Hence, if your batteries are rated 2500mAh and they are fully depleted, it will take 2.5 hours to completely charge the batteries at rapid charge mode.
For me, I normally use the gentle charge mode, hence the charging time will take longer.
After twice encounter with MH-C401FS (my friend had similiar problems) that melted my batteries, the one with can charge more batteries seems to be the best choice for now.