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.
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.
No | Inverter size (watts) | Fuse rating (A) |
1 | 500 | 30-40 |
2 | 750 | 40 |
3 | 1,100 | 40 |
4 | 1,500 | 40 |
5 | 2,000 | 40 |
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
No | Inverter size (watts) | Battery bank fuse rating (A) |
1 | 1,100 | 110 |
2 | 1,500 | 150 |
3 | 2,000 | 200 |
4 | 3,000 | 300 |
5 | 4,000 | 400 |
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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