Depending on the quality of your power supply you might have trouble with false peaks if the chargers pull power in pulses. Even if your power supply is rated @ 10Amps and works fine at 8 amps or so with a single charger it might well have trouble with two set at 8 amps total.
Try it out but keep an eye on the peak point and see whether the cells are taking the same amount of mah as with a single charger on the PSU.
You could also try with a large capacitor with a charging circuit like the ones used for car stereos but that alone would probably cost more than a second PSU
