Wiring Diagram Review

[John61CT]

The better quality ones specify cycle lifetime.

Much longer if currents are low while switching.

Cheap ones aren't reliable.

Selecting the right type, delay specs etc is a lot more complex than fuses.

Very expensive at high amps.

 

[dgshelto]

I have 3 6AWG wires running to my aux battery + post: Inverter (60A), Fuse Block (60A), and keyline battery isolator (150A). My battery has screw-in terminal posts (basically an M8 bolt). Is it ok to just connect all 3 wires to the post with ring terminals? 

I attached a picture depicting what I'd like to do.

 

[John61CT]

Better to run to a buss bar.

But stacked no more than 3, maybe 4 max.

And all direct on top of the batt post base, nothing in between.

Make sure fully parallel and flat, max surface area contact no gaps between.

Regular inspections for sure.

Maybe a thin coating of NO-OX-ID conductive grease between.

 

[dgshelto]

Better to run to a buss bar.

But stacked no more than 3, maybe 4 max.

And all direct on top of the batt post base,  nothing in between.

Make sure fully parallel and flat,  max surface area contact no gaps between.

Regular inspections for sure.

Maybe a thin coating of NO-OX-ID conductive grease between.

So the ring connectors don't need to be separated by nuts? Just stack em / fasten them down to the base?

 

[Scout]

I also read it's a good idea to put the thicker higher amperage terminals toward the battery so high amps doesn't go through the smaller ones first.

 

[Weight]

It is better practice to use a bus bar. That picture is "How to Not Connect to Battery". You can reasonably make three cables fit the stud. Right, you put the heaviest at the battery then each is the lessor amps. Get rid of all those nuts! Battery - Cable - Cable - Cable - Flat washer - Lock washer - Nut. Then= Torque the nut to specifications, (110 inch pounds). Each cable needs a fuse close to the battery positive!

 

[Weight]

Correction, instead of a stud and nut, you will have a bolt into the battery. Same rule, no washers or nuts between any cable and the battery, use a lock washer and torque to specs. Still better use a bus bar.

 

[dgshelto]

Correction, instead of a stud and nut, you will have a bolt into the battery. Same rule, no washers or nuts between any cable and the battery, use a lock washer and torque to specs. Still better use a bus bar.

Thanks for the feedback, that's what I'll do.

 

[John61CT]

So the ring connectors don't need to be separated by nuts? Just stack em / fasten them down to the base?

Not only don't need to be, but should not have stuff in between creating extra resistance.

But the 100% contact, quality terminators etc are important.

As I said, better to run to a nearby buss. So much easier to add more connections as you will need to anyway.

 

[dgshelto]

Not only don't need to be, but should not have stuff in between creating extra resistance.

But the 100% contact, quality terminators etc are important.

As I said, better to run to a nearby buss. So much easier to add more connections as you will need to anyway.

If I add a bus, do I size my wire that runs from the bus to the + bat terminal to handle the combined amperage of the 3 accessory wires on the bus (60A + 60A + 150A)? Or can I throw my leftover 6AWG on it?

For what it's worth, all hot wires are fused close to the bat.

 

[Weight]

Depending on the temperature rating of the cable insulation, 6 awg can handle about 100 amps safely. What wire are you using? I use marine grade which is rated at temperature of 105C and 6awg is rated up to 120 amps outside engine spaces. That doen't mean it will not have voltage drop, but it will not catch fire. Wire needs sized by amperes and distance.

 

[John61CT]

No, I would size for the greatest total current you can imagine using from the bank at a given time.

Too easy to just add stuff later and not bother (or even remember) the upstream connection.

Or if you size the master bank-side CP to say 85% of that wire, that would work.

 

[dgshelto]

Hey guys, been on the road for the last month and everything has worked out great-ish.

Question: when planning on working on the system, it's difficult for me to remove the hot wires from the batt terminal without causing sparks. Should I remove the fuses to the wires prior to removing the wires from the batt terminal to prevent this? Or should I treat it like my car batt and remove the single negative wire from the neg batt post first to open the system?

 

[Canine]

The reason it is sparking is something is on. But you may not be able to avoid that. DC arcs and sparks a lot and you likely won't be able to avoid it entirely. I put in switches for my solar panels and charge controllers. Pulling the fuses first could help. If you have ten small items on and pull each fuse, you will avoid a larger spark when disconnecting the batteries. Having all the fuses in one fuse box will make that job easier instead of inline fuse for each wire. To minimize spark, disconnect the negative wire first, then when reconnecting, do it in reverse and connect the negative wire last just like a car battery.

 

[dgshelto]

The reason it is sparking is something is on. But you may not be able to avoid that. DC arcs and sparks a lot and you likely won't be able to avoid it entirely. I put in switches for my solar panels and charge controllers. Pulling the fuses first could help. If you have ten small items on and pull each fuse, you will avoid a larger spark when disconnecting the batteries. Having all the fuses in one fuse box will make that job easier instead of inline fuse for each wire. To minimize spark, disconnect the negative wire first, then when reconnecting, do it in reverse and connect the negative wire last just like a car battery.

The sparking is minimal, I'm just trying to find a good way to avoid it as much as possible. Thanks for the reply Canine.

 

[Weight]

ALWAYS disconnect the negative battery terminal first and before working on the system. A battery disconnect on the negative allows me to shut every thing down without any tools or torque wrench.

 

[John61CT]

A master isolation switch is good to have anyway, convenient when leaving the van unused for a while, IMO required for safety with a large House bank.

Ideally mounted where you can get to it quickly in an emergency, but where no one will play with it.