I suppose that could be a probalem but the sea isnt that cold. My w8 Peter swears he can get an extended life out of one by dipping it into the sea (when it starts to fade)every other cast or so.It may be you had been given a duffer, poss damaged in the shop and had been squashed and activated b4 you used it??I use sort of key ring light about the size of 2p coin It has a Led with 2 small flat3volt lithium batterys I just tape it onto the end of my rod just above the 2nd last ring its brill and you can switch it off.I would reccon 15/20 hours use they only cost a £1 from the poundshop (obviously) in Eldon Sqr just above the Green Mrkt.Thats if any are left (ask if not) they come and go.I got 10 for the 3 of us ,3colours red green and blue,not very waterproof but a few wraps of insulation tape soon sorts that out I swear the jets that fly over W/Bay beach at night think its Newcastle airports runway they seem to drop very fast and try to line up between our rod tips