Batteries are rated at a discharge measured in C - which is easy to understand once explained reasonably well - which I will try to do.
The C stands for "capacity" - the total charge of a battery. So for simplicity we will choose a 1000mah battery. In it's simplest terms, that means that this battery can supply 1 amp for one hour constantly before it is discharged. If you only pull .5 amp, then it would last two hours. The C rating governs what can safely (for the battery) be discharged over a period of time. So if a battery says that it can handle a .5C discharge - then it can in our example only handle .5amp costant discharge for two hours.
Now most batteries can burst safely above the constant C - so say 1C for 15 seconds - anything above this will start to decrease the life of the battery. What makes things harder to measure, is that they have a rest cycle for the safe burst C rating - which can vary as widely as the batteries themselves.
So all of that to say - if your battery is a 1000mah, and the cart is pulling say 2amps, then that is a 2c discharge rate. If your batt is not rated for that, it will work more than likely, but each time it is decreasing the overall capacity and life of the battery.
Hopefully that helps and makes sense
