Golf cart batteries: flooded, AGM or lithium
A cart pack is the single most expensive wear item a cart owner faces, and the choice is genuinely different from a car battery. Golf carts draw steadily for an hour or more, then get charged hard. That is a deep-cycle job, not a starting job.
What a factory cart actually uses
Most 48V carts run on either six 8V flooded cells (48V nominal, often 150-170Ah at the 20-hour rate) or four 12V batteries of the same nominal voltage. Thirty-six volt carts use six 6V cells. Flooded lead-acid is cheap per amp-hour, tolerates overcharging better than AGM, and wants water checks every few weeks in hot climates.
Rule of thumb: a healthy flooded pack delivers roughly 45-55 minutes of hard driving, or two to four hours of stop-start play. When range halves, the pack is usually past 60% of its original capacity and heading for replacement.
Cost per usable kilowatt-hour, which is the honest comparison
| Option | Typical pack cost | Usable depth of discharge | Realistic cycles | Cost per usable kWh over life |
|---|---|---|---|---|
| Flooded lead-acid (6 × 8V) | $600-1,100 | 50% | 300-500 | Highest cost per cycle |
| AGM (sealed) | $900-1,600 | 50-60% | 400-700 | Similar to flooded, less maintenance |
| LiFePO4 48V (single pack) | $1,500-2,600 | 80-90% | 3,000-5,000 | Lowest over 4+ years of regular use |
The arithmetic is unforgiving in one direction: if you plan to keep the cart five years and drive it most weeks, lithium usually wins despite costing double. If the cart gets occasional weekend use, a flooded pack is the better financial decision and the extra maintenance is trivial.
Four things that decide it
1. Heat
Lead-acid life roughly halves for every 15°F above 77°F. In Florida, south Texas or Arizona, an unshaded cart on a driveway can bake a flooded pack to three years. Lithium cells tolerate heat better but the BMS will throttle charging when hot, and most brands limit charging below freezing outright.
2. Weight
A flooded 48V pack weighs 350-420 lb. A lithium replacement is often 90-130 lb. Removing 250 lb changes acceleration, braking distance and turf damage — and on a lifted cart, it can alter handling enough to need suspension adjustment.
3. Your charger
Lithium requires a charger with a lithium profile or a BMS-controlled charger. Putting a lithium pack onto a 20-year-old ferro-resonant golf cart charger is how packs die early — and how warranties are voided.
4. Voltage display
Flooded packs sag under load, so the dash gauge is a poor state-of-charge indicator. Lithium packs hold voltage flat until nearly empty, so a 48V lithium pack reads "full" until it very nearly isn't. A shunt-based meter is worth the $60 on lithium.
When to replace versus recondition
Reconditioning (desulfation) occasionally recovers a pack that was left flat for months, and almost never restores a pack that has simply cycled out. Do a proper test first: charge fully, rest an hour, record the voltage, then run a known load and time the discharge. If the pack falls to 80% of rated amp-hours, plan replacement rather than chasing additives.