Wiring inverter to charge controller/battery?

[sultan316]

Usually taking a DC meter will tell you the VOLTS at the end of the wire from the battery bank to the inverter..

Put leads on the ends of the wire where they hook onto the inverter itself..

http://www.amazon.com/Whistler-Pro-2.../dp/B003R7CAX8

that is my inverter. I can't really measure the wire. I can take it off the battery and put the leads on the clips, but that shouldn't give me anything since it's not connected to a power source

[epsgunner]

Your losing me here..

The battery wire that goes to the inverter..

The power is from the battery.. the idea is to measure the VOLTS as it goes into the inverter.. you don't need an inverter to measure the VOLTS..

Can you NOT get to the end of the wires near the inverter???

Here is a picture of my HOT wire that goes UP from the battery to the switch to where then inverter would be..



You need to measure the VOLTS at the TOP where it goes to the inverter.. inverter need not be attached at all.

Were trying to see if your having a WIRE voltage LOSS..

You need to use a DC VOLTAGE meter and test the voltage..

I am using 3/0 AWG wire... so my loss even at 42" of wire is VERY VERY LOW.

If you are unconfortable doing this ask an adult.. or certified & licensed electrician..

[epsgunner]

Disregard the last post.. that inverter has a hardwired lighter plug on it..

I can't help you on that issue..

[sultan316]

Well I was waiting for another response, but I guess nobody has anything. epsgunner, I am an adult ha, but you got what I was going to respond with the hardwired plug. I might consider opening up the inverter with the screws on the back. This thing will never finish apparently

If anybody has any other ideas or can help at all it would be greatly appreciated! Thanks again

[epsgunner]

Its so hard to tell on the internet the age of the people, so no offense.

We can't tell you to open things up and modify things and such..

Try looking with ggle on other sites that show pictures of installs..

You won't see a little inverter with a hardwire car cord.. or alligator clips..



Notice the 6 AWG wire from the controller to the battery bus bar with a 100 amp circuit breaker.. and the battery switch rated for upto 500 amps... and the 3/0 heavy wire for the inverter on the right. (I will be cutting that 42" wire to about 12" when I am ready to install..)

I've only got 870 watts of panels.. but that 60 amps going to the battery per hour and upto 250 amps being drawn from my 2000-3000 watt inverter has me wide awake to make sure I do it correctly..

[sultan316]

Its so hard to tell on the internet the age of the people, so no offense.

We can't tell you to open things up and modify things and such..

Try looking with ggle on other sites that show pictures of installs..

You won't see a little inverter with a hardwire car cord.. or alligator clips..



Notice the 6 AWG wire from the controller to the battery bus bar with a 100 amp circuit breaker.. and the battery switch rated for upto 500 amps... and the 3/0 heavy wire for the inverter on the right. (I will be cutting that 42" wire to about 12" when I am ready to install..)

I've only got 870 watts of panels.. but that 60 amps going to the battery per hour and upto 250 amps being drawn from my 2000-3000 watt inverter has me wide awake to make sure I do it correctly..

None taken! You're only trying to help. Yea honestly it seems like nobody else is just building a single panel for the hell of it. Most are actually getting systems as a whole, so they dont have to deal with a car plug inverter. I'll just see what I can do :/

[peterntu]

Inverter and charge controller

The inverter must be connected directly to the battery terminals. It will have to be able to draw high current from the battery. Typically the load terminals on a CC will deliver power to an optional non-battery load when there is more power available on the input terminals of the CC than is needed for battery charging. But to be sure, you have to depend on the bad manual of the CC.

An inverter will often blink its fault light when first connected to the battery. And it may make what some would consider a loud humming (120 Hz) when delivering power to a load. But the fault light should not come on again under load, unless the inverter is defective, the battery or wiring are inadequate for the load power, or the load is greater than the inverter was designed for.
A clicking buzz, with the fault light coming on or flickering is bad.

The battery is described as a 35AH AGM (absorbed glass mat) unit, which should be able to provide 10 amps or more for a short term with low resistance. That would give you enough for about 80 watts out of the inverter. What are you using as your test load?
If the battery indication (three LEDs on the CC) means what you suspect, the battery is nowhere near fully charged in the picture and should not be loaded down until you have charged it fully.

If you are adventurous, connect the inverter to your car battery to test it.

"The inverter must be connected directly to the battery terminals..."

Question 1:

Missing somthing, shutdown time. If inverter is wired to battery and not through charge controller. How do you control the "sundown shutdown after five (5) hours", the load settings on the charge controller?

Question 2:

After wiring my 1000 watt inverter to 30 AMP charge controller load port, load shorted and I waited for two days and will not come back up. What else can I do to recover my load from charge controller?

[Mike90250]

The LOAD terminals on a charge controller, are ONLY for a small load, not an inverter. The manual usually tells you this.

I doubt it will "recover", the solid state switch internal to the controller is fried.

You can use the controller load terminal to control a proper sized relay, to control your large load.

[thastinger]

ok but how do I measure the voltage at the input of the inverter? Isn't the input of the inverter at the battery terminals? If so, that typically fluctuates between 11-14V like I said before.

Yeah, it is the same electrical point so the reading will be the same regardless of where you take it in the line...I assume you have the inverter leads hooked directly to the battery leads anyways. I think what you need to figure out is the amps your inverter draws from the battery for a given load, then look up some wiring specs to see how many amps your battery to inverter wire can supply.

[Sunking]

Yeah, it is the same electrical point so the reading will be the same regardless of where you take it in the line...I assume you have the inverter leads hooked directly to the battery leads anyways. I think what you need to figure out is the amps your inverter draws from the battery for a given load, then look up some wiring specs to see how many amps your battery to inverter wire can supply.

Incorrect answer and will lead to false conclusions. When an inverter is under load, the voltage at the input of the inverter WILL BE LOWER than what is at the battery terminals every time. If it exceeds 2% then the cables are too small for the distance and current.

[thastinger]

Incorrect answer and will lead to false conclusions. When an inverter is under load, the voltage at the input of the inverter WILL BE LOWER than what is at the battery terminals every time. If it exceeds 2% then the cables are too small for the distance and current.

I don't know what you were in the Navy but I suppose BE&E wasn't part of your training pipeline....it is the same piece of wire, explain to me how you can electrically get one voltage reading 2 feet from the other...would the center be a good average voltage? lol

[inetdog]

I don't know what you were in the Navy but I suppose BE&E wasn't part of your training pipeline....it is the same piece of wire, explain to me how you can electrically get one volatge reading 2 feet from the other...would the center be a good average voltage? lol

I doubt that Dereck will take the time to reply politely to this, so here I go:

Everything except a superconductor will have resistance. We are just used to treating copper wire as it it had none. But I think you will agree that if I keep making that copper wire smaller and smaller and keep running the same current through it, it will start to heat up. That heat is the result of the resistance in the wire and the numeric value of the power in watts that is heating the wire is the current running through it times the voltage drop from one end to the other.

If there is no current flowing, there will be no voltage drop. We can all agree on that, I think. But if an inverter is drawing 70 amps at 12 volts, I hope you can see that the voltage from one end of the wire to the other will be measurable, even if not so high as to cause problems.

In our normal household wiring, the current is low and the voltage is high so that a 1 or 2 volt drop along the wire is not noticeable. But a 1 or 2 volt drop out of 12 volts is very large.

Another area where this is easier to see in practice is with low voltage landscape lighting. You are using typically 14 gauge wire or larger, but have to worry about the voltage drop in tens of feet of cable supplying multiple lights.

I don't know what you were in the Navy but I suppose BE&E wasn't part of your training pipeline

Sorry, could not resist that one. With apologies in advance: "Did you get your electrical training in the Marines?"

[Sunking]

I don't know what you were in the Navy but I suppose BE&E wasn't part of your training pipeline....it is the same piece of wire, explain to me how you can electrically get one volatge reading 2 feet from the other...would the center be a good average voltage? lol

Joke is on you partner. They did not teach you anything about Ohm's law and voltage drop on wiring in the Navy or you passed out during the lecture. Anyone in this biz knows low voltage inverters knows voltage drop on wiring is an issue and not the same point electrically. The wires are resistors.

Again if anyone who wants to know if there is more than a 2% voltage drop between your battery and inverter input at full loads, your wire is too small for the distance and current running through it. That is why there are voltage drop calculators all over the web to size wire correctly.

[thastinger]

Please, both of you have been here too long dealing in extreme scenarios. I thought SK never replied to these for fear of liability anyway.

Here ya go OP

http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=2.061&voltage=13.4&phase=dc&noofconductor=1&distance=2&distanceunit=feet&amperes=75&x=97&y=13

this doesn't account for your connections though, just the wire. Anything close to the proper size for the Amps doesn't drop the dreaded 2% over a 2ft connection and you better not be using an analog VM or you'll never see that either.

[russ]

Please, both of you have been here too long dealing in extreme scenarios. I thought SK never replied to these for fear of liability anyway.

Here ya go OP

http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=2.061&voltage=13.4&phase=dc&noofconductor=1&distance=2&distanceunit=feet&amperes=75&x=97&y=13

this doesn't account for your connections though, just the wire. Anything close to the proper size for the Amps doesn't drop the dreaded 2% over a 2ft connection and you better not be using an analog VM or you'll never see that either.

Mod note - Watch yourself and the smart mouth - one warning