Battery Disconnect 2

[gbkims]

I'd insure the switch was ignition protected in case of flammable vapors/gases.
You'd think the OEM switch with the contacts on the opposite side of the wall opening from the Key would do this, but I don't know what the specs are.
The Blue Sea & Perko switches state they are ignition protected, Meets UL 1500 and SAE J1171 external ignition protection requirement

The image of a switch used to disconnect an inverter than can have inrush current causing contact arcing comes to mind.


Edit: Ignition Protected https://www.bluesea.com/support/arti...n_Your_Boat%3F

Ignition protected devices are designed in such a way that:
they won't ignite a surounding air-fuel mixture if there is an explosion inside them.
they can't reach a high enough surface temperature or generate enough spark to ignite an air-fuel mixture.

[2825Matheny]

Good call to want a battery disconnect that actually isolates the battery. Been there, done that too.
In addition to redoing the disconnect, I had a couple of other objectives too. Clean-up the wiring, upsize wire sizes for some circuits, remove and replace all auto-reset circuit breakers with AMI fuses, add an ATC fuse block to replace the "rats nest", and move the converter from the basement to the front compartment. I also added two power meters. One to monitor the output of the converter, the 2nd to monitor all of the 12-volt power used by the RV.
And in the process I learned the "rats nest" in the pin box for the 7-pin plug had "issues" so I upgraded that with a terminal block too.

[Country Campers]

So another question concerning the battery disconnect. On my camper the battery is on the street side, disconnect on the curb side. The battery juice runs from one side to the other and then back to circuit breaker strip. Is this reducing the amps put out by the battery? Forgive me, I am weak with this stuff.
Would moving the disconnect right by the battery be beneficial?

Brian

[Calbar]

So another question concerning the battery disconnect. On my camper the battery is on the street side, disconnect on the curb side. The battery juice runs from one side to the other and then back to circuit breaker strip. Is this reducing the amps put out by the battery? Forgive me, I am weak with this stuff.
Would moving the disconnect right by the battery be beneficial?

Brian

This will reduce the voltage that gets to the 12V system with the extra length of wire and the resistance of that wire. It would be best of the cutoff switch was on the same side as the battery and the circuit breaker strip. Always best to keep the wires as short as possible. 12V DC systems are really susceptible to wire length and voltage drop. Much more than household 120V AC systems.

Rob

[howson]

Q: Is this reducing the amps put out by the battery?

A: Technically, no. It changes where the battery capacity is used. The battery doesn't care where the resistive load is in the circuit. A longer (and/or smaller) wire means your wires are "seen" as a larger load (using battery capacity) than a shorter, larger wire.

Q: Would moving the disconnect right by the battery be beneficial?

A: Depends on the existing wire size and the loads you are running through it, Brian. For short runs with low amperage you won't get any tangible benefits, but in general shorter runs in a 12V system are desirable.

Blue Sea has a good chart here: https://www.bluesea.com/resources/1437 (Rob has posted this link in other threads.) Here's another one: https://www.westmarine.com/WestAdvis...e-And-Ampacity

[sande005]

Anybody have comments about this style battery switch? https://www.amazon.com/LotFancy-Batt...motive&sr=1-27

Thinking about putting one on the jumper between my soon to be 2 6v batteries.....
I'd leave the factory "non-shutoff" switch in place, and the new one would be for times when the trailer goes into longer storage.

[Luv2Ski]

Anybody have comments about this style battery switch? https://www.amazon.com/LotFancy-Batt...motive&sr=1-27

Thinking about putting one on the jumper between my soon to be 2 6v batteries.....
I'd leave the factory "non-shutoff" switch in place, and the new one would be for times when the trailer goes into longer storage.

I just installed two 6v golf cart batteries in series and was going to do the same interrupted jumper thing when the Moeller GC2 battery box comes in. Since the batteries are flooded lead-acid, I want to be sure the box is properly ventilated. I’ll reuse the front intake vent and floor exhaust port from the original 12v house battery box to that end. Once that’s done, I’d like to put the switch you linked (or this one) on the outside of the battery box. Hopefully the only time the lid comes off will be when I’m checking electrolyte levels or putting the batts away for the winter.

[sande005]

I just installed two 6v golf cart batteries in series and was going to do the same interrupted jumper thing when the Moeller GC2 battery box comes in. Since the batteries are flooded lead-acid, I want to be sure the box is properly ventilated. I’ll reuse the front intake vent and floor exhaust port from the original 12v house battery box to that end. Once that’s done, I’d like to put the switch you linked (or this one) on the outside of the battery box. Hopefully the only time the lid comes off will be when I’m checking electrolyte levels or putting the batts away for the winter.

Since mine is an Imagine, I'll have to have the box or boxes out on the tongue. But not so much worry about proper venting. I'm considering the switch I linked to, primarily because it looks like it will fit easily under the lid of a box. Probably not as weather resistant as the marine style others have linked to. But easy enough to by-pass if it corrodes apart.

BTW - If you are in the "Rocky Mountain West", do a search for battery self-discharge here. I posted a graph showing how long it takes batteries to do so. You should have absolutely no issue just fully charging them, disconnecting fully, and leaving them in the trailer all winter. No sense wrestling those beasts if you don't have to.

[Country Campers]

I have noticed today, after doing the disconnect relocation, that the red/white wire on the second from right breaker bottom post is the charge wire for the battery coming from the tow vehicle. The way I left it wired and traveling with the disconnect turned off I was not getting vehicle charge voltage to the battery. I moved this wire over to the bottom post of the far left breaker. This will allow for the disconnect to be off and the vehicle to charge the battery. So today was a learning day.

Brian

[akcooper9]

I have noticed today, after doing the disconnect relocation, that the red/white wire on the second from right breaker bottom post is the charge wire for the battery coming from the tow vehicle. The way I left it wired and traveling with the disconnect turned off I was not getting vehicle charge voltage to the battery. I moved this wire over to the bottom post of the far left breaker. This will allow for the disconnect to be off and the vehicle to charge the battery. So today was a learning day.

Brian

Brian great post. Do you have an updated picture of this change?

This is on my list of things to do!