A few things to think about: Better chargers usually come in a metal case and are fan cooled. They come in different amperages which determines how fast your battery charges. Charging too fast at too high of an amperage can shorten the life of your battery.
This is why Tesla recommends that their cars not be charged at their super chargers very often. They are intended for fast charges on road trips with routine daily charges taking place at a slower charger at home or in a parking lot.
Electrify bike chargers come in 2 amp or fast charge 4 amp sizes. 4 amp chargers charge twice as fast as 2 amp. A 52v 700 watt hour battery will charge in 3.5 hours with a 4 amp charger if it is fully drained. The same battery will charge in 7 hours with a 2 amp charger. All of the batteries sold by Electrify Bike including the mini-cubes can take a 4 amp charge without any negative impact on battery life.
Increasing the number of charge cycles: A smart charger can increase the number of charge cycles of your battery dramatically. If you charge your battery to 100% every time, it will take about 400 charge cycles before the battery capacity is reduced to 85%. This is 2 charges a week for 4 years. Not bad! You may want a new battery in four years anyway. However, if you have a long commute and charge everyday you will exhaust your 400 charges in just over a year. Did you know that if you only charge your battery to 90% you can get close to 1000 charges? Or if you charge it to only 80% you will get closer to 2000 charges? This is true of all lithium ion batteries including your cell phone. The problem is everyone is competing on talk time so they always max the charge to 100% instead of optimizing for battery life.
A smart charger is has a selectable amount of charge. For example, Electrify Bike's smart charger have a rotary switch that is selectable for 80%, 90% and 100% charges. We recommend charging to 90% unless you are planning a long ride. For long rides top it off to 100%. The occasional 100% won't have a big impact on battery life.