Led lights, press button one and blinks for 15 seconds, press button twice fast and blink for 15 minutes, press again and turns off

Supposed to have 12 hours of life, and even that package reads batteries are non replaceable, you can pop them open with an small knife and just replace the batteries 2x L1131 they are very cheap you can buy 10 on eBay for $2 so you can reuse the pins again and again

Some of the edges might show some separation 

Thanks