The battery case has a tiny screw and I do not have a screwdriver to fit. However, if I did fit the battery, this gadget would still not work for me. I need a timer that will have alarms at the same times every day - not one that goes off at a set number of hours from now... I might as well carry a kitchen timer as this. The tablet compartment is also enormous. If I put my tablets in here they would rattle to powder in my bag. It has gone straight in the bin.
Having said that, I recognise that it may be perfect for people who want the timer function and take horse pills! But I wish them well with that battery compartment!