Your battery has a big capacity, most wall chargers are intended for smaller capacities. Lipos are charged at 1C which mean that your charger has to handle an output of about 2000 mAh.
Most lipo chargers which handle big battery capacities (like yours) need a DC source (a car battery in example) for safety reasons.
I have heard that some people have been using a used salvaged computer power source to power their DC type chargers (those AC computer power plants are capable to provide several rates of voltage, like 12 V; 5 V; 3 v: etc.