Battery Drain

[Dennis Crawford]

Folks,

I found the source of my battery drain (or least part of it).  I clamped my amp meter onto the cable from the battery to the distribution continuous duty solenoid.  I was showing 1.9 - 2.0 amps.  I started removing wires from the "hot distribution strip."  The fourth wire is the radio.  Guess what?  When I disconnected the radio, the amps dropped.  When I hooked it up again, the radio came on and there was 2.5 amp draw.  This 2005 Monterey has a Ford radio and Sirius satellite.  There is a heck of a draw.

Dennis

[Joel Ashley]

That is quite a bit, esp. if the radio is normally turned off, and only its clock is parasitizing current.  Perhaps there is an unobvious short or unknown auxilliary draw connected to the radio circuit?

Joel

[Dennis Crawford]

Joel,

The radio is off.  When on, the draw went up to 2.5 amps.  The only thing I can think of is that the Sirius receiver is a seperate unit on the driver's side under the dash.  I am not sure if that is receiving constantly or not.   I think the radio is from a Ford company called Vistronix.

Dennis

[Gil_Johnson]

I bet it's the sat receiver.

[Edward Buker]

Another possibility.....I think the radio manufacturers anticipate that the car will kill the power to the radio with the ignition switch being in the off position. The radio manufacturer will not spend money on circuits or internal relays to eliminate the 2 amps of current draw given it is a non issue when the car is running and normally not being drawn with the ignition is off. There is a secondary power lead to the clock ond power on circuit that usually remains powered all the time that should draw very little current. If the coach is wired such that radio comes on with the ignition switch off, then the idle current of the radio is being drawn all the time and not regulated by the ignition switch. If that is the case you could add a manual switch to that line and turn it off when the coach is not plugged in. If the radio turns off with the ignition then it could be the sat radio receiver or perhaps the camera. Those may just be wired to stay on all the time and possiby could be changed.

Later Ed

[Keith Oliver]

In my car, the radio goes off when the ignition goes off, but when you turn the car on again, the clock reads the current time.  If you disconnect the battery, for any reason, the radio senses this and requires a security code input before it will work, and the clock needs to be reset.  The Beaver is the same, except for the security code requirement.  This demonstrates circuitry that needs power on,  to stay in operating mode.  How much? Probably not much, but when you add this to the ECM requirement to keep its memory alive, unless there is something putting a little amperage back into the batteries, they are going to be exhausted sooner or later.

[Gil_Johnson]

I just pulled up Sirius' receiver and it's draw is 1A.  This may be newer and more efficient than the one you have.  Find it and disconnect it or pull it's fuse and see what you get.  The "keep alive" for the clock and station memory should be next to nothing.  I'm guessing 1/10A.

I just received the wiring diagrams for my 2008 Contessa.  With the two main DC master switches off, the only thing that should be receiving power is my inverter/charger.  So I need to see if it's my power gremlin.

[Keith Oliver]

Gil
You will have a separate shutoff for the inverter.  This should always be off, unless you are using an AC appliance and need to turn it on while that item is in use.  At rest, ie with no draw, the inverter will draw about 5 amps and deplete your batteries overnight.

[Gil_Johnson]

Keith,

I would have thought the same.  I've traced the wires and confirmed the wiring with Monaco's wiring diagram.  The main cutoff switch for the house battery bank does not interupt power to the inverter/charger.  It looks like I'll be adding a cutoff switch.

[Edward Buker]

Gil,

It may be that the inverter charger requires a constant battery connection so that it always sees a battery bank when it goes into charger mode. Not sure if they use the load of the bank to absorb the peaks of the waveform. Seems like they would build in open circuit protection on the DC charger side but it is going to look like a dead battery at 0V when sensing and yet draw no current. Not sure how it handles that...just would not want to damage that unit. Probably a call to the manufacturer is in order unless the installation manual covers this.....

Later Ed

[Gil_Johnson]

The installation instructions allow for a switch.