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Main Forum => General Discussion => Topic started by: fandj on September 26, 2016, 05:45:06 pm

Title: The Case of The Missing Power
Post by: fandj on September 26, 2016, 05:45:06 pm



We picked our 2552 up in late June and noticed an unexplained power loss and have to date not been able to track it down so hopefully those more familiar with the PC electrical system could explain the loss or help me track it down. 



We typically camp without electrical hookup so knowing our usage is crucial to managing battery charge.  To keep track I installed a Victron power monitor.  This allows for tracking of amperage going into and coming out of the battery, amp hours used, voltage, and state of charge (percent of full charge).  To replenish power used I had Phoenix install two 160 watt solar panels to which I wired to a Morningstar MPPT charge controller.  The solar charging system works very well and when sun is available I am typically back to 100% charge by mid to late morning.  However with the day's getting shorter and lower sun angle I anticipate not being able to fully recharge when camping.



Some items I had Phoenix install that were not standard on the 2016 models were (1) a rotary disconnect switch in lieu of the relay type disconnect switch (2017 models to have the same rotary switch I had installed), (2) A Samlex 2000 watt pure sine wave inverter instead of the Xantrex inverter, and (3) a 60 amp Progressive Dynamics converter in lieu of the Parallax model.



Now for what I know and the mystery.  With all loads off including lights, refrigerator, water pump, furnace, solar charging system, inverter (turned off at remote and local which according to Samlex manual stops all power going to inverter), fans, etc. the Victron shows a loss of 0.70 amps from the battery.  I removed the 3A fuse for the Propane detector and the loss dropped to 0.65 amps.  With the battery disconnect switch turned off the amperage removed from the battery is 0.45 amps.  I guess Phoenix wired the battery disconnect switch only as a partial disconnect which I find troubling.  It appears the only way to truly disconnect the battery is physically disconnect the battery wire from the battery.



Even though the amperage loss seems relatively low the hit to the battery is almost 15 percent of the usable battery charge per day with "everything turned off".  This unexplained loss is significant particularly as solar charging drops off as the days get shorter.



For those of you without solar have you found the batteries run down fairly quickly if the unit is not driven or connected to shore  or generator power?  My calculations suggest a parked PC with everything turned off could deplete the batteries in as little as a couple weeks if not recharged and would be doing damage to the batteries in half this time.



I would appreciate any information anyone could provide as to where the losses might be occurring and any possible solutions.

Title: Re: The Case of The Missing Power
Post by: 2 Frazzled on September 27, 2016, 09:31:08 am
I can't answer the question "what is pulling power?" but I can say that our 2013 2552 has sat for several months at a time with no driving or usage with the battery kill switch off and the batteries are mostly charged when we take her out. They have not drained as you stated yours does. They drop a little, but not much.

One battery drain we keep an eye on is the tank heaters. People reach for the water pump switch in the bathroom (middle of the night, half asleep, etc.) and hit the other switch in the same area, which is the tank heaters. Unless you replace the switch with one with an indicator light, you don't notice the heaters are on. Some people have replaced this switch with a lighted one as mentioned and others have simply inverted the switch and painted the "bottom" of the rocker switch bright red so it catches your eye when you walk in the bathroom and you realize it is in the "on" position. My brain says the kill switch should be turning this off so it may be a moot point.

One thing I would check is the front cabinet where you have a cigarette lighter type 12v outlet as well as the TV and antenna connections. I wonder if those remain "live" when the kill switch is off. Also with your inverter/converter change, do those draw directly from the battery and somehow bypass the switch? If yours is pulling power when ours doesn't, it may be the changes you had done.

Last, did you call Phoenix and ask if there is anything that is "exempted" from the kill switch? I know our steps work when the kill switch is "off" so they either feed off the truck battery or they bypass that switch.
Title: Re: The Case of The Missing Power
Post by: Gail Staton on September 27, 2016, 10:27:36 am
Unfortunately we do have the same problem, fandj and have not been able to determine the cause of our batteries draining.   If we store ours for short periods we charge them with the generator every week or so.   Storing for longer periods we disconnect the  batteries.   Our storage facility is just 2 miles from our home otherwise we would disconnect the batteries every time we return from a trip.    If we dry camped like you, we would have to pursue this further.

Our step runs off the chassis battery. 

If you determine what is causing your draining we'd appreciate knowing your findings.

Gail
Title: Re: The Case of The Missing Power
Post by: fandj on September 27, 2016, 09:04:55 pm
Thanks 2 Frazzled you brought up an item I should have mentioned in my initial post.  I should have included in my list of items that were turned off the antenna amplifier.  I had also discovered in the same cabinet as the antenna amplifier a powered IO box for DVD/TV.   I installed an on/off switch so the IO box could be turned off when not needed.  I found it required another 0.25 amp to operate.  The current draw listed in my initial post were with the antenna and IO box turned off.  You mentioned a 12 volt outlet in the same area. Either I have overlooked it or it was not installed.  Other than the 12 volt outlets provided in the Ford dash Phoenix did not provide any 12 volt outlets in the coach.

You also mentioned another good point which is the tank heater switch which I doubled checked and confirmed it was in the down position which I believe is off .  To check this I viewed the battery current draw on the Victron gauge with the switch in both up and down positions and noted no change to the current.    I was not able to find a dedicated fuse to check but did confirm the fuses for the other electrical items in the rear were good. Now I suspect a problem with the tank heaters.  Are the heaters controlled by a thermostat?

I did mention to Kermit this unexplained current draw early on and he thought it could be the inverter.  I checked the Samlex inverter operating manual which i understand that the switch on the inverter itself turns off all power draw whereas the remote inverter switch does not.  With this information I have always insured the main inverter switch is off.  I have not gone back to Kermit but was hoping others may have run into this unexplained power draw and may have a solution.

Thanks for your comments and I would appreciate any further information on tank heater thermostat, wiring, fusing, etc.
Title: Re: The Case of The Missing Power
Post by: keelhauler on September 28, 2016, 06:41:27 am
In my 2552 the tank heaters use fuse #1 on the converter.

The Macerator, Slide-out and Generator starter get power even with battery disconnect turned off.
So those are some others places to look at. They use circuit breakers not fuses.
Title: Re: The Case of The Missing Power
Post by: 2 Frazzled on September 28, 2016, 07:00:42 am
The 12v outlet is just a round hole next to the red light and button for the antenna/TV thing on the very front wall of the cabinet over the passenger seat. Someone on the forum tipped me to that one. It's possible they don't install that anymore but I don't see logic in that so I suspect it is there, you just didn't know it.

No other ideas on the battery drain.
Title: Re: The Case of The Missing Power
Post by: fandj on September 28, 2016, 07:34:31 am
Keelhauler,  thanks for your reply.  I have used your electrical schematic you posted to help me understand the PC electrical system and found it most helpful.

I have a couple of questions (1). Should the macerator, slide, and generator consume power while setting idle?  (2). I see you have a Trimetric power monitor, what is your current draw with everything turned off with the battery disconnect switch turned on and off?

I have looked through your earlier post and you seem to have a very good understanding of the PC systems.  I am new to the PC world and coming from a simple pull type camper so the learning curve is pretty steep at this point thus any help would be greatly appreciated.
Title: Re: The Case of The Missing Power
Post by: keelhauler on September 28, 2016, 08:08:06 am
I have never looked at the current draw with everything turned off, I will when I'm getting our RV ready to head south for the winter in about a month I'll take a look.

I will tell you that when my RV is stored, I leave the switch on to the truck battery (I changed that switch to a toggle, rather than a momentary switch) as that battery seems to go dead fast. My two arrays are not in the sun for much of the day but all 3 batteries stay fully charged with everything connected and battery disconnect left on. The only thing turned off is the inverter remote switch.

I don't know why the slide, macerator or generator start would pull any power, but the 3 circuit breakers are under the passenger side bed, It would not be hard to lift off those, brown, green & blue wires, one at a time to see if your current draw changes.

I love the Bogart monitor, as I always know the battery charge status.

The one time I did draw my batteries down was when I left the antenna amplifier switch on. I alway look for the little red led light to make sure it is turned off..
Title: Re: The Case of The Missing Power
Post by: donc13 on September 29, 2016, 06:31:06 pm
Keelhauler,  thanks for your reply.  I have used your electrical schematic you posted to help me understand the PC electrical system and found it most helpful.

I have a couple of questions (1). Should the macerator, slide, and generator consume power while setting idle?  (2). I see you have a Trimetric power monitor, what is your current draw with everything turned off with the battery disconnect switch turned on and off?

I have looked through your earlier post and you seem to have a very good understanding of the PC systems.  I am new to the PC world and coming from a simple pull type camper so the learning curve is pretty steep at this point thus any help would be greatly appreciated.

Disconnect the chassis battery.  There is an isolater that should block the chassis battery from drawing down the house batteries but still allow the engine alternator to charge the house batteries.   SOME battery isolators do not stop the flow from the house batteries to the chassis battery 100%.

Thus the parasitic feeds (engine computer, radio, etc.) will slower (very slowly) drain the chassis battery which COULD cause a draw on the house battery.

Title: Re: The Case of The Missing Power
Post by: fandj on November 24, 2016, 03:07:00 pm
I wanted to provide a follow up on my power loss mystery.  I noticed with all electrical items in the coach turned off when I then turned my battery disconnect off I could hear a chirp sound from the propane detector then a second sound of a relay.  It turns out the relay sound was the macerator relay which draws 0.21 amps with everything off.

I recalibrated my Victron ammeter and found for some reason the zero point had shifted from where I had it in a previous camper.  It now shows with the battery switch off the drain from the battery is zero.  With the switch on the drain is about 0.24 amps of which 0.21 amps goes to the macerator relay and about 0.03 amps going to the propane detector.

I feel I have a somewhat better understanding now of how battery power is consumed in the coach.  Why the macerator is energized while in standby mode I still don't understand.  It would seem like when the macerator pump switch is turned on it would energize and close the relay contacts which in turn would provide power to the pump.  If this relay power loss could be eliminated the only other draw is the propane detector.  The draw from the detector is minuscule and is important from a safety perspective.

If other Phoenix models have the same macerator current draw as what I found in mine I can see how the battery could be drawn down to 50% in about a month while in storage if the battery disconnect switch is not turned off or the battery is not physically disconnected.
Title: Re: The Case of The Missing Power
Post by: ron-n-toni on November 25, 2016, 10:07:01 am
Just a shot in the dark. Solar panels will drain a battery at night and require a diode to stop any reverse flow. They are usually in a small watertight box on the back of the panel. Just disconnect panel and check with an olm meter. Should have a reading in  one direction and none  in the other. Had this happen once and nearly drove me nuts.
Title: Re: The Case of The Missing Power
Post by: Ron Dittmer on November 25, 2016, 01:56:32 pm
Our PC is coming up on 10 years old and I experience this.  With everything in the house shut off and the kill-all switch off as well, and the batteries disconnected, when I place the battery lead on the battery terminal, I get a big spark.  If I lift the lead and immediately touch the battery terminal again, I don't get the spark.  To this day 10 years later, I never understood why it happens.  One thing certain, there is a minor power drain when the batteries remain connected to the motor home while in storage.  Since I go in there now and then over the winter, I leave the batteries hooked up, but I occasionally recharge them manually with my Black and Decker charger.  I am not comfortable having the rig plugged into a wall outlet all the time.
Title: Re: The Case of The Missing Power
Post by: fandj on November 25, 2016, 04:18:43 pm
Ron, on my unit there are three cables leaving the battery area.  One goes to the generator starter, the second goes to the HWH leveling system, and the third goes to the rotary battery disconnect switch.  All are fused near the batteries.  It appears the generator and HWH system do not draw current until actuated by their respective control button.  The one going through the battery disconnect switch goes to the propane and macerator relay which are always "on" and combined draw about 0.24 amps of current.  The other 12 volt loads getting power through battery disconnect switch can be switched "off" through their local switches.  By turning the battery switch off it appears to stop all parasitic drain from the battery.

The photo shows the rotary battery disconnect switch and shore power surge protector display.
Title: Re: The Case of The Missing Power
Post by: RheaNL on November 26, 2016, 08:39:36 am
Ron, why don't you like to leave your unit plugged in? Ours is stored outside under a carport and we leave it plugged in to a 30AMP RV plug (not to be confused with a 30 AMP dryer plug).