4PCS 1300mAh 9V Rechargeable Batteries with USB Fast Charging Cable

Customers find these batteries to be of high quality and easy to recharge, working well with various devices including guitar tuners. The battery life receives mixed feedback - while some say they hold charge very well, others report they won't take a charge sometimes. The value for money also gets mixed reviews, with some finding them good value while others say they're not worth the cost. Several customers mention the batteries are really noisy.