Predator 3500 Inverter
Harbor Freight's cult favorite for RV air conditioners.
Specs
| Running watts | 3,000 W |
| Starting watts | 3,500 W |
| Type | Inverter |
| Fuel | Gasoline |
| Weight | 99.2 lb |
| Noise (mfr figure) | 57 dBA |
| Fuel tank | 2.6 gal |
| Runtime (mfr claim) | ~11 h at 25% load |
| Outlets | Two 20A 125V, TT-30R (RV) |
| Start | Electric |
| Parallel capable | No |
| CO safety shutoff | Varies by version — check the listing |
| Typical street price | ~$900 (fluctuates — check listing) |
Figures are the manufacturer's published specs; dashes mean the maker doesn't publish a number. Verify against the current datasheet before you buy.
What can it actually run?
Checked with the same math as our calculator: total running watts, plus the single largest motor surge on top. “Tight” means it technically fits but the load sits above 80% of rated output — fine briefly, not where you want to live.
- ✓ runs itFridge, Wi-Fi, and lights730 W running · 2,230 W peak
- ✗ too muchStorm essentials (fridge, freezer, furnace fan, sump pump)3,080 W running · 4,630 W peak
- ✗ too muchEssentials plus a 10,000 BTU window AC4,280 W running · 6,680 W peak
- ✗ too muchMost of the house (well pump, central AC, laundry)13,680 W running · 19,680 W peak
The installer's take
The RV crowd adopted this thing en masse because it starts a 13,500 BTU rooftop AC, runs quiet enough for a campground, and Harbor Freight coupons used to make it absurdly cheap. It's heavy for its class and the warranty path is 'bring it back to the store,' but the track record across thousands of RV forum owners is genuinely good. Buy the wheel kit — at 99 lb you're not carrying it far.
Pros
- Starts a 13.5k BTU RV air conditioner
- 57 dBA — campground-friendly
- Electric start standard
Cons
- Heavy for a 'portable' inverter
- Store-return warranty rather than a service network
- Not parallel-capable