A cheap digital multimeter is enough to see whether a golf cart pack is 36V or 48V and whether one battery has fallen behind the others. This is a resting-voltage check, not a load test. A battery can read fine at rest and still fall over when you climb a hill.
Read one battery
Fully charge the cart, unplug the charger, and let the pack sit for a few hours. Set the meter to DC volts. Touch the red lead to the positive post and the black lead to the negative post of one battery. A healthy flooded 6V battery rests around 6.3 volts. A healthy 8V battery rests around 8.4 volts. A 12V golf battery rests around 12.6 volts. A battery that sits a full volt under its neighbors is the one dragging the pack.
Read the whole pack
Measure from the main positive cable to the main negative cable. Six 6V batteries in series rest near 38 volts. That is a 36V cart. Six 8V batteries, or eight 6V batteries, rest near 50 volts. That is a 48V cart. A tired 48V pack can still read in the mid-40s. A 36V pack does not.
Write the numbers down. If two or more batteries are low, replace the set. Mixing one new battery into an old pack makes the new battery do all the work. Send us the readings and a photo of one label if you want a set matched to the cart.
