1988 Bronco 2, Installing a Power Inverter

[wildbill23c]

What's the recommended way to install a power inverter? I was thinking using a circuit breaker rather than a fuse, but what size should the circuit breaker be? I have access to a 5,000 watt inverter so that will be what gets installed.

I was also thinking of hooking the inverter up to a 2nd battery then using a battery isolator so I can charge both batteries but running the inverter will not drain the cranking battery.

 

[JerryC]

I'm not an engineer, this is just my way...
The circuit breaker will be used to protect the wire, so you size it according the amp load the wire can handle. The breaker must trip at less amps than the wire fails at.
You size the wire based off the max amp load of the inverter plus some extra for things like length and connectors and surge draw.
As rough examples, inverter fuse is a 50a, you size wire for 60a+ and the breaker for 55a. This way the breaker trips before the wire cooks and sets your truck on fire.

 

[wildbill23c]

The stuff I kept finding online keeps mentioning 400+ amp fuses or circuit breakers, but that doesn't sound right, or maybe it is. Since its going to be planned for a 3,000 to 5,000 watt continuous inverter, does a 400amp or higher fuse or circuit breaker sound right? The other issue is getting the proper wiring. Maybe this is a job for an electronics shop to do, they probably would know exactly what needs done. I'll try and see what I can find for information I guess.

Yes, I'd rather have it done right than destroy the vehicle.

 

[JerryC]

Take your watts and divide by battery voltage. Ex: 5000/12.7= 393.7 amps. That is assuming 5000w is the draw, not output. If that is the output then you need to factor in loss for the conversion from DC to AC. Imho, look up the max amp draw of the inverter and size by that.

 

[wildbill23c]

Take your watts and divide by battery voltage. Ex: 5000/12.7= 393.7 amps. That is assuming 5000w is the draw, not output. If that is the output then you need to factor in loss for the conversion from DC to AC. Imho, look up the max amp draw of the inverter and size by that.

Thanks for your help. I'll do some math...no not that new math where they add letters and there's no answer LOL.

Probably won't be doing the install until next spring when I get a chance to go get the inverter but I'd like to be prepared and know what I need to pickup.

 

[JerryC]

I guess I should have asked you why you need a 5000 watt inverter? I don't see how a single battery provides that much power for very long.

The factory alternator only puts out about 55-75 amps or about 750-1000 watts so your in a huge deficit when the inverter is running.

 

[wildbill23c]

I guess I should have asked you why you need a 5000 watt inverter? I don't see how a single battery provides that much power for very long.

The factory alternator only puts out about 55-75 amps or about 750-1000 watts so your in a huge deficit when the inverter is running.

The 5,000 watt inverter is free to me and its a pure sine wave, just have to go get it but its a 2 hour drive 1 way so I won't be going that direction for a while LOL.

I also plan on having a 2nd battery but I understand the inverter pulling max wattage won't work so well. Not even sure right now if the 5,000 watt inverter is even going to get mounted in the bronco 2, I think a 2,000 watt inverter to run smaller power tools if needed would be sufficient. Might not even proceed with my idea at all but all information given is always a help if I decide to do something in the future.

 

[JerryC]

Some random thoughts for you.
A small generator instead of an inverter. pro: useful away from the BII. con: have to carry it and the fuel to power it, needs storage space, cost.

Build a portable frame/box to house your second battery and the inverter, jumper cables to attach the BII to get current from the BII alternator/battery. Same pro as above. con: similar to above but no gas can to store.

Use battery powered tools. Pros: More cool tools! cons: cost, extra batteries and/or a way to recharge them in the field.

Back to the breaker, it's there to protect in the event the wire shorts to ground. The inverter should have its own overload/short protection. If the wire is run properly you wont have a need for a breaker. The battery cable doesn't have a breaker for example.

 

[wildbill23c]

Great thoughts, still wouldn't mind the inverter, possibly a much smaller one though.

A portable generator isn't exactly portable when you gotta lug that thing around, even on wheels it doesn't help when you gotta pick it up and load or unload it yourself LOL. Maybe some sort of rack, or a small trailer for it would make more sense then only have to hook up a trailer rather than move a 200+lb generator myself LOL.

Tons of ideas and thoughts, hopefully in this next year I'll get things all sorted out.

 

[JerryC]

I've seen youtube videos of the little 2000w inverter generators running saws. They aren't what I would call light but some people can carry them with one hand. The big advantage for the generator is that you could use it for other things, house backup power, camping, tailgating, etc...

This has been an interesting mental exercise

 

[wildbill23c]

Definitely mental exercise alright LOL. Been really thinking I need to get another generator anyhow, I sold my 3500 watt several years ago, but it wasn't 220V capable. I'd like to get one that has the 220V plug on it as the house would be easy to wire to run on a generator in a long term power outage situation if I had a 220V plug on the generator. Sure it won't run the whole house but the essentials it would do just fine with.

So I'm kind of thinking of just nixing the whole inverter idea, just buying 1 generator, a small trailer to make it easily mobile, even a wheel kit on a generator doesn't do so well in snow and gravel LOL. If I'm going to buy a generator I want one large enough to handle the house so I may just go that route here as soon as I can.

Thanks for your thoughts and ideas Jerry very much appreciated.

 

[JerryC]

I like that idea.

I've got a HF 3200/4000 generator I bought for an emergency backup. I've tested it running both my furnaces (4 ton and 2 ton) and fridge and there is still plenty left over for lights and TV's. This is all through 110v extension cords.

I have not run it for long periods as in the 2.5 years I have had we have not had an outage long enough to use it. But I do run it every couple of weeks to keep it ready. It starts every time on the first pull with one exception when it was 20 degrees outside it took four pulls.

 

[wildbill23c]

Thanks for your input Jerry. I think I may just go the generator route. Possibly a small power inverter enough to at least run a battery charger when a generator would be overkill LOL.

 

[wildbill23c]

Revisiting the power inverter option, realizing a 5k inverter isn't going to really fit where I wanted to put an inverter. My Bronco 2 has the side storage boxes in the back cargo area, so I think I want to get an inverter that will fit in one of those spaces so its installed out of the way. I think a 2k or 3k inverter would be plenty of power for anything I'd need for on the road. Anything more than that I would certainly want a generator anyhow, and HF does have a 11,000 watt continuous generator with 220V capability which would easily run many circuits in the house if needed. I'd be mounting on a small trailer though.

I ordered a cable kit for that 5k inverter which required a 500amp fuse, however with the smaller inverter it will only require a 250-300amp fuse so I'll just swap fuses out and should be good to go on that. Hopefully I can get this all sorted out in the next month or so and a few pictures posted of how the inverter install goes.

Eventually I think I'd like to add a 2nd battery with an isolator and power my radios and the inverter off the 2nd battery leaving the stock battery as the cranking battery only...and the 2nd battery as a backup cranking battery if needed.