Anker's Magnetic Battery 5K is a far cheaper version of Apple's
Anker 521 Magnetic Battery (PowerCore 5K) - Anker US
Amazon.com: Anker PowerCore 5000 Portable Charger, Ultra-Compact 5000mAh External Battery with Fast-Charging Technology, Power Bank for iPhone, iPad, Samsung Galaxy and More : Cell Phones & Accessories
Anker Mobile Power Packs
Source 2S18650 Battery for Anker SoundCore Boost 2600mAh on m.alibaba.com
Bluetooth Speaker Battery CS-AKS100SL For Anker SoundCore Boost Replacement Batteria 2S18650 AKKU 7.4V 2600mAh
Batteria 2S18650 per SoundCore Boost 2600mAh
Amazon.com: Anker Portable Charger, 313 Power Bank (PowerCore Slim 10K) 10000mAh Battery Pack with USB-C (Input Only) and PowerIQ Charging Technology for iPhone, Samsung Galaxy, and More. : Cell Phones & Accessories
Amazon.com: Anker 337 Power Bank (PowerCore 26K) Portable Charger, 26800mAh External Battery with Dual Input Port and Double-Speed Recharging, 3 USB Ports for iPhone, iPad, Samsung, Android and Other Devices : Cell
Power Banks - Anker US
Anker Power House Portable silent inverter battery 110V Outdoor JP | eBay
Anker PowerCore 26800 Portable Charger, 26800mAh External Battery with Dual Input Port and Double-Speed Recharging, 3 USB Ports for iPhone, iPad, Samsung Galaxy, Android and Other Smart Devices - Walmart.com
Anker 521 Magnetic Battery (PowerCore 5K) - Anker US
Anker 525 Power Bank (PowerCore 20K) - Anker US
Amazon.com: Anker Portable Charger, 737 Power Bank (PowerCore III Elite 26K) Combo with 65W PD Wall Charger, Power IQ 3.0 Battery Pack for MacBook Pro/Dell XPS, Microsoft Surface, iPad Pro, iPhone 13,
Review: Anker 521 magnetic battery (and compared to newer models)