I've managed to kill a couple coin cell lights and my wife as well. The last one we bought was a princeton tech with fell apart in her purse, so spending $5-20 every couple years plus expensive coin cell batteries adds up to the price of the $29.99 Arc AAA in a very short time. I've standardized on AA and AAA in all my gear now and avoid anything with those coin cells, the cells just don't last more than a few months.