The KA600L is an improved model of the KA600, The solar panel on the KA600L is about 30% larger, it produces more current to drive the radio and trickle charge the battery. The Battery in KA600L is a 2200mah Lithium Battery, official model is 18650, it is much larger than the KA600 which is a 600 NI-Mh battery. Since the larger baattery installed on KA600L, we remove the AA battery from the KA600, but it lasts even longer after one fully charge with 18650. The AC adapter was take off the KA600 model, since the AC adapter produces not enough current to charge the 18650 battery, so you need to use any cellphone or computer USB port to change the 18650 battery,( On the KA600, there is USB port too).
The radio will remain the same on features , SW ,NOAA and AM/FM Plus RDS.
Anyway, you love KA600L after this improvement.
Please feel free to let me know if you have any questions.