Roadtrek why battery connect before shore power

[tkubaska]

2012 SS Agile.

I have been cautioned to always turn on the Battery Disconnect switch BEFORE connecting to shore power.

There is even a cautionary sticker that Roadtrek put in my coach. It reads …
“The battery disconnect switch on the monitor panel must be in the “ON” position prior to connection to an outside electrical source.”

And I, of course, have always followed that instruction. But I have never heard a good explanation (I have heard some) of why that is necessary.

I have had people say that “batteries must be on before connecting to shore power so that the batteries will charge.” But that seems to say that batteries must be on when shore power is connected, not necessarily that they be on before connecting to shore power.

Does anyone have an answer to this?

Thanks.

[hbn7hj]

Yep, so you can see the light come on. Once shore power is connected the light is on even if the battery is not connected and able to charge.

[BBQ]

Originally Posted by tkubaska

2012 SS Agile.

I have been cautioned to always turn on the Battery Disconnect switch BEFORE connecting to shore power.

There is even a cautionary sticker that Roadtrek put in my coach. It reads …
“The battery disconnect switch on the monitor panel must be in the “ON” position prior to connection to an outside electrical source.”

And I, of course, have always followed that instruction. But I have never heard a good explanation (I have heard some) of why that is necessary.

I have had people say that “batteries must be on before connecting to shore power so that the batteries will charge.” But that seems to say that batteries must be on when shore power is connected, not necessarily that they be on before connecting to shore power.

Does anyone have an answer to this?

Thanks.

It has to do with the ATS/inverter-charger.
If the battery is not ON,
the system might not be able to see the incoming AC power.

[booster]

Our 07 C190P Roadtrek had that sticker also, but it was totally false. The earlier versions where they used isolators seemed to be the ones that needed the switch on to charge. It had nothing to do with the ATS or charger, but only to where the charger was connected. In the early versions, the charger was on the coach side of the power relay, and on the later ones like ours the charger was connected to the battery side of the power relay.


By 2012, they may have changed again, but I would not go just by the sticker, as I know they have been wrong in the past.

[Bud]

tkubaska, simple enough to know if you need the battery switch on or not. Give it a try, please let us know what you find.

Bud

[Nic7320]

The battery is necessary to maintain voltage regulation. Without a battery, the voltage output of the shore power converter will go much higher than when a battery is properly connected. All of your 12 volt appliances can be damaged by a higher voltage.

[booster]

Originally Posted by Nic7320

The battery is necessary to maintain voltage regulation. Without a battery, the voltage output of the shore power converter will go much higher than when a battery is properly connected. All of your 12 volt appliances can be damaged by a higher voltage.

While the above is true for many chargers, the disconnect switch the OP appears to be asking about would be the one that connects the batteries to the coach, as Roadtrek doesn't normally put in a full battery disconnect switch that totally disconnects the batteries from everything. If the charger is connected on the battery side, like it was in our 07, then it would initiate and regulate whenever it was on because it was always connected to the batteries.

[booster]

I have had these markups laying around for a long time as this used to come up a lot. They show the different charger connections for 2003 vs 2008 on the Roadtrek wiring diagrams.

[booster]

The 2012 owners manual on their webstie does have a wiring diagram for a 2012 Agile and it shows the inverter/charger connected to the battery side of the 12v power relay.


That should indicate that the batteries will be on charge whenever the van is plugged in to shore power, and it won't matter if or when the 12v power switch is turned on or off.


http://www.roadtrek.com/download/1572&file_id=1570


Page E7