Black and Decker Battery Charger Blinking Red (Bad Battery and Hot Cold Delay)

There are two types of blinking red pattern on the black and decker battery charger. My 18V/20V black and decker charger shows red light flashing. Fast Blinking Red: Means battery is bad. To solve this, you would need to connect the Positive terminal of one battery to another positive terminal, and negative terminal to negative terminal. After the reset, the bad battery should start charging again. Slow Blinking Red: Means Battery is either too hot or too cold. To solve this, let the battery temperature back to normal. After the battery temperature is normal, charge it again. A normal charging indicator on black and decker charger is blinking green,