The E-Z-GO Voltage Regulator is one of the essential parts of the golf cart. You have to have a fully charged battery to get the caddie started. The battery powers the starter generator, which electrically turns the crankshaft to produce a spark at the plug. When the engine starts, the starter becomes a generator and starts recharging the battery, but it needs help. If left unchecked, the generator would charge the battery at 18-20 volts. For a little 1-volt battery, that is way too much. It could melt posts or even blow up cells. If you have never been sitting on an EZGO seat when a battery exploded, count yourself lucky because it will put you through the windshield.The golf cart voltage regulator pulls down that recharge voltage to a safe range of 13.5-15.5 volts allowing your battery to stay charged the entire time you use it. Now, if it remains parked for a long time, this will not help; take a look at the trickle chargers here at Buggies Unlimited to fix that issue.