What do the different charging modes on the C3 mean, and which one should I use?

Mode 1 is for 6 V batteries under 14 Ah (WET/GEL), Mode 2 is for 12 V batteries under 14 Ah (WET/GEL, motorcycle), Mode 3 is for 12 V batteries over 14 Ah in normal state (WET/GEL), and Mode 4 is for 12 V batteries over 14 Ah in cold state or for AGM batteries. Select the appropriate mode by pressing the mode selection button (8) until the correct LED lights up. Charging starts automatically after a few seconds. (Page 6)