Replacement batteries can be obtained to purchase separately through our Web-site. Please see Directions below on how to replace the battery – Exclusive treatment should be taken not to damage the PCB – we are not answerable for destruction caused by battery substitution. Some GPS trackers can function indoors, but https://medium.com/@trackerfit11/caravan-trackers-and-why-they-matter-for-theft-protection-dd44f62fcad7