To charge the battery plug the system directly into a wall outlet using the AC adapter (included). When the Nintendo DSi XL battery pack is fully charged the recharge indicator LED will go out.
If this does not solve the problem, try using a different original Nintendo DSi XL AC adapter with your Nintendo DSi XL if possible.
If the Nintendo DSi XL does not function with a different AC adapter, the Nintendo DSi XL will need to be returned to Nintendo Australia for inspection/repair.
If the Nintendo DSi XL does function with a different AC adapter, you can return your AC adapter to Nintendo Australia for inspection/repair.