What are the differences between standard, rapid, and sensing (“smart”) chargers?

The primary differences between standard, rapid, and smart chargers are their charging speed, overcharge protection mechanisms, and advanced battery management capabilities. A Standard charger is considered to be a slow / overnight charger, typically taking up to 12 hours, and continues to charge even after full, which can shorten battery life. A Rapid charger charges your battery typically in 1 to 3 hours and switches to a trickle charge mode to prevent overcharging. Smart chargers also charge rapidly (1 to 3 hours) but additionally discharge, analyze, condition, and perform cycle tests on your batteries, often doubling their lifespan.