1000 Watt Inverters Compared: What They Run, Amp Draw and Pure Sine
A 1,000-watt inverter runs laptops, TVs, chargers, many power tools and smaller kitchen appliances from a 12-volt battery — but not most microwaves, hair dryers or space heaters. At full load it draws over 90 amps, so it has to be wired to the battery. Here is how the 1,000-watt inverters we carry compare.
- 1,000 watts divided by 12 volts is about 83 amps; with inverter losses, plan on about 93 amps at full load
- Too much for a lighter socket: wire it to the battery with a fuse
- Check the continuous rating: the Xantrex PROwatt SW 1000 is rated 900 watts continuous and 1,000 watts maximum
- Most microwaves draw 1,200 watts or more from the inverter; for one, look at 1,500 or 2,000 watts
Pick by what you are running
| Continuous power | Surge | Waveform | Full-load battery draw | Outlets and extras | ||
|---|---|---|---|---|---|---|
|
Samlex PST‑1000‑12
Best 1,000 W pure sine
|
1,000 W | Not listed | Pure sine | ~93 A at 12 V | 2 GFCI | BUY NOW |
|
Samlex NTX‑1000‑12
Current Samlex mid-range
|
1,000 W | Not listed | Pure sine | ~93 A at 12 V | Remote option | BUY NOW |
|
Xantrex PROwatt SW 1000
Truck and RV installs
|
900 W | 1,200 W | Pure sine | ~83 A at 12 V | 2 GFCI + USB, display | BUY NOW |
|
Samlex SAM‑1000‑12
Budget pick
|
1,000 W | Not listed | Modified sine | ~93 A at 12 V | Power-save mode | BUY NOW |
|
Samlex PST‑1000‑24
For 24 V
|
1,000 W | Not listed | Pure sine | ~46 A at 24 V | 2 GFCI | BUY NOW |
How many amps does a 1,000-watt inverter draw?
1,000 watts divided by 12 volts is about 83 amps, but no inverter is 100% efficient, so plan on about 93 amps from a 12-volt battery at full load — more as the battery voltage sags. At 24 volts it is about 46 amps. Our inverter calculator works it out for your loads and gives the cable size.
What will a 1,000-watt inverter run?
Laptops, TVs, game consoles, battery and tool chargers, fans, lights, a blender, a small coffee maker and many power tools such as drills and jigsaws. It will not run a hair dryer or space heater, and most microwaves draw 1,200 watts or more from the inverter — see our 12 volt microwave guide. Add up what runs at the same time, and allow for the startup surge of anything with a motor.
Can I plug a 1,000-watt inverter into a cigarette lighter socket?
No. A vehicle power socket is fused at 15 to 20 amps, about 150 to 200 watts. A 1,000-watt inverter draws over 90 amps at full load, so it must be wired to the battery with properly sized cable and a fuse close to the battery.
What cable and fuse does a 1,000-watt inverter need?
The gauge depends on the length of the run — the inverter calculator gives it — and the inverter manual gives the fuse rating; our Class T fuse guide covers the fuse types. Samlex sells a matching DC-1000-KIT with a pair of heavy-duty cables and a fuse assembly, and Go Power’s GP-DC-KIT2 is rated for 600 to 1,000-watt inverters.
Is the Xantrex PROwatt SW 1000 really a 1,000-watt inverter?
It is rated 900 watts continuous and 1,000 watts maximum, with a 1,200-watt surge. For loads up to about 900 watts it is a good fit, and its display, USB port and ignition lockout suit truck and RV installs. For loads that run near 1,000 watts for long periods, choose a model rated 1,000 watts continuous.
Bottom line
Check what you will run first: a 1,000-watt inverter covers electronics, chargers, tools and small appliances, but not most microwaves. For a heavy-duty 12-volt pure sine unit, the Samlex PST-1000-12 is the pick, and the NTX-1000-12 is Samlex’s current mid-range model. The Xantrex PROwatt SW 1000 suits truck and RV installs with loads up to 900 watts, the modified sine SAM-1000-12 saves money on simple loads, and the PST-1000-24 halves the current on a 24-volt bank. Wire it to the battery with cable and a fuse sized for about 93 amps.
