Very often it's a battery problem. The easiest way to determine whether you have a charger problem is to test your charger on another cart, or test another cart's charger on your cart. We do understand that this is not always possible for most customers.

To find out for sure whether your batteries are the culprit, you’ll need a Digital Voltage Tester to test each individual battery. You’ll want to completely charge your golf cart before testing. While the charger is running, test your volts every 15 minutes. Whenever you see the same voltage back to back, that's how high your batteries' voltage will go and will give you an idea how good the batteries are. If you have a 36 volt system with 6 volt batteries, you’ll want to see readings of around 6.2 to 6.3 volts per battery (37.2 to 37.8 total volts). If you are showing something like a 4 volt charge on a 6 volt battery, you have a bad battery and will want to replace it. One bad battery can bring the performance of the entire set down. If you have a 48 volt system with 8 volt batteries, you’ll want to see readings of around 8.2 to 8.3 volts per battery (49.2 to 49.8 total volts). If you are showing something like a 6 volt charge on an 8 volt battery, you have a bad battery and will want to replace it.

Bad Batteries: IN GENERAL, if the charger doesn't kick on or show any signs of life when you plug it into your cart, this is most likely a battery/connection issue. 

Bad Charger: IN GENERAL, if the charger kicks on, but doesn't charge fully or kicks off soon after, this is likely a charger issue. If the charger makes a loud clicking noise, this is likely a battery charger issue. If the charger will not shut off or never stops charging, this is likely a battery charger issue as the internal "brain" is defective (unless you have a 48 volt Club Car).