Choose a golf cart voltage reducer with an output-current rating at least as high as the combined current draw of the accessories that may run at the same time. Calculate each accessory’s amps at the reducer’s output voltage, then add those amps; accessories used at different times do not need to be added as simultaneous loads.
Calculate each accessory’s current
For a DC accessory, divide its power in watts by the reducer’s output voltage in volts: I = P ÷ V. The Department of Energy’s circuit explanation gives the relationship between power, current, and voltage. If the accessory’s current is already specified at the reducer’s output voltage, use that current directly.
Use the accessory’s stated power or current and the reducer’s output voltage. For example, suppose three accessories each use 120 W at 12 V and may operate together. Each draws 120 W ÷ 12 V = 10 A, so their combined load is 10 A + 10 A + 10 A = 30 A. The reducer’s output-current rating should therefore be at least 30 A for this example.
For AC loads, the same division applies to average real power when using RMS voltage and current. Do not apply the DC calculation to an AC load using incompatible power or voltage values.
Add only loads that can run together
List the accessories that may be switched on at the same time, calculate or look up each one’s current at the reducer’s output voltage, and add those values. If two accessories are used only at separate times, include the larger applicable simultaneous combination rather than adding both as though they run together.
The result is the accessory load in amps. Compare it with the reducer’s output-current rating; there is no single amp rating that fits every cart, because the answer depends on the accessories and which ones operate simultaneously.
FAQs
How do I calculate the amps an accessory needs from its wattage?
Divide the accessory’s power in watts by the reducer’s output voltage in volts: amps = watts ÷ volts. For example, a 120 W accessory operating at 12 V draws 10 A.
Should I add the amps of every golf cart accessory together?
Add the current draws of accessories that may operate at the same time. For accessories used only at separate times, use the largest applicable simultaneous combination rather than adding all their currents together.
