The worst calls I ever ran as an electrician came the morning after a storm. Not because the generator broke, but because nobody had touched it since the last outage. A homeowner would call, frantic, and I’d show up to find a machine that hadn’t been started in eight months, sitting on a bone-dry battery with fuel that had turned to varnish.
None of that had to happen. The fixes take an afternoon, and most of them cost nothing but your time. A little generator storm preparation goes a long way toward the difference between a warm house and a very long, dark night.
So here’s the routine I walked every one of my regular customers through before hurricane season or the first hard freeze. Work it top to bottom.
Key takeaways
- Test-run your generator under load before the storm, not during it, and confirm the battery holds a charge.
- Never run any generator inside a garage, breezeway, or within 20 feet of a window. Carbon monoxide kills fast and silent.
- Stabilized fuel, a topped-off tank, fresh oil, and a clear intake handle roughly 90% of storm-night failures.
Start It Before You Need It
A generator that sits idle is a generator you can’t trust. The single most useful thing you can do is start the unit a week out and let it run 20 to 30 minutes under some real load, not just idling with nothing plugged in.
On a job last winter, a customer swore his standby unit was fine because it “clicked on” every Wednesday for its self-test. Problem was, that weekly exercise cycle runs for maybe 12 minutes with no load. When the actual outage hit, the transfer switch engaged, the engine bogged under the house load, and it stalled. The self-test never proved it could carry weight.
Run the real thing. For portable units, plug in a couple of space heaters or a shop vac and let it work. If you want the full rhythm on how often to fire it up between storms, I laid that out in a piece on how often you should exercise a standby generator.
Never test or run a generator in an attached garage, even with the door open. A running engine can push carbon monoxide levels lethal in minutes. Keep it outside, at least 20 feet from the house, with the exhaust aimed away from doors and windows.
Check the Fuel Situation Early
Fuel is where I saw the most preventable failures. Gasoline starts breaking down in about 30 days, and by three months the old stuff can gum a carburetor solid. If your portable has been sitting since spring, that fuel is suspect.
Drain it or run it dry, then refill with fresh gas treated with a stabilizer. A bottle of stabilizer runs about $10 and treats dozens of gallons.
How Much to Store
A mid-size portable burns roughly 12 to 18 gallons of gasoline per day at half load. Plan for that. Storing three to five gallons in an approved container gets most homes through the first 24 hours, but you know your outage history better than I do.
Propane and natural gas dodge the staleness problem entirely, which is a big reason I steered a lot of clients toward them. If you’re weighing options, I compared the tradeoffs in a breakdown of the common generator fuel types.
- Fuel is fresh or freshly stabilized (under 30 days old)
- Tank topped off; extra fuel in approved, sealed containers
- Propane tanks checked for level and valve function
- Fuel stored outside, away from living spaces and heat
Oil, Filters, and the Boring Stuff That Matters
Pull the dipstick. Low or black, gritty oil under storm load is how engines seize. If you’re near the service interval, change it now. On most portables that’s a quart of oil, a $5 filter, and 20 minutes.
Check the air filter too. A clogged filter chokes the engine and drops your usable wattage right when you need every watt. These are small chores, but they stack up. My full rundown lives in the complete generator maintenance checklist if you want the whole sequence.
The Battery Is the Part Everyone Forgets
Standby generators start on a battery, same as your car. And like a car battery, it dies quietly. I’d guess half the no-start calls I ran traced back to a dead or corroded battery, not the engine.
Check the terminals for that white, crusty buildup and clean it off. If the battery is more than three years old, load-test it or just replace it. A new one runs $40 to $120 and beats sitting in the dark.
Cold weather makes it worse, since a battery loses a chunk of its cranking power below freezing. I walked through testing and replacement in detail in a guide on generator battery maintenance and replacement.
Keep a battery tender on standby units that don’t run often. A $30 trickle charger keeps the starting battery healthy year-round and has saved more of my customers than any single tool I carried.
Clear the Air and Check the Connection
Give the generator three to four feet of clearance on every side and above. Snow drifts, leaf piles, and stacked firewood block the airflow the engine needs to cool, and a covered exhaust is a carbon monoxide trap.
If you power your house through a transfer switch, test that it actually flips. A surprising number of people have never watched their switch operate. If you’re fuzzy on how yours works, the guide to transfer switches covers it plainly.
And if you’re running a portable in cold months, protect it from the elements the right way. Freezing rain and a running engine don’t mix, so read up on winterizing a portable generator before the temperature drops.
A Quick Reference for Storm Day
| Check | Why it matters | Time |
|---|---|---|
| Load test run | Proves it carries real weight | 30 min |
| Fuel fresh + stored | Prevents gummed carburetor | 15 min |
| Oil + air filter | Stops engine damage | 20 min |
| Battery + terminals | Ends most no-start calls | 10 min |
| Clearances + exhaust | CO safety and cooling | 10 min |
The whole list takes under two hours. Carbon monoxide is the one item where “close enough” gets people killed, so read the CPSC’s portable generator safety guidance and put a battery-powered CO alarm in the house. The federal power outage checklist at Ready.gov is also worth a five-minute read the week before season starts.
Your Move Before the Next Front Rolls In
Pick a calm Saturday and run the list once, start to finish. You’ll learn exactly what your generator does, what it doesn’t, and where the weak link is, all while the sun is out and the hardware store is open.
Do it once and the second time takes 40 minutes. That’s the whole trick. The people who never lose power aren’t lucky. They just did the boring work before the wind picked up.
