Wiring for battery monitor with inverter

[Mattirs]

Originally Posted by gator.bigfoot

Some other factors to consider. This one is on interconnecting batteries. But there are many other great pieces of info on this website.
http://smartgauge.co.uk/batt_con.html

Been using their Smartgauge for a year 1/2 now, and I love it.

[gator.bigfoot]

Originally Posted by uncle_bob

Hi

What is far closer to perfect are the crimpers made by people who sell lugs. Buy their ($$$$$) crimper and their ($$$$$) lugs, use them together. If you do this sort of stuff for a living, spending $250 or a good tool is not a big deal. The cost of the lugs gets passed on to the customer.

Indeed you can detect a gross under crimp pretty easily. Tug it and it comes apart. An over crimp is a bit harder to spot. In both cases, what you can "inspect in" is not the whole story. Without x-ray vision you can only spot just so much.

Bob

You'll need a lot more than $250 on a high end crimper. Who are you kidding? For anything under AWG 1 the cheaper models suffice. At work our crimpers are in thousands.

If your unsure take a crimped connection and saw it in half and take a look at the crimp it should still hold and be crimped properly. For the smaller wires I use the cheaper crimper and put 2 crimps on it. One further forward and the other further back. That way this is no chance of failure. If I need something larger crimped I'll borrow the ones from work.

[uncle_bob]

Originally Posted by gator.bigfoot

You'll need a lot more than $250 on a high end crimper. Who are you kidding? For anything under AWG 1 the cheaper models suffice. At work our crimpers are in thousands.

If your unsure take a crimped connection and saw it in half and take a look at the crimp it should still hold and be crimped properly. For the smaller wires I use the cheaper crimper and put 2 crimps on it. One further forward and the other further back. That way this is no chance of failure. If I need something larger crimped I'll borrow the ones from work.

Hi

This one:

https://www.alliedelec.com/thomas-be...iABEgI1Q_D_BwE

Is the cheapest thing that I'd say is significantly better than the Amazon $50 stuff.

Bob

[SabaRocks]

Thanks for the detailed response and information, gklott.

I will see if I can track down those two references. I am one of those that likes to fully understand these systems and requirements while making changes. Maybe that comes from years tinkering on boats.

You are right in that I did not draw the fuses or breakers in my diagram and that it does need them. It was mostly for the illustration of what to do with the wires between the battery and the shunt. I have to imagine this is installed correctly as-is now as it is all factory installed (big assumption?). I'll track all that down to verify before making any changes.

We have the WFCO 1000W inverter and it's manual recommends a 100A inline fuse and #4 wire. That's why I was figuring on that load being the 100A.

Sounds like the 1 wire solution is the safest route to take. I like sleeping not having to worry about this stuff. I'll look at what it takes to rerun a bigger wire. Luckily, running wire on an Airstream looks easier than a boat! If I size the system for 150A, it looks like that wire size may need to be 1 AWG from the following (the only ABYC E-11 PDF I could find was older and only covered up to 100A).

https://www.bluesea.com/support/arti...r_a_DC_Circuit

[gklott]

Originally Posted by SabaRocks

Sounds like the 1 wire solution is the safest route to take. I like sleeping not having to worry about this stuff. I'll look at what it takes to rerun a bigger wire. Luckily, running wire on an Airstream looks easier than a boat! If I size the system for 150A, it looks like that wire size may need to be 1 AWG from the following (the only ABYC E-11 PDF I could find was older and only covered up to 100A).

Your years tinkering on boats will pay off with your RV electrical work. Hope the wire run is easier for you.

As described before, as long as your primary wire is 105C rated, and not bundled with more than 3 wires, you can use 2 AWG for the 150A. 1 AWG stranded 105C is HARD to find. I got my 2 and 2/0 AWG Ancor UL 1426 listed, 105C battery cable from PKYS and Amazon.

Have you considered building in a bit of future capacity - such as going to a 2 kW inverter? If so, now is the time to do it. That would take you to 2/0 or larger.

fran&frank had a good suggestion. For this few wires, you can get PKYS or West Marine to make up cables using Ancor UL-listed wire, Ancor UL-listed lugs, and Ancor heat shrink.

73/gus

[uncle_bob]

Hi

These days, insulation does not stop at 105C. You *can* get even higher temperature ratings. The issue then is not so much the wire as what's it's in contact with. Aluminum or wood are probably ok above 105. Plastics .... maybe not so much ....

It's a good bet that whatever you are running the wire *into* also has a temperature rating. It likely has plastic bits here and there. It may not be as easy to check the rating on it as it is to read the markings on your wire....

Bob

[gator.bigfoot]

Originally Posted by uncle_bob

Hi

These days, insulation does not stop at 105C. You *can* get even higher temperature ratings. The issue then is not so much the wire as what's it's in contact with. Aluminum or wood are probably ok above 105. Plastics .... maybe not so much ....

It's a good bet that whatever you are running the wire *into* also has a temperature rating. It likely has plastic bits here and there. It may not be as easy to check the rating on it as it is to read the markings on your wire....

Bob

The temperature rating of a conductor is a maximum temperature, at any location along its length, that the conductor can withstand over a prolonged period of time without serious degradation. The wire can heat up to this temperature depending on the amperage being put through it, but does not mean it will run at this temperature. The hotter the wire runs the shorter the life of the wire due to the polymer breakdown of the insulation known as the Arrhenius Relationship.

If the wire is hooked into lugs or circuit protection that is not also rated to it's wire rating then the entire circuit needs to be derated to the minimum temperature rating (usually 60C) of the other items in the circuit according to NEC rules.

You will find that at maximum continuous operation you will not hit the max current specified in the circuit. The max current rating is for the peak output of all the devices for a short period of time. That is what the max rating of the circuit is for and that is what the circuit wire has to be designed to withstand since that is what you are fusing it to.