This Shure FP11 amplifier doesn't come with a battery. There's a known issue: when you put a battery in the unit, the connection might not be firm enough to power it on. You'll need a wedge (not included) to push the battery towards the contacts.

To use the Shure FP11 amplifier, first make sure you have a battery. Since it's not included, you'll have to get one separately. When inserting the battery, be aware that the connection may not be strong right away. You might need to find a wedge to push the battery towards the contacts to turn the unit on. As for maintenance, keep the amplifier in a dry and clean place. Avoid exposing it to extreme temperatures or moisture. If you face any issues with the battery connection, check if the wedge is properly placed. That should help you get the most out of your Shure FP11 amplifier.