Adding Inverter

[Tal_IL]

I am thinking of adding a basic inverter to my class A rig. I just want to make a single outlet available in the kitchen. My layout will very easily allow me to connect a basic inverter to my house batteries.

I had an opportunity to pick up a 2000/4000 watt inverter, which would easily meet my needs. In reviewing the specs and installation instructions, I found the expected warning to only connect to 12V systems. But, I also found this: "use only 12 v batteries with this item". The installation instructions show diagrams for wiring both 2 battery and 3 battery banks using 12 v batteries in parallel only.

My 12V system is a pair of 6 volt batteries in series. Anyone know why an inverter can't be connected to a pair of 6 volt batteries in series?

[N7GLD]

One caution... I hard wired a surge protector last year. I added an inverter this year. The inverter has terminals for + an - and a ground post. I connected the ground to the chassis. The surge protector didn't like it when I turned the inverter on. Turns out that connecting bothe the - to the batteries and the ground to the chassis created a ground loop which caused the surge protector to do it's thing. I disconnected the chassis ground and it works fine.

[N7GLD]

One caution... I hard wired a surge protector last year. I added an inverter this year. The inverter has terminals for + an - and a ground post. I connected the ground to the chassis. The surge protector didn't like it when I turned the inverter on. Turns out that connecting bothe the - to the batteries and the ground to the chassis created a ground loop which caused the surge protector to do it's thing. I disconnected the chassis ground and it works fine.

[Canadian_Rainbi]

Tal/IL wrote:
I recently read an article about cooking on the go, using a crock pot via an inverter. The gist of it was when traveling to a destination where you will arrive late, you put dinner in the crock pot, set the crock pot in the sink to secure it and it cooks on the road so you have a hot dinner ready when you arrive. Seems like a good plan.

The crock pot would draw 850 - 1,000 watts, but I like to have excess capacity. And I'll be able to locate the inverter close to the battery bay.

We have 484 AH of battery, a Xantrex Prosine 2.0 inverter connected with less than three feet of 4/0 (0000) cable. Our inverter will draw the batteries down to less than 12 Volts when run for more than a minute. Short fat battery cables are critical.

We have also used a crock pot as you plan but it is a small one and draws less current. Note that a 1000 Watt load will draw over 80 amps at 12.0 volts and a 850 Watt load will draw about 70 amps. Note also that vehicle alternators are not designed to provide high current for sustained periods.

We now have a trimetric with shunt that shows the true battery output or input current. We haven't used the crock pot since but we do run the fridge on electric which draws about 40 amps from the battery. With the engine running and the sun shining (we also have 420 Watts of solar panels) there is a net gain of a few amps to the battery when the fridge element is drawing power.

I think you plan may be doable but keep an eye on battery voltage.

[MrWizard]

The warning means 12v systems, and should use better language
Your two 6s are one 12v

Treat it that way..neg on one battery, positive on the other battery
Opposite ends of opposing batteries,
Just connect at the same posts as your main battery cables

[Tal_IL]

I'm thinking "extra capacity" in terms of inverter capability. I only expect to use it when traveling and my assumption is the alternator would keep the batteries from being depleted.

[2oldman]

Tal/IL wrote:
The crock pot would draw 850 - 1,000 watts, but I like to have excess capacity. And I'll be able to locate the inverter close to the battery bay.

You don't have much excess capacity with just two batteries.

[Tal_IL]

I recently read an article about cooking on the go, using a crock pot via an inverter. The gist of it was when traveling to a destination where you will arrive late, you put dinner in the crock pot, set the crock pot in the sink to secure it and it cooks on the road so you have a hot dinner ready when you arrive. Seems like a good plan.

The crock pot would draw 850 - 1,000 watts, but I like to have excess capacity. And I'll be able to locate the inverter close to the battery bay.

[BFL13]

If the big wattage inverter is at a low price or even free, grab it. The number of batteries and how fat the wiring and fuse size has to be depends on what you are actually running with the inverter; not on what the inverter "could do."

Also, I find with my 3000w MSW inverter that it has no more additional draw on the batts running low watt appliances than a lower watt inverter does. There isn't much if anything to be saved there by getting a smaller inverter to run smaller things.

AFAIK from much time on this forum, the high stand-by draws of high wattage inverters are actually being quoted for inverter/chargers, with their huge batch of electronics to run their remotes and a zillion settable features. You see 2.3 amps or whatever. My 3000w inverter has a no -load standby amps draw of 0.5 amps.

It also has a remote on/off switch, that I use so when I am not inverting anything, I turn it off. Why leave it in standby? (Watch the TV set though. If you invert to run your laptop, the TV will be on in standby eating extra amps. Unplug the TV.

In actual use, the 3000w inverter draws fewer DC amps to run a CFL reading lamp than a 150w inverter does. Turns out that is because the 150w inverter is plugged into the Winegard 12v socket with long thin wires to the batteries, while the 3000w inverter is close to the batteries on fat wires.

In other words, "It depends!"

[pianotuna]

Hi,

Use #12 wire (or #10) from the inverter to the outlet you wish to install. Look for a 20 amp outlet at Home Depot.

[2oldman]

2000/4000 means running and surge.

[Sam_Spade]

Tal/IL wrote:

I had an opportunity to pick up a 2000/4000 watt inverter, which would easily meet my needs.

It probably would FAR exceed your needs and might not be a good idea.

The entire capacity of a 15 amp 110 V circuit is only about 1700 watts.
The bigger the inverter, the higher the operating losses are too.
If you ever got near 2000 watts, it would pull about 166 amps from the batteries and needs a VERY heavy gauge wire to support that. And would make your batteries low in short order.

What does 2000/4000 mean ?
What do you want to be able to run from this outlet ??

[2oldman]

No problem. It's still 12v - but those instructions are confusing for sure.

[Mandalay_Parr]

You are good to go. Mine are wired up he same way.