Solid Red Light
When the green light on the Nintendo DSi turns to a solid red the system is telling the user that approximately 30 percent of the system's battery is left for use. Users have reported playing times up to one hour from the time of a solid red light. Times will vary based on the game you are playing due to more computing power being used by more complex gaming titles.
Flashing Red Light
When the red light is flashing during game play or when the gaming console is turned off, the battery is nearly depleted with an average of less than 30 minutes of battery charge time remaining. Time remaining will once again be affected by the complexity of the game you are playing.
Turning Off the Red Light
The Nintendo DSi red light located on the middle console will only flash red or turn to a solid red when battery levels are low. Nintendo suggests a four hour battery charge time to full replenish your DSi battery and turn the light back to green.
Red Light Displays Orange Blinking Light While Charging
If you have plugged in your Nintendo DSi and the charge indicator shows a blinking orange indicator, check that your battery is installed properly and is firmly in place. Nintendo DSi batteries are good for approximately 500 charges and may need to be replaced once the red indicator flashes or turns solid in the off position and an orange indicator begins blinking when attempting to charge the system.