Battery Disconnect - Knife Switch?

[Atlanta Panther]

From an old thread responding to someone who suggested removing the batteries during the winter and putting them on a trickle charger:

"Originally Posted by MNtraveler
You can remove them, but it's really not necessary (and can be a negative as discussed below).

What is necessary is to disconnect the batteries so there is no trickle drain on them from items like the radio memory or CO/LPG detector. This is done with a battery disconnect switch installed on the negative or ground side of the battery combo (be sure it's the ground line that covers both batteries so you don't leave one connected).

You can use one like this, although the exact model that will work for you depends on what kind of batteries you have (how the terminals are set up - top vs. side - and how the ground wire is attached):

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

We have left ours outside in Minnesota where it can get to -20 or worse and not had any problems and almost no battery drainage when disconnected. Just stop by now and then, CONNECT the batteries, fire up the generator and run it at at least 50% load to exercise the generator and keep it from gumming up. If you remove the batteries, you will not be able to even start the generator. The generator will not only top up the house batteries but also top up the engine/chassis battery too (based on how the Battery Control Center works). So you will kill 3 birds with one stone. The 50% load can be applied using an electric space heater (with no more than a 15 amp load to the plug socket circuit), which will also keep you warm while you sit there watching TV or catching up on email, or run the electric convection oven if you have one set to 350 or 400 degrees. Exercise the generator for a good hour.

From Mark Polk, prolific author of RV Education 101: "The first thing you need to understand about maintaining your generator is that they need to be exercised on a regular basis."

My question is - Why do you need a knife switch? Couldn't you use the round battery disconnect switch on the left side by the stairs when you come in the door?

Actually, I plan to leave mine plugged in to my 30amp hookup I specially made for the SS during the winter months. Does anyone see anything wrong with that as long as I periodically exercise the generator? Does it matter whether I have the round switch by the stairs so the batteries are connected or not?

[A32Deuce]

That does not turn everything off. A blade switch or disconnecting the battery terminal will disconnect the batterys. There are thing connected to the battery that don't go off when you turn that switch off.

[Atlanta Panther]

So I guess things like the generator and propane detector are wired directly to the batteries bypassing the switch which is why you need the knife disconnect.

I understand, now. Thanks for the help.

Do you see anything wrong with me just leaving it plugged in over the winter months?

[A32Deuce]

Originally Posted by Atlanta Panther

So I guess things like the generator and propane detector are wired directly to the batteries bypassing the switch which is why you need the knife disconnect.

I understand, now. Thanks for the help.

Do you see anything wrong with me just leaving it plugged in over the winter months?

No. As long as you check the water level in the batterys, you should be ok.

[Larry-NC]

Originally Posted by Atlanta Panther

My question is - Why do you need a knife switch? Couldn't you use the round battery disconnect switch on the left side by the stairs when you come in the door?

Did you really mean a knife switch? I haven't used one like that since projects in seventh grade? There are lots of other shapes and styles that are more convenient. Some even mount directly on the battery.

Here's a picture of a good old-fashioned knife switch.

Larry

[AbdRahim]

A knife switch in place of rage round one will still not disconnect items wired directly to the battery (bypassing the switch).

[babock]

I would prefer to put in a round disconnect switch that actually turns off all battery power.

[JLeising]

I have seen knife switch battery terminal disconnects. My concern with them is the possibility of a spark that close to the battery vents when engaging or disengaging.

https://www.amazon.com/WirthCo-20148...Q6L&ref=plSrch

[Scrapper]

Like others have said the battery disconnect switch will not remove all devices from the batteries. But, you can install another disconnect in the circuit near the batteries. You can install it on either the positive or negative lead.

If you install it on the positive lead you must place it between the batteries and the junction box or resetable fuse on the frame where other distribution wires connect to the positive lead.



For those reading this who have a trailer, just remember that the break-a-way switch is usually connected to the always hot side of the resetable fuse.

[A32Deuce]

If you are only using it to shut down all battery drain, then where you put the cutoff doesn't matter if all battery power is off.