I am trying to track down and eliminate known phantom loads because we dry camp almost exclusively. We have a 1998 U-320.
What are some of the common phantom loads on these units?
One on our unit is the newer stereo head unit the previous owner installed. It is tied to the coach batteries but goes into "Stand-by" mode rather than a full off. I need to install a physical toggle switch to turn it off.
Thank you for your help.
Chris
Are you only referring to DC loads? If you have an inverter and televisions, satellite, or any other A/C appliance, they all draw even when turned off. Examples micro-wave, coffee maker, vcr.
Absorption refrigerator
Propane detector
CO detector
Propane solenoid
Engine and transmission ECU/ECM
Radio memory
Leveling system: brain and pump
I am sure I am leaving out something.
Best answer: put an ammeter on each battery cable and start pulling fuses.
Thank you.
Yes, DC phantom loads. Our last coach had a few surprises that we didn't know about at first - like a solenoid on the main LP tank instead of a manual shutoff valve. That solenoid drew 1 amp per hour, every hour, while dry camping.
AC loads will only be a draw when the inverter is turned on. Normally we keep the inverter turned off.
Pulling DC fuses - are these located under the front panel to the right of the stairs as you walk in?
Leveling system: didn't think about that one, but it's needed.
Fridge: Yup, LP fridge but it still has a draw. This two door fridge is huge.
Thanks,
Chris
As Brett said, unless you put disconnects on both battery banks, you will have parasitic loads.
I tracked all of mine down I could, and still have about 30 watts on house batteries. ecm memory on start batteries is about 10 watts.
I cut the wire on the propane solenoid as it was a good load.
Jim,
Thanks for the info about seeing 30 watts. 2.5 amps... Does any of that come from your solar charge controller?
Chris
The parasitic load is very small, even with the propane solenoid running all the time. Just as an experiment watch your voltmeter drop when you turn on even a few interior lights. Even turning on a few LED interior lights will drop the coach battery a tenth of a volt in my coach. If I leave everything turned off I can be out hiking or riding my motorcycle all day long and come back to the exact same voltage I had when I left, even with the propane solenoid on all the time. I used my inverter a lot for the past couple of weeks to run my ice machine and it's murder on the coach battery. I had to run the genset after the inverter was on for only about three hours to avoid battery damage. I had to wake up in the middle of the night at least once or twice to start the genset. It was good in that it helped me keep my electric usage in perspective. Previously my largest electric consumer was my laptop computer running from a 12 volt DC power supply. I'm glad I have my propane refrigerator working again. :)
No, charge controller only charges batteries if sun, shuts off completely with no sun. Basicly what Brett mentioned with the propane shut off coil the biggest.
I disconnected inverter, as it draws current even at idle with no load.
These coaches are HOGS when it comes to parasite loads! One of the projects in my future is tracking them down. The LP valve on my last Sprinter B would draw ~ 20 AH over a 24hr period, that's not small, but, if you use propane, how do you "cut the wire"? All I've seen are NC valves.
Actually, you unscrew, or unbolt the top of the solenoid valve, remove the internals and put back together. I cut the wires to the coil and taped off, and reinstalled the coil on the valve
I went a couple of years both with and without the LP gas solenoid and I can't see any difference in battery life. I have only one 8D battery for the coach and it easily lasts more than 24 hours between generator runs. The only variable is how much I use my laptop with the 12 volt DC power supply. The cell phone I have won't charge any other way due to some weirdness. Once that phone dies and I replace it I won't have to charge my phone through my laptop anymore and I may go two days between generator runs... Put a voltmeter on your coach battery and you'll see what I mean. The voltage will stay the same all day long even with the LP gas solenoid running.
Idle mode draw no load on our old freedom 25 is .12 amps of 12 volt.
Most inverters, turned off (i.e. not providing AC power) are still drawing 12 volt power unless you disconnect 12 volt supply. I installed a manual heavy duty battery disconnect switch on mine. Older inverters draw more 12 volt watts than newer inverters (when turned off). Because my new (6 years old) inverter draws very little power compared to my old inverter (20 years old), I seldom use the 12 volt disconnect any more.
The factory installed burglar alarm in my 1996 U320 was using watts even though I did not have the key fobs so could not use it. I disconnected the power to it (as shown in the electrical diagram), but have not removed it because I cannot find it, although I did find the antenna.
I use the switch on the dash which was factory installed for the Audit System (replaced with See-Level) to provide power to the rear view monitor, the AM/FM/CD, and to the CB radio. I do have to reset the FM radio station presets every time I turn it on.
I reduced the mystery loads in my Foretravel from 6.5 amps to 0.6 amps.
I also installed a switch for the 120VAC going to the entertainment area over the driver's head, and one for the bedroom TV. This reduces the load on the inverter for those times when I need inverter power but not for TV (most of the time).
I found one in the front tv compartment..
It's the solinoid switch that keeps the tv off while driving... attached to ignition lead hot..
Who would think the water pump on.. not running would take 1.8v
Brett... amps, sorry
Sice I disconnected everything to put a big tv there.. and drawers in place of the tv.. figured I'd be ok disconnecting it.