Phantom Electrical Loads

[F431505Kunkel]

Recent RV purchase of a 99 Safari Panther. Going thru RV tunring off all electrical loads I still have a .75 amp DC draw off house batteries. Could it be the monitor for power cord or generator. The electrical AC will shut down if power cord voltage gets too low. Dennis

[wolfe10]

Dennis,

Welcome to the FMCA Forum.

A good place to start is to have someone monitoring the ammeter while you pull the individual 12 VDC fuses one at a time.

But, a more appropriate question may be what means to you have to keep them charged where you store:

120 VAC-- even 15 amp?

Solar?

[rossboyer]

Also, I think that the transmission has a constant load to maintain it's computer. Depending on your chassis, the fuse for the transmission may be mounted in a separate fuse holder. I think you have a Magnum chassis. I had a 1999 Renegade with a Magnum chassis, but I have not had it since 2008 and do not remember where that fuse is located. Possibly it is under the dash below the radio. Wish I could help you more.

[Lenp]

I suspect your 0.75 amp static load is normal. You have a high end coach that has many "features" that require constant current. My Winnebago draws close to the same. I agree it would be nice to determine exactly where each milliamp is going, I doubt you will be able to remove any of the draw.

Potential items that may/will draw a little power:

Any 12 volt powered radio (even if it is turned OFF)

Propane detector

Monitor panel

Any other "smart" options the coach may have

Great reason to have a solar panel on the roof!

Lenp

[tbutler]

When you turn on the water does the water pump run? if so it has circuitry that is monitoring the water pressure. Is there a charge going through the inverter/charger that is charging the engine batteries and/or the house batteries? The CO2 sensor, smoke alarms, leveling system, any of a host of other systems might be drawing a small charge on the system to keep monitoring the condition of systems in the coach. It is hard to find all these ghost charges in a modern system. As Brett says, pull the DC switches one at a time to eventually find all the ghost loads. Keep in mind that even with a zero load, the batteries will eventually lose their charge. The answer is a solar panel or other small feeder AC charge to the coach while in storage. I recommend the latter if the solar panel isn't easy to arrange.

[F431505Kunkel]

I have pulled the dc fuses one at time. When I plug the RV in I hear a thunk. I am not worried about the thunk. But I suspect that the smart part of the transfer switch is using a good hunk of my phantom electric. I have observed that it will shut down if the voltage on the cord goes I too low. Normally I would look to disable this system when boondocking ___but___ I can't if the generator is also using this system. What do you think? Dennis

[huffypuff]

Sounds like you have a voltage and surge protector that monitor shore power. The thunk is when it allows the power if there is no faults. It don't use any power when not on shore power.

[Lenp]

Your transfer switch should NOT be drawing any DC power - it should only draw AC power when it is available. I agree with Huffy on the "thunk" sound coming from shore power monitor.

Why are you concerned about such a small static drain of 0.75 amps? Assuming you have at least two batteries (probably more) with at least 200 amp hours of capacity you can go at least a week before getting too low on battery charge. If your storing the coach, disconnect the batteries.

If you were to check the parasitic drain on your car battery you will find somewhere around 50 milliamps being drawn. Consider the size and complexity of the 12 volt system on your coach, a 15 fold increase is not that much more.

Does your coach have a BIRD (bi-directional isolator Delay)http://www.intellitec.com/assets/pdf/1453-intellitec-pdf-template-53-01000-000.pdf? If so, it could be directing some of your house battery drain to the chassis battery.

Lenp

[smarksel]

I also have a Safari (2001) Ivory X. When in dry storage, my batteries went down to 11.6V after a few weeks. I have four 6V AGM batteries. I notice that when the main 12V switch is on and nothing is running, I'm drawing 3 - 4 amps from the 12V system. Does this seem high. Sometimes, it will go to 0 amps for a few minutes, then back up to 3 - 4 amps. Any ideas?

Thanks

Steve S

[hermanmullins]

Steve, years ago when we had electric clocks in cars, they would draw from the battery to wind the clock. Now with digital clocks, radio menory, refrigerators draws and so on it is a wonder any battery stays charged. With inverter charging for house batteries one also needs a smart trickle charger for the chassis batteries. If shore power is not available then one should run the generator at least once a week to ten days for a couple of hours under at least a 50% load or disconnect the batteries.

Herman

[smarksel]

Thanks Herman

Steve S

[dickandlois]

Regarding Phantom Loads:

One needs to look at items that are remotely controlled or have a soft-switch to turn them on and off. Most of these items are powered from shore power, but there are exceptions.

The refrigerator has a soft switch to turn it on and off, therefor it needs power all the time and depending on the number of - what I consider convenience items require power all the time.

These loads are minimal but additive and one can have a 3 to 6 plus current draw. A number of coaches have relays that latch on but still require a holding current.

The disconnect switches will remove a number of them, but the ECM, TCM and other control or logic systems require power(Think of the vehicle radio clock) (Some times one needs to reset the theft code) to retain information on engine and transmission information stored but not saved in a non volatile integrated device.

Turn off the power and these items need to start over to rebuild the needed running parameters.

So, if your coach converter /charger is not able to charge the coach batteries and chassis batteries at the same time one needs to consider adding a trickle charger of some sort to keep them in good condition.

At times we need to power down our smart phones and computers to update the systems, but they are always drawing power. One of those soft switches again.

Rich.

NOTE: Forgot one that many over look and I did in this post. The LP safety circuit and the supply solenoid draws a fair amount of current and unless you turn it off manually it is always on and needs to be turned off when refilling the LP tanks !!!