Club Car 48V Runaway Charger??

[pharmsc]

I have a 1996 Club Car DS 48 volt that has a charging issue. The batteries are 20 months old. The cart is rarely used and it appears that my charger is cooking my batteries. I tested my batteries BEFORE charging today and the resting voltage across the pack was 52.2 volts. Upon hooking up the charger it drew 13 amps for a couple of minutes then settled down to 6 amps. I checked approximately 45 minutes after charging began and the voltage across the pack WITH THE CHARGER ON and was showing 59.7 Volts and was still charging at 4 amps!
I then disconnected the charger and let the pack rest for a few minutes and the voltage across the pack WITH THE CHARGER OFF was 55.7 volts!! I rechecked the resting voltage on the pack 3 hours later and show 53 volts across the pack. All of the batteries are within 0.1 volts of each other and all connections are clean and tight on battery terminals.

What should the charging voltage and the resting voltage be? The batteries are gassing and in the past if the charger is left on for a long time the batteries gas really hard.! The batteries are using a good bit of water.
How do I test the charger for proper operation

Please give me some insight. I really appreciate the help. Any diagrams or testing algorithms appreciated. Thanks Bob T