Almost got scammed by Rad Bikes this way. Battery mysteriously failed 10 months into their 1 year warranty. Rad Bikes accused me of sabotaging the battery and refused to honor their warranty, but “generously” offered me free shipping on a $300+ replacement battery. Turns out the off-the-rack fuse they use blew; identical down to the manufacturer to the ones used in cars. Replacement fuse was <20 cents and fixed the problem instantly.