Battery cutoff switch when on shore power?

[cardtarget]

Hey all, just upgraded from a 2002 Coachmen to a 3170 Sunseeker (2014). Definitely some differences in how things operate that are confusing.

On my old rig the battery disconnect shut off all 12V items even when plugged in, so it had to be on if you wanted to use lights, fans, etc. In the sunseeker this doesn't seem to be the case as those 12V items operate even when the battery switch stays off when we're plugged into shore power. My question is, where should it be when we are plugged in? Will the battery charge if the disconnect switch is off?

Two semi-unrelated questions about the 3170:

Do the house batteries charge off the alternator when the vehicle is running?

There is an on/off switch next to the mirror controls on the driver's side. what is that for?

[emm-dee]

All your 12 volt items are being powered by the converter. The battery must be connected in order to be charged by the converter. However, the converter alone is not capable of putting out enough amperage to run high amp draw items like slide outs so it is necessary to have the battery online to provide the power needed to run those high amp draw items.

[DieselDrax]

The battery cutoff switch is so you can easily and quickly disconnect the battery for storage or if you need to perform service on a 12v device (shore power needs to be disconnected or converter off as well). The battery cut off is not meant to be used when switching between battery/12v power and shore power, you want to leave the battery connected all the time except for things I mentioned above.

[Witch Doctor]

Originally Posted by DieselDrax

The battery cutoff switch is so you can easily and quickly disconnect the battery for storage or if you need to perform service on a 12v device (shore power needs to be disconnected or converter off as well). The battery cut off is not meant to be used when switching between battery/12v power and shore power, you want to leave the battery connected all the time except for things I mentioned above.

This is correct, my question is why the op wants to disconnect his batteries on shore power? It is also my understanding that your alternator will feed your house batteries also, but really at only a trickle type charge, your alternator senses your coach battery for out put volts not the house, so your best to leave the disconnect open when on shore power. Could be wrong but I don't think so. Now if your on your generator, it will only charge your house not the chassis, but you might have a emergency start button that will use your house batteries to start the motor. So you always want the house to full charge. Don't use the disconnect except in storage with no electric connected. I'm sure I'll be corrected if wrong...happy travels

[Duckogram]

Not all units are wired the same so the best answer is:
Put a meter on your battery at rest, switch off, shore power disconnected.
Start your engine. Any change on the meter?
Yes=It charges off your Alt.
No, turn switch on.
Any change on the meter?
Yes=It charges off your Alt.
No= It does not. (there is a fix for that)
Shut your engine off.

Turn switch off then plug in shore power.
Any change on the meter?
Yes= It charges with switch off.
No = It does not.
Turn switch on.
Any change to the meter?
Yes= All is well.
No=Your Charger is not working.


The switch by the mirror controls is for the heater(s) in the mirrors.

Edit: x2 for what Diesel said.

Edit2: Welcome to the FRF

[Witch Doctor]

Like this, pretty good test if you have a meter, simple. Simple is good.

Originally Posted by Duckogram

Not all units are wired the same so the best answer is:
Put a meter on your battery at rest, switch off, shore power disconnected.
Start your engine. Any change on the meter?
Yes=It charges off your Alt.
No, turn switch on.
Any change on the meter?
Yes=It charges off your Alt.
No= It does not. (there is a fix for that)
Shut your engine off.

Turn switch off then plug in shore power.
Any change on the meter?
Yes= It charges with switch off.
No = It does not.
Turn switch on.
Any change to the meter?
Yes= All is well.
No=Your Charger is not working.


The switch by the mirror controls is for the heater(s) in the mirrors.

Edit: x2 for what Diesel said.

Edit2: Welcome to the FRF

[cardtarget]

Originally Posted by Witch Doctor

This is correct, my question is why the op wants to disconnect his batteries on shore power?

I don't want to disconnect the batteries... I just wasn't sure if the switch was a true disconnect switch (like my old one).

Got it, keep switch on all the time when using the RV. Thanks all. I will do that charge test soon... good easy instructions. Thanks.

[Garrette]

More info, in the event your Coach battery is weak and needs a boost, there is a momentary push switch on the left side drivers seat, down low, to jump start the coach using the house batteries.
The genny starts from the house batteries. If the house batteries are weak, start the coach as it will charge the house batteries a bit that will enable the genny to start.
If you start the genny and no power, there is a 30amp breaker in the genny, to the right and on the side of the mount for the prime/start switch. Can be a bit difficult to see.

[Splitshaft]

Originally Posted by cardtarget

On my old rig the battery disconnect shut off all 12V items even when plugged in, so it had to be on if you wanted to use lights, fans, etc. In the sunseeker this doesn't seem to be the case as those 12V items operate even when the battery switch stays off when we're plugged into shore power. My question is, where should it be when we are plugged in? Will the battery charge if the disconnect switch is off?

I can tell you about my 2018 Sunseeker, it works like your 2002 Coachman. And my Sunseeker batteries are recharged from the 220amp engine alternator to include the alternator powering the entire coach section when the engine is running. The Forest River Battery Control Center built by Precision Circuits Inc, for Forest River, is an amazing device if you have one. Not only does the Forest River Battery Control Center allow the engine alternator to charge the coach batteries without overcharging them, it also allows the coach converter to charge the chassis (engine) battery, without over charging the chassis battery as it will automatically disconnect to prevent overcharging.

I am really amazed with the engineering and simplicity that has gone into the Forest River Battery Control Center. In fact, as long as chassis battery voltage remains high, it keeps the chassis battery connected to the coach batteries even when the engine is not running. Not like it is possible to use much power from the chassis battery before the Forest River Battery Control Center disconnects the chassis battery, yet it does supplement somewhat coach power after a driving event. There are also fuses in the Forest River Battery Control Center for items that should be disabled when the chassis engine is running so the awning, slides, or other items do not get powered and extend driving down the highway.

If your coach was bought used, its electrical system may have been modified by the previous owner. I always keep my battery cutoff on the on position as I desire for my Progressive Dynamics, four stage converter, to keep my coach and chassis batteries maintained for the longest life. It seems to me a lot of positive changes have been made to the 12V systems of RV's recently I find to be a major benefit.