Cable Size for a 2000W Inverter: Getting 1/0–2/0 AWG Right at 12V
What cable size for a 2000W inverter? At 12V the real draw is ~180–200A — we show why 1/0 AWG is the bare minimum (2/0 AWG is safer), how to size the fuse and voltage drop, and how to avoid cable fires.
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Last updated: May 2026 · Part of our 2000W DIY solar setup.
The most common — and most dangerous — way to save money on a DIY solar build is undersizing the cable between battery and inverter. This run carries the highest current in the whole system, and it’s exactly where people cut corners.
Short answer
For a 2000W inverter at 12V, plan on 1/0–2/0 AWG copper: 1/0 AWG only for very short runs, and 2/0 AWG as the safe choice for the real ~180–200A (4/0 AWG for runs up to ~10 ft). At 24V you can drop to about 4–2 AWG (2 AWG for the real ~90–100A). Add a fuse right at the battery positive (200–300A) — for a LiFePO4 battery a Class-T fuse is the safer pick because it interrupts the very high short-circuit current that ANL/MEGA fuses may not. Mount it as close as practicable and keep the run short.
Where the high current comes from
A 2000W inverter pulls ~167A at 12V on paper — and with efficiency and voltage sag under load, 180–200A in the real world. Your cable has to carry that continuously without meaningful heating.
| Load (12V) | Real current | Gauge (short runs) |
|---|---|---|
| 1000W | ~90A | 4 AWG |
| 2000W | ~180–200A | 1/0–2/0 AWG (2/0 safe) |
| 3000W | ~270A | 4/0 AWG |
At 24V the current halves, so the gauge does too (~4–2 AWG for 2000W). The figures assume short runs and a low voltage-drop target (~3%); for longer runs, go up a size — use a calculator for your exact length. Why 24V often pays off above 2000W is in our 12V or 24V guide.
Voltage drop & short runs
The thinner the cable and the longer the run, the bigger the voltage drop — aim to keep it small (well under ~3%). In practice: mount the inverter right next to the battery and keep the run short. Use an online calculator for your exact length, because gauge depends heavily on distance.
Don’t skip the fuse
A high-current fuse belongs right at the battery positive. It protects the cable in a short circuit — not the inverter. For a LiFePO4 battery, a Class-T fuse is the safer pick: it interrupts the very high fault current a lithium battery can deliver, where ANL/MEGA fuses may fall short. Size it to your cable’s ampacity and continuous load; 200–300A is typical for a 1/0–2/0 AWG 12V/2000W build. Mount it as close to the post as practicable, or the stretch before it is unprotected.
Copper, not CCA
Use pure copper (OFC). Cheap “CCA” cable (copper-clad aluminum) carries noticeably less current per gauge — the inverter run is the wrong place to save. If you do use CCA, go up at least one gauge.
The full build — battery, inverter, MPPT and wiring in the right order — is in our 2000W DIY solar setup. See also: 12V or 24V? and MPPT vs. PWM.
FAQ
What gauge wire for a 2000W inverter at 12V? +
Plan on 1/0 AWG for very short runs and 2/0 AWG as the safe choice for the real ~180–200A; for runs up to ~10 ft step up to 4/0 AWG. Size it for your exact length with a calculator.
Is 4 AWG enough for a 2000W inverter? +
No. 4 AWG is far too small for the ~170–200A a 12V/2000W inverter pulls. It overheats, voltage drop spikes and the inverter shuts down on low voltage. Use 1/0–2/0 AWG, or move to 24V.
What fuse goes on the battery cable? +
A fuse right at the battery's positive terminal — commonly 200–300A for a 12V/2000W setup. For a LiFePO4 battery a Class-T fuse is the safer choice (high interrupting capacity); ANL/MEGA may not safely break the very high short-circuit current. The fuse protects the cable, so match it to the cable's ampacity.
How close to the battery does the fuse need to be? +
As close as practicable — commonly within ~7 inches per ABYC, and within ~18 inches under typical NEC practice. The shorter the unprotected stretch, the lower the short-circuit risk.
Copper or copper-clad aluminum (CCA)? +
Use pure copper (OFC) for the battery-to-inverter run. CCA carries far less current per gauge; if you do use it, size up at least one gauge.