Battery Monitor Installation Question

[padlin]

I was thinking going with these.

You can get them here at a somewhat reasonable price.
Blue Sea Systems 5185 Terminal Fuse 150 Amp

[Brian B-P]

Originally Posted by padlin

I was thinking going with these.

You can get them here at a somewhat reasonable price.
Blue Sea Systems 5185 Terminal Fuse 150 Amp

A FiberglassRV member (Roy in TO) used these. It looks like a solid, effective, and tidy setup.

[WestEnder]

Fuses are there for two reasons.
1. To protect equipment
2. To protect the wiring

The fuse on your Trimetric's wiring harness is there to protect the Trimetric (equipment). Inverters, etc will have their own requirements for fusing according to what will protect that individual piece of equipment. The installation guide for the equipment will specify what kind of fuse to use.

The catastrophe fuse is there for reason 2. It is to protect the wiring. If there is a short circuit, a huge amount of current can come through the wire. This will cause it to get very hot. In the worst case scenario that will start a fire.

This video shows why you should be concerned about protecting the wiring: Short Circuit Car Battery on Vimeo

Imagine that happening in your Escape.

Another point to be made from the video is that wires that are too small for the amount of current will overheat. If the temperature rises above the melting point of the insulation, the insulation will melt. When the insulation melts, the wires can touch something they shouldn't. If that happens to be something else that carries current, like another wire or anything metal that is grounded, you can then get a short circuit and fire. Good quality wiring has the temperature rating of the insulation printed on it. You can use a table to look up what size of wire, with what kind of insulation, is needed to carry the amount of current you need to carry. Search "ampacity" for more.

Catastrophe fuse location. In a DC circuit it is on the wire from the positive side of the battery or on the positive battery terminal. If connected by wire make it the first thing on the wire after the battery and use the shortest wire possible. You don't want the possibility of a short between the catastrophe fuse and the battery. That would be really bad. If the fuse is further from the battery you have the potential for the cables or something metal rubbing from road vibration and damaging the insulation thus causing a short circuit right in the battery compartment.

Standards? Well there are lots of those, and which country you are in matters. You will need to figure out what applies in your situation. Google will be helpful there. I suggest being conservative and going closer to the battery rather than further away. I'm planning on using the ISO/ABYC recommendations of ~7" or less if possible in my own trailer. That's more conservative than other standards that might apply better but I prefer to be conservative in this case. Your situation may vary.

Which fuse? You need to look at the size and type of your wires and how much current you will need to carry in that main battery cable. For most of us it is probably with a full load on a large inverter (for example, you might run a hairdryer on a 1500W inverter as your heaviest load). Add a little extra for stuff like the lights. Size your fuse (and cables!) for that. Depending on how you have equipped your trailer and what kind of electric stuff you like to run it will be different for everyone. It needs to be small enough to keep whatever wiring you have safe and big enough that it doesn't blow when a whole bunch of stuff gets turned on in the trailer. You want it to blow when there is a need, not routinely under normal use.

There is a good article here that explains it better than I can. Battery Bank Fusing Photo Gallery by Compass Marine How To at pbase.com

As far as I know, the Blue Sea fuses are very good. Their marine rated, ignition protected fuse that you have there gets some very good reviews. Ignition protected is good because of the hydrogen gas (from the battery) in the battery compartment. Enough of the people I respect use it that it will be my choice when I get my Escape. They make it in a multitude of sizes so you can pick the size you need.

[WestEnder]

Looking at this after some sleep, I realize I should have said: size your cables for the total load then size the fuse to the cable specifications (size, temperature rating). This will give you your maximum fuse size. It is safe to go lower.

[sturski]

Timely topic for me. My build is late enough to steal freely from this discussion.

[WestEnder]

It's weird how seldom some of this gets discussed on RV forums. Wire size in relation to voltage drop is a common topic but not wire size in relation to safety or fusing.

[padlin]

Here's one of the better charts I found for selecting wire, fuses, and fuse holders.

http://assets.bluesea.com/files/reso...ence/20010.pdf

The pdf at the link is better to view then the attached .jpg

[gocamp]

From post #4 in 2014

Does Escape still have a relationship with WeGoSolar on Vancouver island and all the items I order were never put on my charge card. Instead they were added to my build sheet as a part of the total package? I was asking to order the popular Trimetric 12V battery monitor that is so popular with previous Escape owners. Thanks.

[cpaharley2008]

If it is part of the option then Escape adds to build sheet, anything after market you can add later, after delivery.

[gocamp]

The Trimetric is not offered as a build sheet option is the reason for asking. In order to have the wires pre-run during build, from storage box, through shell, to cabinet location of your choice. But not the monitor itself installed. It was mentioned Escape will only pre-run the wires, and nothing else.

[cpaharley2008]

Did you ask Escape? They may be able to run the wires while in production for ease of install later?

[padlin]

It may have changed, but 2 years ago I had to send eti the cables to run, they did not provide them.

[fudge_brownie]

Like Bob, the folks at Escape would not install my Trimetric. However, they will run the wiring harness during their build process. I purchased the harness from WeGo on Vancouver Island and had it shipped to Escape. I never paid for the harness as it was on on my invoice from Escape. I just looked it up and I purchased the entire kit from WeGo, the harness, meter and 500 mA shunt.. After delivery I installed the Trimetric in less than 30 minutes and then spent the better part of three days figuring out how to program the thing.

[cpaharley2008]

Yes, I had installed 2 Trimetric meters on prior units, never really took advantage of all the features, all the settings would change after unplugging and storage. I can see it's value on a boat or a motor home that is in constant use, but I'm not missing it.

[stephen99]

Originally Posted by DonF

After reading that the shunt should be installed as close to the battery as possible, I chose to mount it on the battery case with 3M tape. I figured there was plenty of ventilation since the batteries are not in an enclosed box and corrosion won't be a problem; time will tell. I replaced the ETI cable between the battery posts with 4 gauge cable, the same size as cable from the inverter as well as using 4 gauge to connect from the shunt to the battery post. My local NAPA store cut the cables to the length I asked for as well as crimping on the end connectors to the cables.
Attachment 5924

I tried my local NAPA store and they don't make cables to length so I guess I need to order online. I am leaning toward the Victron battery monitor which has a bluetooth device so you can check numbers from your cell phone. I believe I need a 3/8" ring lug on the shunt end and 4 gauge wire but what about the battery end of the cable? Would that also be a 3/8" ring lug?

[fudge_brownie]

Yes, I tried my local auto supply stores for custom length cables and could not find one who did them. We have a chain called Batteries Plus, they might be a choice. I ended up purchasing from Amazon.

[Vermilye]

A good source for custom cables (as well as other electrical supplies) is GenuineDealZ. They will provide what ever length & ends you want, well crimped & covered with heat shrink.

As to cable size, it depends on the the size of your inverter. I have a 1000 watt inverter & the specifications for the Xantrex ProWatt SW 1000 call for #0 wire. Oversized for the maximum current draw of the inverter (around 100 amps at full load) but the larger cable helps prevent the inverter from alarming or shutting down from low voltage due to drop over the wiring.

[stephen99]

Originally Posted by Vermilye

A good source for custom cables (as well as other electrical supplies) is GenuineDealZ. They will provide what ever length & ends you want, well crimped & covered with heat shrink.

As to cable size, it depends on the the size of your inverter. I have a 1000 watt inverter & the specifications for the Xantrex ProWatt SW 1000 call for #0 wire. Oversized for the maximum current draw of the inverter (around 100 amps at full load) but the larger cable helps prevent the inverter from alarming or shutting down from low voltage due to drop over the wiring.

Thanks, Jon. I will be getting the 1500 watt inverter that ETI offers as an option. No idea of the make or model.

[slipspe]

Looks good! Any idea what size end connectors?

[MyronL]

These two battery monitors of mine seem off by .04