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The right charger for 220 V AC wall outlets, would be one made for use in Australia (esp. if the outlet type matches... I'm not sure it would in the Philippines.)
As for the output voltage of the proper AC Adapter... that would likely be about 3 V, since most cell phones use 3 V rechargeable batteries... but I am by no means sure of that. Nor do I know offhand what charger plug your model of cell phone has - whether it charges through the multi-pin connector or through a somewhat standard DC plug. With that information, I could recommend something specific to buy over the internet, if that is what would serve best.
Perhaps just using a 'standard' US-type charger for this device would be OK, if you also used a step-down transformer (that takes the wall outlet as input at 220 V, and steps it down to 110 V AC. In other words an adapter transformer - not just an adapter plug - for use of US appliances on Australian power.)