Dual fast charger for all DeWalt Li-Ion XR slide batteries of 10.8, 14.4, and 18 volts, ranging from 1.3 to 5.0 Ah, as well as for DeWalt Flexvolt batteries (54 or 18 volts with a maximum of 9.0 Ah). It allows for the simultaneous charging of two batteries of different voltage and Ah classes without any issues. The 2-stage charging process ensures a gentle charging of the batteries, resulting in a high number of charge cycles at maximum storage capacity.