+ what mitiempo said.
However, your alternator might be a problem. The four AGM golfcarts are capable of accepting very high amperage....at least 400 amps....for a substantial period of time.
The OEM alternator, probably with an internal regulator, isn't designed to put out high amperage for long periods. Typically, these are automotive alternators designed to put out high amperage for a very short period of time (minutes only) after which they ramp down considerably. Typical flooded lead-acid batteries will only take about 20% of their capacity in charging amps, while AGM's will accept well over 100%, and can overtax your alternator.
I see quite a few such mismatches, and burned out alternators as a result. If you're going to switch to AGMs and if you're going to cruise with them -- not sit at dockside with the charger plugged in -- then you'd be well advised to consider whether your engine's alternator is up to the task. If not, you'll need to go to a high-output alternator AND an external regulator.