Thats the charger I started with (and still have) it will not charge lipo, so if you have any intention of charging lipos, that charger will not. Other than that, its a good charger. Mine false peaked when pushed to the max 3.5amps (on AC) so you may have to reset and try charging again if it seems to quit early or your packs don't get warm.

Approx charge time - (mah/1000) / charge rate, amps = approx hours, example, 5000mah charging at 4amps - (5000/1000)/4 = 1.25hrs or 1hr 15min.
This is approx since it ignores what batt alreadu has in it when you start the charge and also ignores batts internal resistance.