The charger isn't usually the problem - its the battery. Different battery builds and qualities will have different maximum charging rates, even though the chemistry is similar. Since most electronics have batteries that aren't designed to be changed by the user - the only easy solution is an external backup battery that will accept a fast charge and has outputs to charge your other goodies when convenient.

RC Lipo batteries are available with incredible charge/discharge rates and a 11.1V battery pack or similar would interface with most 12V / 5V USB converters.