How Should a Portable Generator Be Prepared for Long-Term Storage?

When the power goes out, a portable generator can be a lifesaver. But what happens when you don’t need it for weeks—or even months? If you’re shopping for a generator to prepare your home for emergencies, it’s equally important to ask: How should a portable generator be prepared for long-term storage?

The short answer: To store a portable generator safely and ensure it’s ready when the next outage hits, you’ll need to drain or stabilize the fuel, disconnect or maintain the battery, clean and inspect the unit, and store it in a dry, secure, and well-ventilated space. Improper storage can lead to fuel degradation, corrosion, battery failure, or even engine damage.

This article will walk you through a complete, step-by-step guide for preparing your generator for long-term storage—including expert maintenance tips, safety precautions, and key accessories that help preserve performance.

Why Proper Generator Storage Matters

Even if your generator only runs a few times a year, its internal systems—especially the fuel system and engine—can degrade quickly if not stored correctly. Left unchecked, you could be facing:

⚠️ Gummed-up carburetors from stale gasoline
⚠️ Dead or sulfated batteries
⚠️ Rust and corrosion inside the tank or engine block
⚠️ Difficulty starting during a power emergency

Proper storage preserves the lifespan of your investment and ensures that it runs reliably when you need it most.

When to Prepare a Generator for Long-Term Storage

If your generator will sit unused for more than 30 days, it’s best to prepare it for long-term storage. This applies whether you store it seasonally (after hurricane or winter storm season) or use it solely for rare blackouts.

Examples of long-term storage scenarios:

🏠 Emergency-only home generators used 1–2 times per year
🌪️ Seasonal use during storm seasons or wildfire outages
🏕️ Portable units used for camping or RVing in summer only

Step-by-Step: How to Store a Portable Generator Long-Term

Step 1: 🧪 Treat or Drain the Fuel

Gasoline begins to degrade in as little as 30 days. It oxidizes, gums up internal parts, and causes engine-start failures.

Option A: Add Fuel Stabilizer

Fill the tank with fresh fuel
Add a high-quality fuel stabilizer (e.g., STA-BIL Storage or Sea Foam)
Run the generator for 10–15 minutes to circulate stabilized fuel through the carburetor

Option B: Drain the Fuel Completely

Turn off the fuel valve
Run the generator dry until it stalls
Empty the gas tank using a siphon or drain valve
Drain the carburetor bowl (if accessible)

💡 Tip: If you don’t use stabilized fuel, always drain it before storing your generator for more than 30 days.

Step 2: 🧹 Clean the Generator

Wipe down the exterior with a clean rag to remove dust, grime, and fuel residue
Blow out debris from vents and air filters using compressed air
Inspect for oil leaks, corrosion, or damaged components

Step 3: 🔋 Maintain or Disconnect the Battery (If Applicable)

Many inverter and electric-start generators have internal batteries that will discharge over time.

Disconnect the negative battery terminal to prevent phantom drain
Use a trickle charger or battery maintainer to keep the battery topped off
Store the battery indoors in cold climates to prevent freezing

Step 4: 🛢️ Change the Oil and Check Fluids

Used oil can contain acids and contaminants that corrode internal engine parts during storage.

Run the generator for 5 minutes to warm the oil
Drain old oil and replace it with fresh oil (follow owner’s manual spec)
Check and top off air filter, spark plug, and coolant (if applicable)

Step 5: 🧯 Store in a Safe, Dry Location

Proper generator storage location is essential for safety and longevity:

Store in a cool, dry, and well-ventilated space
Keep away from flammable materials and heat sources
Place on a pallet or platform to avoid direct contact with concrete (which can retain moisture)
Use a breathable generator cover to protect from dust, rodents, and corrosion—avoid airtight plastic tarps

Step 6: 🗓️ Schedule Maintenance Reminders

Set calendar alerts every 3–6 months to:

Start and run the generator for 10–15 minutes
Recharge or rotate the battery
Check fuel or oil levels

💡 Pro Tip: Always store with the generator’s instruction manual and maintenance log for quick reference.

Special Considerations by Generator Type

Generator Type	Fuel	Key Storage Tips
Gasoline Portable Generator	Gasoline	Drain or stabilize fuel, change oil, protect from fumes
Dual Fuel Generator	Gasoline + Propane	Disconnect propane tank, drain gasoline, check fuel lines
Inverter Generator	Gasoline	Maintain battery if electric start, stabilize fuel, clean air filter
Solar Generator (Battery-Based)	Electric	Store indoors, recharge every 3–6 months, avoid full discharge

Accessories That Help With Long-Term Storage

Fuel Stabilizer: STA-BIL, Sea Foam, or PRI-G extend gasoline life up to 24 months
Generator Cover: Breathable, water-resistant cover prevents rust and rodent damage
Trickle Charger: Keep batteries topped off to prevent sulfation or failure
Maintenance Kit: Keep oil, air filters, spark plugs, and wrenches on hand for seasonal checkups

Restarting a Generator After Long-Term Storage

Before using your stored generator during the next emergency:

🔍 Inspect for fuel leaks, rodents, and signs of corrosion
🛢️ Check and top off oil, fuel, and battery charge
🧪 If fuel is more than 6 months old, drain and replace it
🚀 Run the generator for 15–20 minutes with a small load to ensure everything works correctly

If you notice sputtering, poor startup, or inconsistent power output, consider cleaning the carburetor or contacting a certified technician.

FAQs: Storing a Portable Generator Long-Term

Q: Can I leave fuel in my generator during storage?

Only if it’s treated with a fuel stabilizer and stored in a cool, dry location. Otherwise, drain it to prevent gumming.

Q: Should I run the generator dry before storing it?

Yes. Running the engine until it stalls helps empty the carburetor and prevent clogging from fuel residue.

Q: How often should I start my generator during storage?

Every 3 to 6 months, start it and let it run for at least 10 minutes with a small load. This keeps components lubricated and ensures a ready start.

Q: Can I store my generator in the garage?

Yes, but ensure the fuel tank is tightly sealed, the space is ventilated, and the generator is cool before storage. Never store next to water heaters or flame-producing appliances.

Q: What’s the best way to store generator fuel?

Use approved gas cans, treat the fuel with stabilizer, and keep it in a cool, detached structure like a shed. Rotate fuel every 6–12 months.

Conclusion: Proper Generator Storage Ensures Long-Term Reliability

A portable generator is one of the most important tools for home emergency preparedness—but it won’t do you any good if it won’t start when you need it. By following these long-term storage tips, you’ll protect your investment, avoid costly repairs, and ensure your generator is always ready for the next outage.

Drain or stabilize the fuel, maintain your battery, clean and inspect key components, and store your unit in a safe, dry location. A few extra steps now will give you confidence and peace of mind during the next storm or blackout.