Not my daily driver (yet?), but made a custom dumbphone by getting a Nokia 3310 without a battery or charger and implanting a 2500 mAh Li-Ion cell and a USB-C port (details
NOKIA » Nokia 101 NMT - 1992
Battery BL-5CA compatible with Nokia 100, 1200, (Li-ion, 3.7 V, 700 mAh, Original (PRC)) - GsmServer
Nokia no longer bothering with holograms on most batteries?
Cheap Dual Sim Nokia 101
Amazon.com: (2 Pieces) BL-5C Battery, Upgraded 3.7V 1600mAh Li-ion Replacement Battery for Nokia, Household Radio : Cell Phones & Accessories
Battery for Nokia 101 by Maxbhi.com
Battery BL-5CA compatible with Nokia 100, 1200, (Li-ion, 3.7 V, 700 mAh, Original (PRC)) - All Spares
Kastar BL-5C Battery 2-Pack Replacement for Nokia 100, 101, 106 Dual Sim, 207, 208, 215, 220 Dual Sim, Olympia Chic 2, Philips Avent SCD610, Phonak Dect CP 1, Phonak Dect II, Prunus L-218AM - Walmart.com
Kastar BL5C Battery Charger for Nokia 100, 101, 106, 207, 208, 215, 220 Dual Sim – ASA College: Florida
Front Frame Battery | Housing Cover Case | Nokia 101 Housing | 101 Nokia Cover - Nokia 101 - Aliexpress
Genuine Nokia 473206A.101
Genuine Nokia 474907A.101
Original Nokia 101 100 Battery Cover Back Rear Cover Black | eBay
Nokia 101 mobile phone black without: battery, charger, battery lid display broken | eBay
Replacement Battery for LG LGIP-531A Envoy II - Battery Warehouse