Golfcar batteries last anywhere from 2 to 7 years depending on use and care. As batteries age, run time decreases. New batteries can easily accomadate 2 rounds of golf. Older batteries are significantly less efficient. If your cart can't do what you need it to, it is time for new batteries.
All automatic chargers require a minimum voltage to start a charge cycle. If the cart has been sitting for longer than four months, the batteries can self discharge to the point the voltage is too low to turn on the charger.
There are other reasons a cart won't charge, but this is the most common. In most cases a "jump start" will correct this problem. You should not need new batteries.
After 50 years in the battery/golfcar business, Trojan batteries have proven to be the most reliable and best value battery available. Trojan batteries are especially well suited to our desert environment, which makes them more resiliant to summer temperatures and seasonal use.
You get what you pay for. Golf car batteries are manufactured at two price points; Premium and Economy. A premium battery is heavier, has a higher plate count and more capacity than an economy battery. In general a premium will outlast an economy battery by two years.
Premium batteries are hands down a better value.
Read the fine print. In most cases your final cost will be much higher. Pick-up and delivery, installation, cables, hardware and tax will bring the price up considerably. Without exception you will be buying an economy battery. Always get a final estimate that is not to be exceeded and determined not just the brand but the exact battery to be installed. ALL MANUFACTURERS OFFER AN ECONOMY BATTERY.