Tell us....
Does your new charger temperature compensate and your old one doesn't? And was it on the chilly side when you charged with the 4A charger?
That would explain the cutoff difference; at around 10deg. Celsius, a boost charge of 29.8V sounds correct...
Edit;
If it was a while since you charged the batteries before your trip that drew 140Wh, the self-discharge could also explain some of the difference...
Besides; charging FLA's are not 100% efficient...