I have accidentally left my Spark3 in my jui-jitsu bag after class, forgetting to put it back on. I find it the next day, alarm still going off 6 hours later, battery drained to almost empty. It would be very helpful if the device had an auto shut off feature. Stop "alarming" after maybe 15 minutes. Is this a known issue and can you add it to the list of items to improve on?