Owned this MZ-R55 for 20+ years and only noticed today that you only need one AA battery (not two) in the sidecar. Makes sense now I think about it as the gum-stick
5400 Maverick / 5400 MZ Magnum / 5400 ZT Elite Bad Boy replacement battery
NiMH battery retrofit for Metz 76 MZ-5, 70MZ-5 type 76-56 | for Lamps | Accumulators | Products | Akkuplanet
Lip-3wmb 570mah Battery For Sony Mz-n10 Md N10 Batteries With Tool - Mobile Phone Batteries - AliExpress
Garrett K-12 School Package includes MZ-6100 Walk-Through Metal Detector, Hand-Held Super-Scanner V, Backup Battery, Caster Set for Easy Mobility, 3 Year Warranty - Dana Safety Supply
Amazon.com: Estry Battery Replacement for LIP-12 MZ-R30 MZ-B3 MZ-E3 MZ-R2 MZ-R3 MZ-R35 MZ-R4 MZ-R4ST LIP-12H : Health & Household
Amazon.com: HQRP 2-Pack Battery Compatible with Sony MZ-R90 MZ-R91 MZ-R900 MZ-R900PC MZ-R900DPC MZ-RH10 MZ-RH910 : Electronics
Pentax MZ-30 Battery
3D Printable SONY MD Walkman MZ-R90/91 Battery Door (Part# 4-223-077) by Sven Enterlein
KeyTek MZ-15/EC for sale $4995.00 | | AccuSource Electronics
Sony MZ-E80 [MiniDisc Wiki]
Battery Swap: Pentax MZ-50 - YouTube
Walkman Battery 3.7V/2300mAh LIP-12, LIP-12H for Sony MZ-B3, MZ-E3, MZ-R2, MZ-R3, MZ-R30, MZ-R35, MZ-R4, MZ-R4ST - AliExpress