Once you've used heated gloves against the cold...... you won't forget them after that point. They're that good.
Mine are powered from the bike, rather than from battery powered, and last as long as the bike is running. The Hotwire design has a thermostat built into the outer surface and they adjust how much wattage they apply based on how fast the gloves cool. The heating elements are nanowire.... the gloves are no more bulky than any other cold/cool weather glove. Without power applied, I can ride in them to around 40F. There are only 3 output levels (low, medium, high) and I cannot use High unless it is below freezing at a standstill.