A Generator Buyer's 7-Step Checklist (What I Learned After $12K in Rework)

Who This Checklist Is For

If you're an office manager or facilities coordinator tasked with purchasing a standby generator for your building—and you're not an electrician—this is for you. I manage all service and equipment ordering for a 130-person company across three locations, roughly $45K annually across 8 vendors. After 5 years in this role, I've learned the hard way that the wrong generator spec can cost you weeks of delays and thousands in change orders.

Below are the 7 steps I now run through before placing an order. They won't make you an expert, but they'll keep you from making the same mistakes I did.

Step 1: Confirm the Fuel Type and Tank Capacity

Most buyers focus on the generator wattage and completely miss whether the fuel source is actually available on site or compatible with existing infrastructure.

For a Briggs & Stratton home generator, you typically have three fuel paths: natural gas (if piped in), propane (liquid or vapor), or diesel. The question everyone asks is, "how many watts?" The question they should ask is, "what's the fuel tank capacity and how long will it run under load?"

I assumed a standard 100-gallon propane tank would run a 20kW unit for 3 days. Turns out—under full load—we were looking at maybe 36 hours. I had to source a secondary tank at the last minute, which ate a weekend and added $700 in rental fees.

Step 2: Verify the Air Filter Specification (Don't Skip This)

What is an air filter in a car? Most people know it's the thing that keeps debris out of the engine intake. The same concept applies to generators. A generator air filter needs to match the engine model exactly. A mismatch here can cause the unit to run rich, burn oil, or fail to start under load.

Like most beginners, I assumed "it's just a filter—they're all the same size." Learned that lesson when a replacement filter didn't seat properly and the unit threw a fault code during a scheduled test. The service call and part cost nearly $250. Now I check the Briggs & Stratton OEM parts catalog for the exact filter part number before ordering anything.

Step 3: Plan for Battery Charging and Maintenance

A standby generator sits idle for weeks or months. That means the battery can drain. If the battery is dead, the generator won't start when you need it. This is where a battery tender 4 amp battery charger and maintainer becomes essential. It's a small investment (typically $25–$40) that prevents a $200+ service call for a jump start.

Here's the thing: not all chargers are compatible with the generator's battery type (AGM, flooded, lithium). I learned this when the sony battery charger I grabbed from the camera closet obviously didn't fit—yes, that was a dumb moment. The correct charger needs to match the battery chemistry and voltage. Most standby generators use a 12V AGM battery, so get a maintainer rated for that.

Step 4: Double-Check the Fuel Tank Location and Piping

The Briggs and Stratton generator fuel tank is sometimes integrated into the unit, but larger standby models often require a remote tank. The location affects installation cost significantly. A tank placed 50 feet away from the generator requires longer fuel lines, more labor, and possibly a fuel pump.

To be fair, the sales rep did mention "proximity matters." What I didn't realize is that running a fuel line under a concrete driveway costs about $15–$20 per linear foot. We ended up rerouting the install because the original spot was too far from the tank connection.

Step 5: Verify Transfer Switch Compatibility

This is the part most non-electricians forget. The generator needs to connect to your building's electrical system through a transfer switch. Not all generators work with all switches. If you're buying a Briggs and Stratton home generator, confirm whether it comes with a bundled transfer switch or requires a specific model.

Why does this matter? Because using the wrong transfer switch can create a safety hazard and void your warranty. The installation contractor should verify this, but don't leave it all to them—I had a vendor order a switch that wasn't rated for the generator's surge current, which meant we couldn't power the HVAC system. That cost us a full day of rework.

Step 6: Set Up a Scheduled Maintenance Log

Once the generator is installed, the real work begins. A generator is a machine that needs regular care. The most frustrating part of post-installation: no one remembers to check the oil, filter, and battery every month. You'd think a machine that only runs a few hours a year would stay clean, but moisture, dust, and rodents cause surprising damage.

I created a simple 4-point monthly checklist after our generator failed a self-test because the battery tender wasn't plugged in. The item log is posted on the wall next to the control panel. It takes 5 minutes. It has saved us about $800 in potential service fees.

Step 7: Keep Spare Parts Handy

When a component fails during a power outage, you won't have time to order it and wait for delivery. I keep one set of the most common replacement parts on the shelf: an air filter, a spark plug, an oil filter, and a fuse set. Having a spare Briggs and Stratton generator fuel tank isn't practical unless you have a large facility, but a can of approved fuel stabilizer and a spare battery tender are cheap.

Dodged a bullet last winter when the primary generator wouldn't start due to a clogged air filter. I had the replacement in hand. If I'd waited for delivery, the building would have gone dark for two days.

"5 minutes of verification beats 5 days of correction." — The rule I now follow for any equipment order.

Common Mistakes to Avoid

• Assuming fuel capacity = runtime. Always calculate runtime at 50% and 100% load. Use the manufacturer's consumption rates.
• Ignoring battery charging. A generator without a charged battery is just a heavy paperweight. Get a maintainer that matches the battery type.
• Not verifying parts compatibility. Check the exact OEM part numbers. Don't assume "fits Briggs & Stratton" without confirming the series.
• Skipping the monthly check. The self-test feature only works if the battery is good. Walk the unit once a month.

Look, I'm not saying this list is exhaustive. But following these steps will keep you from making the same expensive, time-consuming errors I did. A generator is a long-term asset—treat the upfront spec work with the same care as the installation.