What does this mean in datasheet : 2k: Ipgm/10 for term; Ipgm/5 for precharge
When charging, the charging is terminated when charging current has dropped to I/10, i.e. the battery is full.

When battery is really low on charge, it is slowly charged at I/5 before it is safe to charge it with full current.

These are achieved with 2k resistor.