Due to changes to Royal Mail's shipping policy, we are no longer able to ship Lithium batteries in this manner. As such, we can no longer ship any Li-Po batteries internationally and our only current option within UK is to ship by courier at this time, resulting in the higher cost. We hope this is only a temporary requirement as we negotiate other options for posting.Li-Po batteries used in conjunction with efficient modern motors permit levels of performance and duration normally associated with I.C power. Unlike some brands, Impulse Li-Pos actually achieve the manufacturer's claimed capacities and continuous discharge rates. We rate them as being second to none.