Mighty Max Battery 6V 4.5AH SLA Multipurpose Rechargeable Battery Rechargeable Sealed Lead Acid 645 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com
Tenergy 4/5 Sub C replacement battery (rechargeable)
4-Way 18650 Battery Holder - DFRobot
Amazon.com: 4 Volt 4.5 Ah Sealed Lead Acid Battery for Fi-Shock SS-440 : Health & Household
PLUS POWER 4,5V | Duracell Primary Battery, 4.5V, 4.5V, Alkaline | Distrelec International
Duracell 4-5 Volt Battery 3D model | CGTrader
Tenergy 4/5 Sub C 2000mAh NiMH Rechargeable Battery - Tenergy