Charged up my PSP 1000 today, which is still on it’s original battery. Somehow it’s still going, with no swelling or visible issues.
Have left it on the Ratchet and Clank title screen (running from SD card) just to see what it’s got in the tank, and it’s still trundling on after 2 and a half hours. It’s a good showing given that this battery is an ancient relic.
Had been all set to rip out the UMD and buy a taobao extended battery mod, but it’s just not needed right now. Will see how many more years this battery gives, but it’s like DS Lite levels of battery quality.
Edit: 3:58.20 and it finally popped up the battery low light and went into standby. Great effort.