Replacing the old battery on rechargeable bike lights

Hello! Recently I needed bike lights for my bike. And I remembered that I already had rechargeable bike lights that I bought ten years ago, that I hadn't tried in a long time. I tried to recharge them, but after fully charging them, they only worked for maybe 5 minutes before they turned off again.

I don't know much about electronics, but I've been curious about whether it's possible to fix old electronics for a long time, and this seemed like the perfect repair project because I might just need to replace the battery.