How do you estimate a golf cart’s energy use per round to choose the right battery kWh?

Direct answer: Measure it rather than rely on range claims. Energy per round (kWh) is average pack power multiplied by driving time, or the sum of volts × amps × time from a logged round. Add a reserve and compare the result with the usable energy of the pack, which is less than the nominal figure.

Start with pack energy. Redway’s 48V 100Ah pack is listed at 5.12 kWh, the 48V 150Ah pack at 7.2 kWh and the 48V 200Ah short-size pack at 10.24 kWh. These are nominal energies (nominal voltage × rated Ah). You will not use all of it: the pages quote cycle life at 80% DOD, so plan on taking a stated share each day, for example 80% of nominal, and keep the rest as reserve.

Then measure one real round. Log pack voltage and current while a loaded cart drives your course, and note the state of charge at start and finish. A DC clamp meter works, and Redway lists Bluetooth and app monitoring as optional upgrades, so check what your model includes. Energy is the sum of V × I × Δt. Record passengers, bags, temperature and hills, since all of them change the result.

Here is illustrative arithmetic, not Redway data. If a logged round averaged 30A at 51V for 2.5 hours, that is 30 × 51 × 2.5 = 3,825 Wh, about 3.8 kWh. Two rounds in a day is about 7.7 kWh. Against 80% of a 7.2 kWh pack (5.76 kWh) that does not finish the day without a mid-day charge. Against 80% of a 10.24 kWh pack (about 8.2 kWh) it does, with roughly 0.5 kWh to spare.

Several factors move the number. Hills and hard acceleration raise average current, regenerative braking returns some energy on downhills, accessories such as lights, GPS and coolers add load, and cold weather and tyre pressure change consumption. Treat a logged figure as valid for that course and cart, and log again after a layout or fleet change.

Turn the result into a kWh line item in the quote and choose a pack with margin. Check charging too: the 48V 100Ah page lists a 22A standard charge (about 5 hours) and the 150Ah page 30A (about 5 hours). Confirm the charger and the pack’s current limits with Redway. The range figures on the product pages (for example 40–50 miles for 100Ah) come without test conditions, so use them only as a rough cross-check.