What Is The E-Z-GO ST-350 Gas Model Battery?

The E-Z-GO ST-350 gas model uses a 12V lead-acid battery primarily for ignition, lights, and accessories—not propulsion. Unlike electric golf carts, it employs a smaller automotive-style battery (Group U1 size, ~35Ah) designed for brief high-current bursts to start the engine. Regular maintenance includes terminal cleaning and voltage checks (≈12.6V when charged). RG72180 Battery Lithium upgrades (e.g., LiFePO4) are compatible but require voltage regulator adjustments to prevent alternator overload.

What battery does the E-Z-GO ST-350 gas model use?

This gas-powered cart relies on a 12V Group U1 battery with 35-40Ah capacity, similar to automotive starting batteries. Its primary role is engine ignition, not sustained energy delivery like electric cart packs.

Deep Dive: The ST-350’s 12V battery must deliver 200–300 cold cranking amps (CCA) to spin the 350cc engine reliably. Specifications include SAE terminal posts (top-mounted) and dimensions of 7.7″L x 5.1″W x 7.3″H. Pro Tip: Use AGM (absorbent glass mat) batteries here—they’re spill-proof and handle vibrations better than flooded lead-acid. For example, swapping to a 12V 40Ah AGM battery can extend service life from 2 to 4 years in bumpy terrain. Beyond the starter function, this battery also powers headlights and horns, so low voltage (<11.4V) may dim lights even if the engine starts.

How does the gas model battery differ from electric golf cart batteries?

Gas model batteries focus on short high-power bursts, while electric carts use deep-cycle batteries for prolonged discharge. Voltage also differs—12V vs. 36V/48V/72V systems.

Deep Dive: The ST-350’s 12V battery prioritizes cranking amps over capacity, whereas electric cart batteries (like 6V or 8V units) are designed for 50–80% depth-of-discharge cycles. Practically speaking, gas cart batteries idle at 12.6V but drop to 9–10V during engine cranking. In contrast, a 72V lithium pack for electric carts maintains steady voltage under load. Here’s a comparison:

Pro Tip: Electric cart batteries need monthly equalization charges, but gas model batteries thrive on occasional trickle charging (1A max). Ever wonder why gas batteries fail sooner? Their frequent shallow discharges accelerate sulfation compared to deep-cycle units.

What maintenance ensures longevity in ST-350 batteries?

Key practices include monthly voltage checks, terminal cleaning, and avoiding full discharges. AGM batteries require less upkeep than flooded types.

Deep Dive: Use a multimeter to test resting voltage monthly—12.4V means 75% charge; below 12V demands immediate charging. Terminals accumulate corrosion (white/green powder) from sulfuric acid vapors; scrub with baking soda solution and coat with dielectric grease. For flooded lead-acid batteries, check electrolyte levels every 3 months, topping up with distilled water if plates are exposed. Beyond the basics, store the cart with a battery maintainer in winter—self-discharge can drop voltage to 10.5V in -10°C, causing irreversible damage. Real-world example: A Florida golf course extended their ST-350 battery lifespan from 18 to 30 months by implementing biweekly terminal cleanings and using smart chargers.

How to replace an E-Z-GO ST-350 battery?

Disconnect negative first, remove hold-down clamps, swap batteries, then reconnect positive terminal last. Always wear gloves and eye protection.

Deep Dive: Start by turning off the cart and removing the key. Disconnect the negative (black) cable with an 8mm wrench to prevent short circuits. Lift out the old battery—it weighs 25–30 lbs, so use a lifting strap if needed. Install the new battery, securing it with the original hold-down bracket to minimize vibration damage. Reconnect positive (red) terminal first, then negative. Pro Tip: Apply anti-corrosion felt washers to both terminals—they’re soaked in acid-neutralizing compound. What happens if you reverse terminal order? Connecting positive first risks sparking if the wrench touches frame metal. After installation, test the ignition and lights to confirm proper operation.

Can you charge the ST-350 battery without removing it?

Yes, but use a 12V smart charger with desulfation mode. Avoid car chargers exceeding 10A to prevent overheating.

Deep Dive: Modern microprocessor-controlled chargers (e.g., NOCO Genius) safely charge in-place by adjusting amperage based on battery state. Set to “AGM” or “flooded” mode matching your battery type. Charging typically takes 4–6 hours from 12V to 14.4V (absorption phase), then drops to float (13.6V).

Real-world example: A New York dealership reduced battery replacements 60% by installing on-board 12V chargers that top up during storage. Remember, charging in a well-ventilated area is crucial—lead-acid batteries emit explosive hydrogen gas when charging.

Are lithium batteries viable for the ST-350 gas model?

Yes, 12V LiFePO4 batteries save 50% weight and last 3x longer but require a voltage regulator to handle the cart’s 15V+ charging system.

Deep Dive: Lithium batteries like a 12V 30Ah LiFePO4 unit weigh just 8 lbs vs. 30 lbs for lead-acid. However, gas carts’ voltage regulators (alternators) often push 15–16V when running, exceeding lithium’s 14.6V max. Solution: Install a DC-DC converter to clamp voltage to 14.4V. Pro Tip: Choose lithium batteries with built-in battery management systems (BMS)—they prevent overvoltage and balance cells. For example, a Texas fleet upgraded 50 ST-350s to lithium, cutting battery costs 40% over 5 years despite higher upfront prices. But why isn’t lithium plug-and-play here? Without voltage regulation, the alternator’s spikes can trigger BMS shutdowns mid-drive.

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