Any idea what this PS1 memory card with a battery could be? Board is cut to fit inside memory card shell, so looks custom. Got it with a modchipped PS1, not sure
PicoMemcard Project – PS1 Memory card made from a RPi Pico | RetroRGB
Sony Playstation 1 PS1 Official Memory Card Import SCPH-1020 from Japan tesed! | eBay
Amazon.com: Old Skool PS1 Memory Card for Sony PlayStation 1 (1mb) : Video Games