Congratulations on the Empulse!
It is helpful to leave the bike plugged in after it reaches 100% because that extras time spent on the charger balances the small differences among the batteries. If you press both buttons on the dashboard simultaneously, you'll see some numbers showing the battery with the highest voltage and the battery with the lowest voltage. After the state of charge indicator shows 100%, the rest of the time is spent bringing the low batteries up to the level of the other batteries, if possible.
Press both buttons on the dashboard simultaneously again to return to the normal dashboard display board mode.