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# How to wire up an inverter?

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Maybe someone here can help, I've had no luck asking around locally.

What I want to do is wire up an inverter in my van. I think the biggest load I ever would need is for the aircompressor (an average size, for maybe 10 minutes to fill the tank), or a small microwave.

So I guess I need to wire it directly to the battery, I'm interested in how to do this, what size fuse to use, what battery to use, what I need so I can isolate the second battery from the starting battery but still charge it when the van is running, and I'm curious if I will ruin my alternator by doing this. I'm assuming that the alternator would charge the lowest battery first if both are connected.

Any help in this area is great. I love equations on how long run time at loads are, and battery facts.

Thanks

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Maybe someone here can help, I've had no luck asking around locally.

What I want to do is wire up an inverter in my van. I think the biggest load I ever would need is for the aircompressor (an average size, for maybe 10 minutes to fill the tank), or a small microwave.

So I guess I need to wire it directly to the battery, I'm interested in how to do this, what size fuse to use, what battery to use, what I need so I can isolate the second battery from the starting battery but still charge it when the van is running, and I'm curious if I will ruin my alternator by doing this. I'm assuming that the alternator would charge the lowest battery first if both are connected.

Any help in this area is great. I love equations on how long run time at loads are, and battery facts.

Thanks

If you are going to run a compressor, it will need to be a big inverter. And amps will be critical in determining wire size. If you dont go big enough on wire size, tyhe inverter wont work. A 2000 watt inverter will require #6AWG wire, just to give you an idea. A 30 amp will require 10 AWG, larger if you go over 6 feet.

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I don't know if a 2000 watt inverter will start a normal compressor. You might be better off just getting a high volume 12 volt model. It will fill tires, but not air tools. A 2000 watt inverter should run a small lower wattage microwave. However, it will drain your battery in fast. It will also be hard on your battery. If you have the vehicle engine running, that alternator will supply a good part of the juice and not be as hard on the battery. 2000 watts means around 90 amps at 12 volts. That's a lot of current. It will drain the battery in just 15 or so minutes. Keep the leads from the battery to the inverter as short as possible. No more than a foot or two.

Smaller loads like a small TV or a few lights will last for a few hours.

As far as running multiple batteries, you need what is called a battery isolator. There are two kinds diode and relay. Get a relay type. The diode ones have some voltage drop and your batteries will never fully charge. They are usually available at motorhome dealers/shops. Camping World may be a good source.