"Good condition batteries" is subjective.
How old are they and how have they been maintained is the key.
Do you know their history?
Got a meter? Post up some pack voltage after full charging and resting 12hrs.
Also under load, like going up a moderate incline, what are the voltages on each battery?
Just clip meter on a battery and set meter on seat and drive and get volts.
Move leads to the next battery and so on. May need longer leads and larger clips.
Post up the results and we can see what you have going on.
What charger do you have?
This thread is helpful. Especially the state of charge charts.
http://www.buggiesgonewild.com/elect...batteries.html