What size of fuse to use for your inverter and battery bank?

This guide lists the common inverter fuse sizes (ratings) and DC battery bank commonly used in 12V power inverters to protect against:

  • Short-circuits at the battery bank that can result in the battery explosion
  • Short-circuits at the inverter power output
  • Inverter damage when the polarity of battery cables at the inverter is accidentally reversed

Depending on the inverter manufacturer, the fuses may be built in within the inverter and require a qualified service personnel to replace them or external replaceable ones that can easily be replaced by the user.

Note: You should always refer to the inverter manufacturer model for the fuse specifications – this is only a guide.

inverter fuse examples
Inverter fuse type examples

Indicative Inverter fuse sizes used in 12V inverters

The table below shows indicative fuse sizes for selected 12V inverters.

Note: The number and actual fuse sizes used may vary depending on the inverter manufacturer and model.

NoInverter size (watts)Fuse rating (A)
150030-40
275040
31,10040
41,50040
52,00040

Indicative Battery bank fuse sizes used in 12V inverters

These fuses protect the battery from danger such as explosions that may result from accidental short-circuits. They should be installed in battery cables as close to the battery terminal as possible.

The table below shows indicative indicative battery bank fuse sizes for selected inverter sizes.

Note: The actual fuse ratings used may vary depending on the inverter manufacturer and model

NoInverter size (watts)Battery bank fuse rating (A)
11,100110
21,500150
32,000200
43,000300
54,000400

Related questions about inverter fuses

# 1. Do I need a fuse between battery and inverter?

Yes, you need one – the battery bank fuse. It is usually inline and connected in the inverter wire that connects to the positive battery terminal.

# 2. What are the signs that an inverter has blown a fuse?

An inverter with a blown fuse may show any of the signs below:

  • Inverter does not power up or a continuous alarm sounds
  • No LEDS lighting up at all or for some inverters, a Red LED indicating a fault lights up

To fix a blown inverter fuse

# 1. First investigate what may have caused the fuse to blow. Sometimes it is easy to identify and correct, like a faulty appliance plugged into the inverter, faulty wiring or short-circuit across the inverter output terminals.

In some cases for example an internal inverter fault , you may need the services of a qualified technician.

# 2. Once the fault has been corrected, replace the blown fuse with one of the same type and rating.

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