Option B. - Battery + USB cable.
USB CHARGING 9V RECHARGEABLE Li-Ion BATTERIES 10800mAh 9 VOLT BATTERY. UK SELLER
2PCS 9V Rechargeable Batteries 1300mAh, 9V Rechargeable USB Lithium Long Lasting Battery, with 2 in 1 Charging Cable, for Smoke Detectors, Alarms, Keypad, Microphone
4 Pack 9V Rechargeable Batteries 1300mAh, 9V Rechargeable USB Lithium Long Lasting Battery, with 2 in 1 Charging Cable, for Smoke Detectors, Alarms, Keypad, Microphone
Massate 4 Pcs 9V Rechargeable Batteries 1300mAh, USB C Rechargeable Lithium Ion Battery with 4 in 1 Charging Cable, Long Lasting 9 Volt Battery for Smoke Detector, Guitar Pedal, Microphone
ENEGON 9V Rechargeable Battery,12150mWh High Capacity Lithium Batteries, with USB-C Fast Charging Cable, Ideal for Smoke Detectors, Microphone, Alarms, Toys, Torches, Medical Devices etc,2-Pack
9V Li-Ion Rechargeable Battery & USB Charging Cable + LED Device (PP3/6LR61)
