Pick between the Grid Doctor 3300 and 300 by your loads, not by price. The 300 (300W, 320Wh) covers small electronics and a CPAP overnight. The 3300 (3,300W, 2,048Wh) adds a refrigerator and power tools. Neither is a full-home system. Prices and specs below come from My Patriot Supply, read 2026-11-04.
Disclosure: If you order through a My Patriot Supply link on this page, this site earns a commission. Your price stays the same. How we are paid.
Side by side
Everything in the "seller" column is My Patriot Supply's own listing, read 2026-11-04. Price per Wh is our arithmetic, with one panel included in each price.
| Grid Doctor 3300 | Grid Doctor 300 | |
|---|---|---|
| Price | $2,997 with one 200W panel | $497 with one 100W panel |
| Continuous / surge output | 3,300W / 6,600W | 300W / 600W |
| Stored energy | 2,048Wh LiFePO4 | 320Wh LiFePO4 |
| Weight | 57.2 lb | 8.625 lb |
| Ports | 15, including four 120V/20A and one 120V/30A | 9, including two AC |
| Solar input, per seller | Up to 5 panels of 200W (1,000W) | Up to 2 panels of 100W (200W) |
| Extra panel | $447 for a 200W panel | $247 for a 100W panel |
| Expansion | 2,048Wh batteries; see the conflict below | Units can be stacked, each independent |
| Cycle figure on the page | 3,500 | 2,000+ (800 to 80%) in specs; 3,500 in a blurb |
| UPS switchover | Seller says 15 ms | No UPS claim |
| EMP wording | Seller markets built-in intercept technology | None |
| Price per Wh (ours) | $1.46 | $1.55 |
| Own stated limit | Not ideal where you need 240V for large HVAC or full-home load panels | Not designed for full-size fridges, microwaves, sump pumps, space heaters or HVAC |
Two seller conflicts show up in this table. The 3300 page says up to 7 expansion batteries (16,384Wh) in its specifications and up to four in its FAQ, and we print both without picking. The 300 page gives its cycle life as 2,000+ in one place and 3,500 in another.
The math: 6.4 times the capacity for 6.0 times the price
The 3300 stores 2,048Wh against 320Wh, which is 6.4 times as much. Its price is $2,997 against $497, which is 6.0 times as much, a gap of $2,500. That is why its cost per watt-hour comes out lower, $1.46 against $1.55. Price per Wh is only one criterion: the 3300 weighs 57.2 lb, and the 300 can sit in a bag.
What each can carry
Hours below use hours = Wh x 0.85 / watts, where 0.85 is our labelled planning assumption. The watts are illustrative assumptions, not sourced figures: read your own labels.
| Load (assumed watts) | 3300 planning hours | 300 planning hours |
|---|---|---|
| Wi-Fi router (10W) | 174.1 | 27.2 |
| Four LED bulbs (40W) | 43.5 | 6.8 |
| CPAP, no humidifier (40W) | 43.5 | 6.8 |
| 42-inch LED TV (80W) | 21.8 | 3.4 |
| Mini refrigerator (80W) | 21.8 | 3.4 |
| Full-size refrigerator, average draw (150W) | 11.6 | 1.8 |
| Gas furnace blower (400W) | 4.4 | Not possible, above 300W |
| Sump pump, running (800W) | 2.2 | Not possible, above 300W |
Motors need a surge check as well as a running-watts check. A refrigerator compressor starts above its running watts, which is comfortable against 6,600W and a closer call against 600W. Our refrigerator runtime guide goes through it, and the watts guide shows how to total a list of loads.
Pick the 300 if
- You rent, travel or live in a small place and the list is phones, a router, lamps and a CPAP.
- You want something you can lift with one hand.
- A short outage is the case you are planning for.
Pick the 3300 if
- A refrigerator, a chest freezer or a sump pump is on your must-run list.
- You want to power corded tools or several devices at once.
- You want room to add panels and, per the seller, expansion batteries.
Our own sizing is cautious. Ready.gov and food-safety guidance say a closed refrigerator keeps food cold about 4 hours and a full freezer about 48. Beyond that, a battery matters. The 300 gets a full-size fridge through under two hours on paper; the 3300 gets it through about eleven.
Pick neither if
You need 240V, a hardwired well pump, central air conditioning or a full-home panel. The seller says the 3300 is not ideal for those, and the 300 is much further from them. Do not plug a power station into a wall outlet to power the house. For a gas option, read power station vs generator.
Using both
A layered plan is common: the 3300 for the kitchen and the sump pump, the 300 for the bedroom and the router. Our reasoning is simple: two devices means two single points of failure instead of one, and a small unit can keep a phone and a CPAP going while the large one is busy with the fridge.
Read each model on its own page: the Grid Doctor 3300 review and the Grid Doctor 300 review. For the wider choice, see the guide to the best portable power station for home backup and the best solar generator for home backup.
Charging compared
Both units refill from a wall outlet, from solar and from a vehicle port, per the seller. The seller lists the 3300's wall charging at 1,800W quick or 600W slow, and the 300's adapter at 80W. Our arithmetic, with no losses counted, gives roughly 1.1 hours for the 3300 at the quick rate and about 3.4 hours at the slow rate, and about 4 hours for the 300 at 80W. Real times run longer. The point is proportion: the large unit refills quickly relative to its size, while the small one is slow relative to its own. If you expect repeated outages with sun available, the extra panels matter more than the headline watts.
What neither unit changes
Whichever you pick, the sensible habits are the same: charge it before storm season, keep it ventilated while it charges, read the manual's storage notes (the seller advises 60% or more charge and a top-up every three months) and keep an eye on the temperature range, 14 to 104 F in use according to the seller.
FAQ
Is the Grid Doctor 3300 worth six times the price of the 300?
It stores 6.4 times the energy and outputs 11 times the watts. If your loads fit within 300W and a few hours, the 300 is the lighter, cheaper fit. If a refrigerator or pump is on the list, the 300 cannot carry it.
Can the 300 power what the 3300 can?
Not above 300W. A furnace blower or sump pump at our assumed watts exceeds it, and the seller says it is not designed for full-size fridges.
Which one has more solar input?
By the seller's listing, the 3300 accepts up to 1,000W (five 200W panels) and the 300 up to 200W (two 100W panels). Recharge time depends on sun, not only panel watts.
Do either of them work as a full-home backup?
No. Both are plug-in units for cords, and the seller says the 3300 is not ideal for 240V or full-home panels.
Sources
- My Patriot Supply, Grid Doctor 3300 product page, read 2026-11-04: https://www.mypatriotsupply.com/products/grid-doctor-3300-emp-solar-generator
- My Patriot Supply, Grid Doctor 300 product page, read 2026-11-04: https://www.mypatriotsupply.com/products/solar-generator-300w-by-grid-doctor
- Ready.gov, Power Outages, read 2026-11-04: https://www.ready.gov/power-outages
Update history
| Date | Change |
|---|---|
| 2026-11-04 | First published |