Amazon with TIGER HEAD HI WATT BATTERY HK CO LTD has the 4-Pack HW AA USB-C Rechargeable 1.5V 3600mWh Lithium Batteries w/ 4-in-1 Cable for $14 - 20% off with coupon code Z2CA9EG8​ at checkout = $11 with free shipping on $35+ or with Prime.

• The 4-Pack HW 9 Volt Batteries are $13 using code XGZEEG9B