Battery Disconnect Switch

[Iceman31]

Ok stupid question. Our new trailer has a battery disconnect switch. This morning we had a power outage. My battery is dead. I had the switch in the on position which I thought was correct. Should it actually be off in order to allow the battery to charge? I have never had one of these switches in any other unit I have owned.

[fj12ryder]

I would say you did it correctly and have another problem. You need to check the voltage coming out of your inverter, or if there even is voltage, to the battery when you're plugged into shore power.

[Iceman31]

Yes RV has been plugged into shore power since I took possession in June. The reason I say on or off is because that is what it says on the red knob. You turn it to green which states on or red which states off.

[beemerphile1]

First, prior to power outage, was the RV plugged into shore power?

Second, a disconnect may need to be open to charge and maybe not. In my trailer the switch disconnects loads but not the battery thus it can charge in either position.

Third, all confusion disappears when the switch is referred to as open or closed rather than off and on. Technically a switch is not off/on it is open/closed.

[John_Wayne]

If you don't have a good 3 stage converter/charger and the trailer is hooked up 24/7 it could be the converter has boiled the water out of the battery and the battery is dead. How often do you check the battery water level???

[Iceman31]

Trailer is brand new - delivered in June - have a seasonal site and have always been hooked up to power. Power outage this morning and had no 12 volt at all. Will have to check into it when I am done work.

[MrWizard]

Battery has to be connected to the trailer
For it to stay charged
For it to power the 12v system when shore power and converter shut down
Disconnect the battery only when the trailer is in storage
Or you are working on the wiring

You may need a new battery, it might not regain its health
Depending on how long it has been sitting there dead

[maddog348]

2oldman ~~ Thnx ~~ Double negatives always give me a headache.

[2oldman]

Easier to understand if you think 'battery connect switch.'

[fj12ryder]

Depending on the "battery disconnect" switch, it may not shut off all power to the trailer. So even if it is "Off" you can still be drawing power from the battery. Install your own battery disconnect switch and then you'll be sure you won't find your battery drained again.

[azdryheat]

Battery disconnect means just that, disconnected. It won't charge or discharge when turned off unless there is wiring that bypasses the disconnect switch.

[BFL13]

On shore power, the switch should be "closed", which means the converter can charge the battery. If the switch is "open", the battery cannot run the 12v things when the converter loses its 120v input.

The battery being "dead" needs clarification. Low voltage at the battery posts using your digital multimeter? Or just no 12v in the rig now there is no power to the converter and the disconnect is open?

There is also a battery fuse or DC breaker near the battery on the pos side that could have blown (to open) that would have the same effect inside the rig as if the disconnect were open.

[pianotuna]

iceman31,

The switch needs to be on for charging to happen.

[BB_TX]

If I remember correctly, you can pull the handle out of the switch when the battery is disconnected but not when the battery is connected.

[Optimistic_Para]

Just off the top of my head, either they've wired the converter output directly to the battery, in which case it shouldn't matter which way the switch is set, or they've wired it through the switch, in which case it would need to be ON in order for the battery to be charged.

Sounds to me like you have a problem other than the switch.