Automatic 12v Portable Battery Charger Circuit using LM317
Super capacitor power bank - The 5 minute charger DIY - Hackster.io
MCP73871 Solar Lithium Battery Charging Module DC 5V Lipoly Polymer Charger Board with Capacitor for Outdoor Power Bank DIY : Amazon.ca: Industrial & Scientific
How to Make Battery Charger at Home : 6 Steps (with Pictures) - Instructables
Battery Desulfator: A very simple capacitive battery charger made from scrap parts | Battery charger circuit, Battery, Battery charger
Capacitor, Capacitive Battery Charger Circuit. | Miscellaneous Circuits and a link.