Battery disconnect on or off when on shore power

[Brutas]

I have been wondering: does it make any difference if you leave the battery disconnect switch on or off when you are plugged into shore power?

[Tha_Rooster]

If you turn it off nothing works no matter if it’s plugged including fridge. If your going to leave it turn it off.

[BCam]

It may depend on your make/model/year, but, in most cases, your battery switch needs to be on in order for your converter/charger (or inverter/charger as the case may be) to be online. This means that, if it's off, you won't be charging and won't have 12V power to your lights, etc.

[Old-Biscuit]

Battery disconnect is for Storage ....OFF in storage
Otherwise ON


AC Power provides means of charging/maintaining battery

[Outbound]

Ditto for on unless in storage.

[aether_one]

If you "disconnect" the batteries when plugged into SP they will not charge. All the DC loads will work though as the converter will supply the DC buss.

A good rule of thumb is to leave the batteries connected at all times EXCEPT when stored with no SP connected.

[FIRE UP]

Originally Posted by tfryman;4838212[B

]If you "disconnect" the batteries when plugged into SP they will not charge.[/B] All the DC loads will work though as the converter will supply the DC buss.

A good rule of thumb is to leave the batteries connected at all times EXCEPT when stored with no SP connected.

"....they will not charge...."
Wellllllllll, not exactly. It all depends on how the system was built and, whether or not it's a diesel coach or a gas and, what kind equipment is installed. For instance, our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP, DOES charge the house (and chassis) batteries with the House battery switch in the OFF position. Now, again, it's a diesel unit. But, I cannot speak for gas coaches as, it's been over 8 years since we've had one and, I cannot remember if it even had a house battery cut-off switch.
Scott

[twinboat]

Its not gas or diesel, in most cases, its Inverter/ charger OR converter/charger.

Inverter chargers charge thru the large inverter cables, often hooked directly to the batteries, bypassing the battery disconnect switch.

With converter/chargers, they power the 12 volt system at the 12 volt fuse/breaker center and back feed thru the disconnect to the battery for charging.

[AKIQPilot]

Originally Posted by FIRE UP

"....they will not charge...."
Wellllllllll, not exactly. It all depends on how the system was built and, whether or not it's a diesel coach or a gas and, what kind equipment is installed. For instance, our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP, DOES charge the house (and chassis) batteries with the House battery switch in the OFF position. Now, again, it's a diesel unit. But, I cannot speak for gas coaches as, it's been over 8 years since we've had one and, I cannot remember if it even had a house battery cut-off switch.
Scott

Yep. It all depends on what brand and model coach you have. Our gas powered Winnebagos also charge the batteries and run all the systems even with the coach battery disconnect switch in the Off position.

There are just too many different configurations to give a perfect answer to the OP. Some coaches need the coach battery switch in the on position when plugged in to shore power and some don't.

Neither of my coaches need the coach battery switch on to operate properly when plugged in to shorepower. .

[richard5933]

The question of whether or not your batteries will still charge depends on which side of the disconnect switch your charger is connected to. Our charger is connected to the battery side of the disconnect, so the batteries will charge regardless.

You can check this for yourself with a multimeter. Measure the voltage at the batteries with the batteries turned 'on' and with shore power connected. Voltage should be over 13.2v if charger is working. Turn batteries 'off' and check voltage again. If it starts dropping, then you know that you're not charging with switch in 'off' position.

Our charger is connected to the battery side of the disconnect for a specific reason. We've got an automatic battery disconnect in the system which will disconnect if the battery voltage drops below a preset state of charge. This is to protect batteries from damage if they drop too low.

If the automatic disconnect should trigger, we've got to have a way to get power to the batteries to recharge them, which means the charger has to be on the battery side of the disconnect.

There are many variable to these systems, even within the same brand. A wiring diagram and multimeter will be a good friend to you in these projects.

[Soppy]

Originally Posted by FIRE UP

"....they will not charge...."
Wellllllllll, not exactly. It all depends on how the system was built and, whether or not it's a diesel coach or a gas and, what kind equipment is installed. For instance, our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP, DOES charge the house (and chassis) batteries with the House battery switch in the OFF position. Now, again, it's a diesel unit. But, I cannot speak for gas coaches as, it's been over 8 years since we've had one and, I cannot remember if it even had a house battery cut-off switch.
Scott

My 93 Allegro also charges the batteries with the disconnect in the off position. None of the DC loads will work.
The only sure way is to measure the battery voltage with the disconnect off and shore power connected.

[Spdracr39]

What is your reason for wanting to turn it off? If there is no reason just leave it on.