Are your Duracell batteries NiMH or Alkaline? These indications generally happen when you insert a battery type that is not rechargeable.

Try a new or other charger, problem may be with the charger.

gripfitter is incorrect, that charger is made to charge in 15 minutes. It has a cooling fan and when batteries are inserted a red light comes on and the fan starts. When light goes out and fan stops, the batteries are charged. (light should not blink as that indicates one or more of the batteries has a problem)

When the duracell lights blink during charging, AT YOUR OWN RISK, try a reverse charge. Instead charging positive to positive and negative to negative, try positive to negative and negative to positive. I did this for 2 minutes. This solved the problem. After the 2 minutes, I gave the batteries a normal charge. You will have to force the battery and charger contacts to touch.

It is supposed to stay on. If it is blinking then your battery has gone completely dead. You can force the charger to charge the battery by applying a voltage (AA battery w/ wires worked for me) across the charging terminals while inserting the battery. You'll have to take the charger apart for this.

put one battery at a time ,when it turns red that battery is bad.