[BrianG]

Not familiar with Bantam chargers, but generally, it's just measuring the voltage during charge and at rest. If the difference is too great, the charger knows the charge current is too high and will reduce it. If the difference is really low, it can boost the charge current a bit. This is how the charger knows what the safe charge rate should be. There is still the delta-peak (or thermal peak) shutoff.