Inverter wire size?

50 amp fuse close to the battery or power source. I agree with #8 unless the distance is long go #6 wire.

Thanks for all the info. Pretty lame on electrical here. Inverter primarily for TV. What would be recommended fuse size?

Don't forget to fuse this new wire. I'd be tempted to direct connect to the battery bank, as the "house" wire is not rated for more than 30 amps.

There may be "inrush" current that may burn out a fuse--unless it is a slow blow. DAMHIK

I'd plan on 40 amps, so #8 is the right decision.

Learning what larry said is a good idea when doing any electrical work.

I=P/V

I=AMPS
p=POWER (OR WATTS)
V=VOLTS

I=425/12=35.4 AMPS

10G wire is rated 30amps.

I would go with #8

A friend gave me the inverter and didn't have the manual but your info helps. Thanks.

Not to be smart, but, what does you inverter manual recommend?

Most inverter manuals will give you a chart with distance and wire size recommendations. Choose the recommended wire size for the distance and include a fuse near the battery sized to that wire size (fuse protects you from having your rig burn down to the ground if the wire or inverter shorts out)..

Small inverters like yours often come with short length of 10ga wire, 425W would be about 30A at 12V so 10 ga would be absolute minimum for short distance (less than 5ft), 8Ga might be better choice if distance to battery is longer..

What’s the distance?

WindyNation’s wire charts will help you… https://www.windynation.com/jzv/inf/choosing-right-wire-size