Short answer: most mobile pet grooming rigs need 7 to 10 kW of generator capacity. Coffee-and-bath-only operations get by on 5 kW. Trucks running a high-velocity dryer plus dual A/C plus tankless water heater need 10 kW. The dryer is the biggest single load. Sizing wrong here means tripping breakers mid-service, which kills your day. Here is the actual math, the equipment that pulls the most, and how we spec generators on every build.
The math nobody walks you through
Pet mobile generator sizing is fundamentally about three things running together: the dryer, the A/C, and the water heater. Plus refrigeration and lighting in the background. Total continuous load on a busy summer day with a 60-pound mixed-coat dog being dried while the A/C is fighting 95F outside:
| Equipment | Running watts | Surge watts |
|---|---|---|
| High-velocity dryer (K-9 II or Edemco) | 1,400-1,800 | 2,200-2,800 |
| Rooftop A/C unit (13.5K BTU) | 1,400 | 3,000 |
| Second rooftop A/C unit | 1,400 | 3,000 |
| Tankless gas water heater (electric ignition) | 100 | 300 |
| Water pump (12V via converter) | 100 | 300 |
| LED interior lighting | 150 | 150 |
| Hydraulic tub pump (intermittent) | 300 | 800 |
| POS tablet, receipt printer | 100 | 100 |
| Vacuum / hair containment system | 600 | 1,400 |
Add up everything running concurrently during a hot summer dry: dryer + 2 A/C + water heater + lights + pump + POS = roughly 4,650 watts continuous. Surge during compressor cycle plus dryer start: spike to 7,000+ watts.
That math says you need a generator with 5,000+ watts continuous and 7,000+ watts surge capacity. A 7 kW generator like the Honda EU7000iS or Cummins Onan QG 5500 is the floor. A 10 kW unit like the Cummins Onan 10HDKCA gives margin and runs cooler at typical load.
Why pet groomers underspec more than food truck operators
Common first-time-operator mistake: assuming a 4 kW generator is enough because the dryer is “just” a hair dryer. The reality is high-velocity pet dryers are commercial-grade motors pulling 1,400 to 1,800 watts continuous, with surge to 2,800 watts at start. Add A/C running because customers expect it, water heater firing on a wash, and lights, and you are at 5,000+ watts with a single dryer and a single A/C running.
The 4 kW generator runs fine for the first dog. By dog three on a hot day, the A/C compressor cycles harder, you start the dryer mid-A/C cycle, and the breaker trips. You are now five minutes behind on every appointment for the rest of the day. Customers notice.
Sizing by operation type
Bath-only mobile (no scissor work, single dryer, light A/C use). 5 kW generator works. Honda EU5000iS, Champion 100485, similar. About $3,500-$5,500 installed.
Standard solo grooming (single tub, one dryer, dual A/C, full water heater). 7 kW. Cummins Onan QG 7000, Honda EU7000iS. About $5,500-$7,500 installed.
Premium / dual-tub grooming (two dryers, dual A/C, full kitchen). 10 kW. Cummins Onan QG 10000, Generac Mobile EZ Power. About $8,500-$11,500 installed.
Year-round mountain or hot-climate operating. Bump one tier up. The compressor cycle in 100F+ summers OR sub-zero winter heat-strip operation pulls more sustained current.
Honda vs Cummins Onan vs Generac
The three brands you should consider, with honest tradeoffs:
Honda EU series. Inverter generators, very quiet (60 dB at 23 ft for the EU7000iS), excellent for residential routes where neighbors notice. Slightly less robust under continuous duty than Cummins. Best for mobile grooming where customers are residential and noise matters. Honda EU7000iS retails $4,500-$5,500.
Cummins Onan QG series. Built for continuous commercial duty, mounted permanently in the truck, rated for thousands of run hours. Louder than Honda inverter (67 dB at 23 ft). Best for full-time use where reliability is paramount. QG 7000 retails $5,500-$7,000. QG 10000 retails $8,000-$10,500.
Generac Mobile. Mid-range pricing, decent reliability, parts availability is good across the U.S. Slightly heavier than Honda and Cummins. Best for budget-conscious operations. Comparable models run $4,000-$8,500.
Our default for full-time mobile grooming builds: Cummins Onan 7000 or 10000. Sized to your specific equipment list. Mounted in a sound-attenuated cabinet.
Diesel vs gas
About 90 percent of pet mobile generators are gas because the truck or chassis is gas. Same fuel system, simpler maintenance. Diesel generators are slightly more efficient (30 percent more BTU per gallon) and run longer between refuels, but they are louder at idle and more expensive up front. For 99 percent of pet mobile operators, gas is the right call.
Where the generator goes on the build
Three options:
- Under-bumper rear cabinet. Most common. Sound-attenuated steel cabinet between the rear axle and the bumper. Easy access for fuel and oil. Requires a tuned exhaust path exiting straight down or to the rear.
- Under-floor between axles. Lower CG, less obtrusive. Harder to service. Requires welded mounting frame.
- Roof-mounted. Rare on pet mobiles because of weight and noise above operator’s head. Sometimes used on RV-style conversions.
Whichever placement, NFPA 37 dictates clearance and venting requirements. We build to NFPA 37 by default.
Quiet matters more than you think
Noise compliance ordinances vary by city. Most residential zones cap at 60-65 dB at the property line. The Cummins Onan QG 7000 is rated 67 dB at 23 ft. The Honda EU7000iS is rated 60 dB. For especially noise-sensitive routes (gated communities, downtown apartment buildings, hospitals), we install a sound-attenuated enclosure that drops the rating another 5-7 dB.
Real-world: an operator in suburban Denver had to switch from a generic Chinese-import 8 kW open-frame to a Cummins Onan QG 7000 because three neighbors complained to the HOA. The Onan upgrade ran $4,500. Cheaper than the lawsuit threats.
Shore power inlet
Even with a generator, install a 50A shore power inlet. Many residential customers have RV outlets in their driveways. Operators who plug into shore power instead of running the generator save:
- $8-$15 in fuel per service day
- 30-60 minutes of generator runtime (extends service life)
- Noise complaints from neighbors
The shore inlet adds about $250-$400 to the build. Pays back within a few months.
How to size your own
Three steps:
- Add the running watts of every electric appliance that will ever run at the same time.
- Add the surge of the LARGEST single motor (compressor, dryer) on top of that continuous load.
- Round up to the next generator size. If your continuous is 5,200W and surge is 7,800W, the 5 kW unit is too small. Pick 7 kW.
If you tell us your equipment list, we will size the generator and quote it as part of the build. Get a free quote or call 719-722-2537.
Related: complete pet mobile business guide, cost breakdown, Zion Pet Mobiles overview.
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We design and build custom food trucks and trailers compliant with the regulations on this page. From a single phone call to keys-in-hand in 6 to 8 weeks for most builds.
Built in Woodland Park, Colorado. Delivered to operators in CO, AZ, NE, MT, and WY.