Battery Disconnect Confusion

[DesertHiker]

Okay, so I went out on Monday to take off on my first trip in my (new to me) 2018 Leprechaun, and the engine battery was dead. Had to call for a jump start. So I learned if my coach is just sitting in the driveway, I should turn the battery disconnect to OFF. (Kinda backwards .. turning a disconnect to off?)

But what confuses me is what happens if I camp without hookups for 7 or 10 or 14 days, which I often do?! How do I keep the engine battery charged so I am not calling for emergency road service in the middle of the back-country?

No, I don't have a "battery boost" for the engine battery.

Thank you!!!!

[DesertHiker]

Thanks, everyone! I learned a lot! I just returned from a consult with my RV mechanic. It is true, I really do not have a battery booster. He is going to install a knife blade disconnect ... thinks that will solve the problem. In the meantime, I am going to put the chassis battery on a trickle charger. Five of my six previous RVs were trailers, and when I was disconnected from the vehicle, I was disconnected! So I am learning.

[DouglasC]

Captain_Happy wrote:
I use to own a Winnebago Vista that did the same thing your dealing with. Went through the whole rig looking for something that was causing a current draw Never did find one. so I just installed a knife blade type disconnect on the chassis battery terminal. That solved my problem

The same thing happened to my Jayco Greyhawk - - chassis/engine battery kept running down when stored - - long ago solved the problem with a knife switch on the battery.

Many motorhomes are wired so that when the coach is plugged into shore power, both the coach and chassis/engine battery are being charged. But that is not always the case. I have been RVing for 34 years and have owned 7 motorhomes. Only one was wired so that the converter did not charge the chassis/engine battery when plugged into shore power. I solved the problem on that motorhome by installing a small trickle charger directly connected to the engine battery. When I was plugged into shore power I ran an extension cord from the 20A plug on the pedestal to the charger. We were full-timing then so the problem only occurred when we camped for more than 4 days in one location & were most always plugged into shore power each night. The knife switch is a better long term solution if the rig spends anytime in storage.

[Captain_Happy]

I use to own a Winnebago Vista that did the same thing your dealing with. Went through the whole rig looking for something that was causing a current draw Never did find one. so I just installed a knife blade type disconnect on the chassis battery terminal. That solved my problem

[Grit_dog]

Desert biker, I’d do a little more investigating and figure out your electrical system(s).
What you said doesn’t sound right.

[bobndot]

DesertHiker wrote:
Okay, so I went out on Monday to take off on my first trip in my (new to me) 2018 Leprechaun, and the engine battery was dead. Had to call for a jump start. So I learned if my coach is just sitting in the driveway, I should turn the battery disconnect to OFF. (Kinda backwards .. turning a disconnect to off?)

But what confuses me is what happens if I camp without hookups for 7 or 10 or 14 days, which I often do?! How do I keep the engine battery charged so I am not calling for emergency road service in the middle of the back-country?

No, I don't have a "battery boost" for the engine battery.

Thank you!!!!

1. Get a set of HD jumper cables that reach your truck battery from the house bank , if you don't have an emergency jumper switch.

2. As said the rv shut off switch in the 'off' position controls the rv house bank not the chassis battery.
You might need to turn it 'on' when plugged into shore power in order for the modern day convertor to charge both banks, chassis and coach, that's how my 2018 FR is rigged using a 'BIM' , battery isolation manager, that monitors voltage of both banks and flip flops between the two to charge them, usually for 15 mns every 35 mns.
If the 'emergency shut off switch' is off only the chassis will charge while driving. Turn it on to charge both banks while driving.

3. I would load-test the chassis battery to see if its good or not.

When batteries discharge and sit for periods of time they tend to fizz out and lose their blood pressure.
If it is good and its discharging, put an amp meter on the chassis battery to see if you have a draw while its parked. If you have a draw, then start pulling fuses individually on the chassis to isolate the area that's causing the draw.

[IAMICHABOD]

DesertHiker wrote:


No, I don't have a "battery boost" for the engine battery.

Thank you!!!!

Are you sure? I have not seen a class C that didn't have one. They are designed for the situation that you described.This is how it works. I should be located to the left of the steering wheel on the dashboard
Looks something like this.

[time2roll]

Are you plugged in during storage?

The disconnect is probably just the house battery. Yes it is best to move the switch to off or storage when not in use and not plugged in.

Chassis battery to start the main engine remains connected and will run down same as any car. Although RV tend to have additional accessories that will run it down a bit faster.

If you are plugged in a great solution is the Trik-L-Start brand combiner that will connect the float charge from the house battery to the chassis battery and keep everything in good shape.

[MDKMDK]

DesertHiker wrote:
Okay, so I went out on Monday to take off on my first trip in my (new to me) 2018 Leprechaun, and the engine battery was dead. Had to call for a jump start. So I learned if my coach is just sitting in the driveway, I should turn the battery disconnect to OFF. (Kinda backwards .. turning a disconnect to off?)

But what confuses me is what happens if I camp without hookups for 7 or 10 or 14 days, which I often do?! How do I keep the engine battery charged so I am not calling for emergency road service in the middle of the back-country?

No, I don't have a "battery boost" for the engine battery.

Thank you!!!!

The battery disconnect switch usually has nothing to do with the chassis battery. It's strictly to disconnect your coach battery or batteries for idle times to keep them from draining.
If you want to keep the engine battery from draining, too, you could install a blade disconnect at the negative - terminal under the hood, or a Triklstart battery maintainer, to charge the chassis battery via shore power or generator, when you're parked with hookups or running the generator. It steals some current from the coach batteries. Or you could use a regular battery charger/maintainer under the hood to keep the chassis battery charged when you're not using the RV.

[enblethen]

See page 39 Generic owner's manual
You should have two battery systems. Coach which operates 12 volt items such as lights, water pump, refer (12 volt control, and furnace)
Another battery system operates the chassis.
The coach system is charged by converter while plugged into shore power or when the main chassis engine is running.
The chassis battery is in most cases charged by chassis engine. Parasitic loads can drain this battery. It needs a trickle charger to keep it up.
Many MHs are equipped with an "AUX" or "Battery Boost" start button to tie battery systems together so if chassis battery is dead you can jump start it with this switch.

[lovetotow]

Not sure but could there be a second battery that runs the camper