Advances in the technology of biotelemetry are transforming the ways in which we remotely acquire environmental, physiological and behavioural data. Large and heavy batteries, however, continue to reduce the availability of GPS tracking devices for small taxa and for species with morphologies that limit attachment options. Device miniaturisation is beginning to be achieved through the use of in-built solar accumulators, but it is important that the rapid uptake of these technologies does not outpace systematic tests of their precision and performance. Here, we share the technical details of a new 180g solar-powered device originally designed for vultures but adapted for use on terrestrial herbivores. We test the precision and performance of this device using both stationary and animal-borne trials across multiple geographical areas. Our results show exceptionally high fix acquisition success rates and moderate precision error. We also demonstrate that these solar-powered devices maintain a high and stable voltage over long-term animal-borne trials. These results highlight the importance of a-priori testing of new technologies in biotelemetry research and demonstrate how solar-technology can help to address some of the challenges we face in tracking terrestrial mammals.