What gauge cable do I need between a battery and a 2,000W inverter?

At 12V, a 2,000W inverter pulls about 196A continuous, which needs at least 2 AWG for a run up to about 3 ft one-way, 1 AWG up to about 5 ft, and 3/0 AWG by 10 ft one-way, based on the ABYC ampacity and 3 percent drop combination in the table above. At 24V the same inverter only pulls about 98A, which needs 6 AWG for the same short runs.

Why does inverter cable need to be so short?

Because the current is very high, often 100A to 300A for a mid-size to large inverter, and both voltage drop and cable cost scale with length at that current. Installers keep the inverter physically close to the battery bank specifically to keep this run short, since even a few extra feet can jump the required gauge up multiple sizes, as shown in the 1 ft versus 10 ft columns above.

What size fuse protects an inverter cable?

The fuse should be rated at or below the cable's ampacity, not sized to the load the inverter draws, since its job is protecting the conductor from a fault rather than limiting normal operating current. A 2 AWG cable at 210A ABYC ampacity pairs with a 200A class ANL or MEGA fuse, per the table above, which is the standard practice this page's fuse matching table follows.

Does 24V wiring really need thinner cable than 12V for the same inverter?

Yes, and the tables above show it directly. The same 2,000W inverter needs 3/0 AWG at 12V over a 10 ft one-way run but only 4 AWG at 24V over the identical run, because doubling system voltage halves the current for the same power, and both ampacity requirements and voltage drop scale with current.

Can I use ampacity alone to size a battery cable and skip the voltage drop check?

Not reliably. At the very short lengths common in battery cable runs, ampacity is often the binding constraint, but as the run gets even a few feet longer, voltage drop can become the tighter limit at these high currents, as shown by the 1 ft versus 10 ft columns in the tables above. Both checks have to pass, and the smaller resulting cable size, meaning the larger gauge number, is not automatically correct without checking both.

What is a busbar for, and do I need one?

A busbar is a single metal terminal block that lets multiple heavy cables connect at one point instead of stacking several ring terminals on a single battery post or lug, which is both a mechanical problem and a connection quality problem at high current. Most installs with more than a battery and an inverter, such as one that also adds a DC-DC charger or a solar charge controller output, benefit from a busbar rated for the combined current those connections carry.

Reference

Battery and Inverter Cable Size Chart by Current and Length

Researched from published standards and manufacturer specifications. Updated 2026-09-17.

Quick answer

A 2,000W inverter pulls close to 196A at 12V, and over a 1 ft one-way run that needs 2 AWG copper to stay within ABYC E-11's 3 percent critical drop limit, rated at 210A ampacity. The same load at 24V pulls about half that current, 98A, and needs only 6 AWG at the same 1 ft run. Battery-to-inverter cable is almost always short but very high current, which is why gauge and length both matter even over a few feet.

Battery and inverter cable is a special case of the general voltage drop and ampacity problem, distinguished mainly by how much current flows through a very short run. A 3,000W inverter can pull close to 300A from a 12V bank, current that would need a heavy conductor over any real distance but that a battery bay's actual few feet of cable can carry on a size that would otherwise look undersized. The tables below apply the exact same NEC Chapter 9, Table 8 resistance figures and ABYC E-11 ampacity table this site's wire gauge calculator uses, at the current levels three common inverter sizes actually draw.

Both the conductor's ampacity and its voltage drop have to pass at the same time, and the smaller of the two allowed lengths governs. At high current and very short length, ampacity is usually the binding constraint; as the run gets longer, voltage drop takes over even at these currents.

Minimum cable gauge for common inverter DC currents, 12V

DC amps assumes the 0.85 inverter efficiency convention at each inverter's full continuous rating. Cable gauge is the smallest conductor that clears both ABYC E-11 ampacity and the 3 percent critical voltage drop limit at that one-way length.

Minimum battery cable gauge by inverter size and one-way run length, 12V, ABYC E-11
Inverter (continuous)	DC amps at 12V	1 ft one-way	3 ft one-way	5 ft one-way	10 ft one-way
1,000W	98.0A	6 AWG (0.8% drop)	6 AWG (2.41% drop)	4 AWG (2.52% drop)	1 AWG (2.52% drop)
2,000W	196.1A	2 AWG (0.63% drop)	2 AWG (1.9% drop)	1 AWG (2.52% drop)	3/0 AWG (2.5% drop)
3,000W	294.1A	2/0 AWG (0.47% drop)	2/0 AWG (1.42% drop)	2/0 AWG (2.37% drop)	4/0 AWG (2.98% drop)

Published standard Source: ABYC E-11 105 C ampacity table and NEC Chapter 9, Table 8 resistance, at the ABYC E-11 3 percent critical circuit drop limit; DC amps uses the 0.85 inverter efficiency convention. Every result respects ABYC ampacity first, then the 3 percent drop limit, exactly as this site's wire gauge calculator computes it.

The same inverters at 24V

Halving the current at 24V lets a noticeably smaller conductor cover the same run. A 2,000W inverter that needs 3/0 AWG at 12V over 10 ft needs only 4 AWG at 24V over the same distance.

Minimum battery cable gauge by inverter size and one-way run length, 24V, ABYC E-11
Inverter (continuous)	DC amps at 24V	1 ft one-way	3 ft one-way	5 ft one-way	10 ft one-way
1,000W	49.0A	10 AWG (0.51% drop)	10 AWG (1.52% drop)	10 AWG (2.53% drop)	6 AWG (2% drop)
2,000W	98.0A	6 AWG (0.4% drop)	6 AWG (1.2% drop)	6 AWG (2% drop)	4 AWG (2.52% drop)
3,000W	147.1A	4 AWG (0.38% drop)	4 AWG (1.13% drop)	4 AWG (1.89% drop)	2 AWG (2.38% drop)

Published standard Source: Same ABYC E-11 ampacity table and NEC Chapter 9, Table 8 resistance as the 12V table above, computed at 24V.

Matching a standard fuse or breaker to each cable size

A fuse protecting a conductor should be rated at or below that conductor's ampacity, which is a different sizing rule than the 125 percent continuous load rule this site applies to circuit fuses elsewhere. This table picks the largest standard NEC 240.6(A) rating that does not exceed each conductor's ABYC ampacity.

Largest standard fuse or breaker at or below each conductor's ABYC ampacity
AWG	ABYC ampacity	Largest standard fuse at or below	Typical ANL/MEGA fuse class
6	120A	110A	100 to 110A
4	160A	150A	150A
2	210A	200A	200A
1	245A	225A	225A
1/0	285A	250A	250A
2/0	330A	300A	300A
3/0	385A	350A	350A
4/0	445A	400A	400A

Published standard Source: ABYC ampacity from the table above; standard fuse and breaker ratings from NEC 240.6(A). This protects the cable from overcurrent. It is a separate question from what breaker size a continuous load itself needs, covered on the fuse size calculator.

When the answer is a higher system voltage instead of heavier cable

Every row in the tables above holds current fixed by holding inverter wattage and system voltage fixed, but the 24V table shows what happens when the second variable moves. An owner planning a large inverter, 3,000W or beyond, on a battery bay that is not immediately next to the inverter often finds that a 24V or 48V house system keeps cable size and cost reasonable in a way a 12V system cannot without genuinely heavy copper. That decision reaches beyond the cable alone, since it touches the battery, the charge controller, and every other component's own voltage rating, which is the full tradeoff covered on the 12V versus 24V comparison rather than something to decide from cable size alone.

A fuse or breaker with an interrupt rating lower than the actual fault current a battery bank can deliver may not safely clear a short. Battery-to-inverter cable sits closest to the highest fault current in the whole system. Check the published interrupt rating on any fuse or breaker used at the battery against your bank's real fault current, not just its continuous amperage rating.

Cable, fuse and busbar hardware sized to this chart

Beginner Short 1,000W runs

TOPDC

TOPDC 4 AWG Battery Cable Pair, 18 in

$11.98

An 18 in pair in 4 AWG, sized for the shorter one-way lengths in the 1,000W inverter row below.

Best for: Short battery to busbar runs.

Check price on Amazon

Intermediate 200A fuse class

BOJACK

BOJACK 200A Inline ANL Fuse Holder with Fuse

$15.99

Matches the 2 AWG and 1 AWG rows in the fuse table below, with a lug range built for 4 AWG to 1/0 AWG cable.

Best for: Fusing an inverter feed at the battery.

Check price on Amazon

Expert Main disconnect

Blue Sea Systems

Blue Sea Systems m-Series On/Off Battery Switch

$27.05

A disconnect switch belongs in every one of these runs, sized to the same current the cable and fuse are rated for.

Best for: A main disconnect you trust.

Check price on Amazon

Frequently asked questions

What gauge cable do I need between a battery and a 2,000W inverter?: At 12V, a 2,000W inverter pulls about 196A continuous, which needs at least 2 AWG for a run up to about 3 ft one-way, 1 AWG up to about 5 ft, and 3/0 AWG by 10 ft one-way, based on the ABYC ampacity and 3 percent drop combination in the table above. At 24V the same inverter only pulls about 98A, which needs 6 AWG for the same short runs.
Why does inverter cable need to be so short?: Because the current is very high, often 100A to 300A for a mid-size to large inverter, and both voltage drop and cable cost scale with length at that current. Installers keep the inverter physically close to the battery bank specifically to keep this run short, since even a few extra feet can jump the required gauge up multiple sizes, as shown in the 1 ft versus 10 ft columns above.
What size fuse protects an inverter cable?: The fuse should be rated at or below the cable's ampacity, not sized to the load the inverter draws, since its job is protecting the conductor from a fault rather than limiting normal operating current. A 2 AWG cable at 210A ABYC ampacity pairs with a 200A class ANL or MEGA fuse, per the table above, which is the standard practice this page's fuse matching table follows.
Does 24V wiring really need thinner cable than 12V for the same inverter?: Yes, and the tables above show it directly. The same 2,000W inverter needs 3/0 AWG at 12V over a 10 ft one-way run but only 4 AWG at 24V over the identical run, because doubling system voltage halves the current for the same power, and both ampacity requirements and voltage drop scale with current.
Can I use ampacity alone to size a battery cable and skip the voltage drop check?: Not reliably. At the very short lengths common in battery cable runs, ampacity is often the binding constraint, but as the run gets even a few feet longer, voltage drop can become the tighter limit at these high currents, as shown by the 1 ft versus 10 ft columns in the tables above. Both checks have to pass, and the smaller resulting cable size, meaning the larger gauge number, is not automatically correct without checking both.
What is a busbar for, and do I need one?: A busbar is a single metal terminal block that lets multiple heavy cables connect at one point instead of stacking several ring terminals on a single battery post or lug, which is both a mechanical problem and a connection quality problem at high current. Most installs with more than a battery and an inverter, such as one that also adds a DC-DC charger or a solar charge controller output, benefit from a busbar rated for the combined current those connections carry.

Measure the actual run before buying cable. The difference between a 1 ft and a 10 ft one-way distance can move the required gauge up several sizes at inverter-level current, so confirm the real length in your battery bay against the tables above rather than assuming a common pre-made cable length will cover it.