This rechargeable GB-10 battery gives you up to 8 hours of high-headroom analog mixing with the ProFX10 GO battery-powered mixer. It's the same GB-10 that comes with every ProFX10 GO, so it's a perfect replacement or spare. The GB-10 can charge inside or outside the mixer, making it possible to charge a battery at the wall while using another for the mixer. When one battery runs out, swap in the spare to double the battery life. Should you play a 16-hour gig? We can't answer that. But if you want to, this spare GB-10 battery can help make it happen.