Engine battery

[Davion206]

What would drain the engine battery on our 2017 class c? Went to unlock the doors on our class c mh with the remote and zilch....tried the auto door locks from inside and zilch....put the charger on the engine battery and started the engine to let it run. It has been stationary for a few months now.

[Harvey51]

I recently learned that the vehicle remote control radios use quite a bit of power when the remote's batteries are low. A friend had trouble with her car battery going dead for months. The problem ended when she put a new battery in the remote. The thinking is that the car's radio connecting to the remote sensed a weak signal assumed it was quite a distance away and upped the power level of transmissions to it.

[maillemaker]

FYI, the Harbor Freight battery disconnect switches work well with their rotary knob, but the plastic knob piece has a tendency to slip on the brass part it is molded over. To fix this, I put it in my drill press and cross-drilled through the knob into the brass, and pressed in a pin. Now the knob does not slip.

Steve

[j-d]

Our first Class C did not have a Coach/House Disconnect like we've come to expect. Nor a Chassis/Engine Disconnect that we usually don't expect. In BOTH cases it did not run either battery down when not being used or plugged in.

The one we have now, Does have a Coach/House Disconnect, and the Battery Will run down if not disconnected. But, still, our Chassis/Engine battery does NOT.

On the first coach, I moved Dashboard Radio source from Chassis to Coach so I wouldn't have to have the Key in ACC to listen to the radio. So no Radio or Memory drain on the Chassis.

On this one, it'll play with either the Coach/House battery ON, **OR** the Engine Running. Just an ordinary "car stereo" and no Battery Select Switch ffor Radio like some Winnebago products. No idea how it works, but it does... AND it saves Memory, so I can only figure its Memory is wired around the Disconnect.

EDIT: OH! Be sure any Engine Battery Disconnect you use, is good quality, adequate amps capacity, properly installed. It's your ability to start the coach going on here, and that starter is high amps.

[Harvey51]

Davion, I'm interested in your switch method. Did you put a switch on the smaller cable going to the positive battery terminal? I haven't seen anything in the stores to do it easily.

Ideally the switch would be conveniently located in the cab. Maybe a relay that only uses power when switching.

I disconnect a battery cable on our 2 infrequently used vehicles. I see battery post disconnects that only fit the negative post but there isn't room for it on the 1992 GM van.

The problem is compounded in a cold climate because it takes more energy for a start and charging is less efficient so even vehicles used daily for a short run will gradually run down. Especially if there are several starts in a shopping trip of a few blocks.

[Davion206]

Thanks for all of the response....good to know it's a common problem. DH had already decided to install the battery disconnect.

[maillemaker]

I installed battery disconnect switches on both my engine battery and house battery bank for just this reason. Every time I park the RV I disconnect the batteries. That way they are fine when I go to use the RV.

Steve

[ksg5000]

As others have said - plenty of hidden draws on batteries and dead RV chassis batteries are common. If your rig has access to shore power then consider keeping it plugged in and buying a Trik L Start - that enables chassis battery charging while your plugged in.

[klutchdust]

I plug my coach to ground power at the house. I use a black and decker charger that plugs into 120 circuit then plugs into the charging port on the dash or for you older folks the cigarette lighter hole. Keeps it charged just fine.

[ScottG]

If you leave the fob inside it, that can cause it to drain quickly.

[theoldwizard1]

Not uncommon for modern vehicles for the battery to discharge when not started for over a month.

[Dusty_R]

With all the engine computers with memory the battery will go down in a few days. Twenty plus years ago the batteries would hold for several weeks.

Dusty

[MDKMDK]

Radio, OBD/PCM, most likely culprits.
Courtesy lamp under hood with faulty mercury switch, if there is one there, or else where.
Apparently some power electric steps can draw current from the chassis/engine battery.
Door not closed dome light?
Lots of things can do it over a few months.

[Sloop_Smitten]

Just a guess, the radios memory draws about 50mA and over a few months will deplete the charge on the radio. I added a switch to allow me to turn off the memory when I think I may not be using the M/H for more than 30 days.