Trying to make sense of Aladdin voltages

[amphi_sc]

 After 10 years with this coach I'm trying to understand what to believe in the various 12V voltage displays vs a meter ... or if I should wire in another remote display directly at the house batteries and maybe a shunt.

So ... We are unplugged, have a the factory provided Heliotrope 30D, about 600 Watts on the roof, 4 pm mostly clear sky with a few thin clouds about 4-5000 ft, been driving about 7 hours after boondocking yesterday, and big boy has likely been engaging "sometimes" and has clicked off now.

Here's what I see at this exact moment:

Handheld voltmeter on either set of 2 per parallel set of 4 12V Lifeline 4D batteries (two different compartments) 12.6v and 12.54v

Set of 4 Lifeline 12v Chassis batteries 12.6v

Magnum remote says inverting 12.1V at 25 amps

Aladdin solar display 16.1v 14.4a charge and Aladdin house bats display 13.1v 29a discharge.  (Notice 12.1 vs 13.1 vs at the bats 12.6)

(Aladdin may  typically show anywhere from 11a to 30a discharge depending on of residential fridge and or bay Engle 110v freezer is running at the moment ...)

If I remove & measure at the 30a solar fuse at the house bats I get battery voltage on one side (makes sense) but 2.4 volts on the other side of the fuse holder. At the Heliotrope itself house is indicating 12.6 and Chassis 12.8 across the terminals. The "bulk" led is lit. With fuse at the house bats removed I get the 2.4 volts and bulk led goes off.  So I guess the solar controller shuts down if no battery voltage detected?

Driving during the day the Aladdin house showed 13.5-13.6 jumping occasionally to 14.5 for a few minutes then back down. Sometimes showing 0 amps, sometimes 3-4 a discharge, and other times maybe 7-25 amps charge. (In the early AM driving I was getting 50-70 charge from the alternator I believe recovering from overnight).  Chassis batteries stayed fairly constant at 13.5 to 13.6 even when the house indicated 14.5.  During the drive Solar ranged up to 18.4 volts and 25 amps.

So how is the alternator - big boy - solar - inverter all playing together?  Indicated voltages are all over place but chassis seems what I would expect.  Is the big boy engaging sometimes if the house & freezer draw the battery down when the solar is providing less current than demanded?  If the demand is low is the solar going into equalization mode and big boy disengaging. My handheld volt meter can't handle reading more than 10a so I don't want to plug that inline with the 30a fuse to get an amperage reading. (Maybe at dusk as current drops). I also noticed what looks like a 18 ga pair of wires hooked as one wire on one of the "temp comp probe" terminals and the other "minus ext voltage sense" Strange??

Anyway, I'll ponder all this for a while...

 

Oh, one more thing that led to my pondering all this.  Last night when I shut down to boondock the Aladdin showed 100 amp discharge which was very very very unusual so I started flipping breakers trying to find the uncommon heavy load.  Started think fridge died as freezer showed 14° and Fridge side 52° and when I flipped the residential fridge breaker the heavy load went away.  But flipped back on and no heavy load and within 10 minutes freezer showed -1 and fridge at 36°.  Did I just randomly catch it at some defrost cycle drawing a lot of current?  It is working normally today.

[96 EVO]

Fridge should never reach 52F even defrosting!

Residential fridge?

[amphi_sc]

1 hour ago, 96 EVO said:

Fridge should never reach 52F even defrosting!

Residential fridge?

As stated in original post: residential fridge.  And then temps were back to normal within 10 minutes.  So wondering if temp sensors were measuring temp at the evaporator coils as maybe??? it was on an automatic defrost cycle and then when the circulation fans kicked back in the sensors measured true temp??  So can I trust the freezer display of -1 or +14 just minutes apart? However still begs the question why inverter showed 100 DC amps until fridge breaker cycled and fridge seems okay today.

But back to the observation that battery volts between Aladdin display - inverter display - and hand held meter at the bats all read significantly different.  Today I also measured voltages at the lugs in the front run box and got another set differing readings.

Edited February 12 by amphi_sc

[Tom Cherry]

10 hours ago, amphi_sc said:

As stated in original post: residential fridge.  And then temps were back to normal within 10 minutes.  So wondering if temp sensors were measuring temp at the evaporator coils as maybe??? it was on an automatic defrost cycle and then when the circulation fans kicked back in the sensors measured true temp??  So can I trust the freezer display of -1 or +14 just minutes apart? However still begs the question why inverter showed 100 DC amps until fridge breaker cycled and fridge seems okay today.

But back to the observation that battery volts between Aladdin display - inverter display - and hand held meter at the bats all read significantly different.  Today I also measured voltages at the lugs in the front run box and got another set differing readings.

First….download the Battery 101 file. There is a discussion there.  The Magnum remote is the LEAST accurate of your “meters”. The Magnum Specs say “+/- 10%”…IIRC. But having done discharge drills over the years to exercise my batteries, I can tell you that your Magnum is actually reading “about like most”. When I discharge, I record the 15 minute voltages….hand held high end VOM on the house bank as well as the Magnum remote. NOW, from what we were taught in my Engineering courses and my Stat courses (Dr. Deming was a lecturer), my “DESIGN OF EXPERIMENTS” is correct. When I discharge, I have a FIXED load (450 watts).

Therefore, the correlation of my Hand Held and Magnum is close. I know that there will be about 0.10 - 0.20 variation….as in the Magnum is reading lower. Magnum says…it is the “distance”.  My standard gripe with Magnum….how can you have that much error and then correctly set an AGS. I have also ran the correlation AFTER the discharge cycle is complete and then wait until the house bank has recovered or “popped back”. SAME variation. I KNOW to set the AGS lower to actually get to 50%….rather than constantly “short cycling” the AGS.

My recommendation….

Do a correlation study. Drain down the batteries with a fixed load.  450 watts is recommended.  A Halogen work light is best. Turn OFF all the entertainment devices….as in unplug or lut on a power strip and turn off. Kill the residential refer. Unplug all cell chargers.  Then drain and record.  Maybe 10 - 15 minute intervals.

Record using a good VOM, Magnum and Aladdin ….compare them. The VOM is the benchmark. Once you know the correlation amount…write it down on a sticky note and post one on the Aladdin and the Magnum…

NEXT….disconnect ONE of the control wires to the Big Boy. Start the engine….read all three again…but include the Instrument panel voltage.  Since the BIRD System is disconnected….you are ONLY charging ONE BANK.  IF you could find a high wattage load, like a small 500 watt inverter with the work light on it, then you could load up the chassis….that would add about 40 amps….

Bottom line…your VOM is the most accurate.  The Aladdin is getting the DC from each bank… I think one set of readings at idle would be sufficient to correlate.

PAST THAT….if you have fluctuations, you need to reduce or eliminate loads. Look at the specs for your RES REFER.  The FLA is when the icemaker mold is heating and you are in defrost mode and the “internal” heaters and compressor is on,  THEN, unless you have a clamp on ammeter….the only way to measure the RES REFER is to keep ALL the DC devices OFF.  Kill the AC. Watch the Magnum and see what the NORMAL amp draw is .  Multiply DC volts times amps. Divide that by 120. That is the “guestimate” of the AC amps.  Compare that with the FLA.  That delta tells you how much “variation” you will get with the Res Refer at max draw…

Hope this helps….I would NOT sweat this until I did the studies….then, you KNOW what is going on….and you ARE going to have variation.  You can’t “fix” or adjust the Magnum. Doubt you can calibrate the Aladdin….so you stick with facts and not try to rationalize what you are reading as it is a “relative” measurement,

[jacwjames]

I asked a similar question a couple years ago about my Xantrex inverter display.  Never seemed to correlate or make sense, especially during/after charging batteries with generator.   Voltage was all over the place even though I have installed a Bluesea MLacr that ties both banks together. 

That drove me to install a BMV712 battery monitor, https://www.victronenergy.com/display-and-panels/bmv-712-smart

Now I know what both batteries are and can check it via bluetooth, works great to look at and compare battery bank voltage.  Being able to see what amp draw and remaining capacity on house batteries is also a good tool.  

[Frank Bergamo]

16 hours ago, amphi_sc said:

Oh, one more thing that led to my pondering all this.  Last night when I shut down to boondock the Aladdin showed 100 amp discharge which was very very very unusual so I started flipping breakers trying to find the uncommon heavy load.  Started think fridge died as freezer showed 14° and Fridge side 52° and when I flipped the residential fridge breaker the heavy load went away.  But flipped back on and no heavy load and within 10 minutes freezer showed -1 and fridge at 36°.  Did I just randomly catch it at some defrost cycle drawing a lot of current?  It is working normally today.

This has been happening to me also. Recently pondering equalizing house batteries due to perceived underperforming house battery capacity.  With inverter on, what I did was disconnect most of the AC load, including residential refer, and let sit for 2 days and then measured battery voltage. Readings were 12.5-12.6 range implying to me batteries were sufficient. What puzzles me is why Aladdin shows 100 amp discharge occasionally, until I shut off residential refer breaker, then back to normal. I considered the refer has a defrost heater that may be malfunctioning and drawing excessive amps when going into defrost mode. In reading Al’s post, I see he also has a 2007 Beaver as I do, and am now wondering if this may be a problem common to our similar year coach. Getting ready to leave on a trip tomorrow and hoping to maybe figure out what is going on. Will keep an eye on things and will report back with any findings.

[amphi_sc]

Hi Frank, Interesting you've seen a mysterious 100 amp draw too that went away when fridge breaker is manually flipped!  My Fridge is the factory installed 22 cu ft Jen-Air.  When I noticed my high amp draw it was after driving for the day and getting set up to boondock the night.  I always turn off the ice maker the night before travel day as I wanted the tray to be securely frozen and didn't want it dumping ice and refilling with water while driving.  So my 100 amp draw was with ice maker arm up - shutting off the cycle from the previous night. But still the strange draw seemed fridge related.

[Frank Bergamo]

Very interesting, same refer, same symptoms. My ice maker is always off, arm up. Will have to dig into this specific refer a bit more. Thanks for the info!

[Frank McElroy]

On my Jen-air, when dry camping, I select the vacation mode and then close the door.  This will block the defrost heaters from turning on.  The only catch is that the next time the door is opened, the vacation mode ends and will allow a defrost cycle unless you again press the vacation mode before closing the door.

[Frank Bergamo]

Wow, thanks Frank. Never knew that was there! My eyes are not what they used to be. Will give it a try and see what happens!

[Frank McElroy]

I often dry camp at truck stops overnight and found this to be a great feature on the Jen-air side by side residential refrigerators.  Just be sure to turn it back on if you open either door to get your midnight ice cream or adult cold beverage.

[96 EVO]

Ha!

My wife doesn't need any more 'procedures' to follow !

And, if I tried adding another, it may be detrimental to MY health!

Edited February 14 by 96 EVO

[amphi_sc]

Re: Jen-Air vacation mode.  Learning something new.  I pressed the button on, the led lit up.  I opened and closed both fridge and freezer doors several times and the vacation led stayed lit !  I pressed it off.  Then I pressed it back on again just before retiring for the night and will see of it stays lit after tomorrow morning's breakfast routine.

[Frank McElroy]

I believe there is a certain time window that after you press vacation mode it will stay on even if the door is reopened.  After that window, the next time the door is opened it will go back to normal operation.  I don't recall now what that time window is.  I just got in the habit of being sure it's still on if I need to open the door at night.

[amphi_sc]

My dear wife made it to the fridge this morning just before me so when I opened the door maybe 5 minutes later the vacation mode light was off.  That would have been about 8 hours after I turned it on.  The ice maker dumped since turning on vacation mode last night, but as I was still in the bathroom when DW opened the door this am I don't know for sure if it just dumped or dumped much earlier while we were sleeping.  However it's now been 25 minutes since she opened the door and the ice tray feels frozen (I just thought about a skinny finger touch to the ice surface) and not as fresh liquid water ... implying vacation mode didn't also disable ice making.  But I think I need another test run or two before decisively concluding.

[Frank McElroy]

3 hours ago, amphi_sc said:

My dear wife made it to the fridge this morning just before me so when I opened the door maybe 5 minutes later the vacation mode light was off.  That would have been about 8 hours after I turned it on.  The ice maker dumped since turning on vacation mode last night, but as I was still in the bathroom when DW opened the door this am I don't know for sure if it just dumped or dumped much earlier while we were sleeping.  However it's now been 25 minutes since she opened the door and the ice tray feels frozen (I just thought about a skinny finger touch to the ice surface) and not as fresh liquid water ... implying vacation mode didn't also disable ice making.  But I think I need another test run or two before decisively concluding.

I don't believe vacation mode disables ice making.  It just stops the defrost cycle.

[Tom Cherry]

1 hour ago, Frank McElroy said:

I don't believe vacation mode disables ice making.  It just stops the defrost cycle.

If there is a separate ICEMAKER ON/OFF light or switch, I would think along the same lines as Frank. The Samsungs have TWO separate switches.  ECONOMY and ICE MAKER. BUT, the ECONOMY does NOT flip back and forth when you open the door.  It is a PURE MODE switch and you set it.  BUT, when you power down...then the reboot or restart goes back to NORMAL operation...NORMAL Cooling and NORMAL Ice making

If you don't have a manual, pull the PN and google the manual.

 

[amphi_sc]

As stated earlier, it's a Jen-Air not a Samsung.  Probably will just continue to raise the ice maker arm as I've always done.  The hint on vacation mode to avoid the 100 DC amp draw and the unnerving fridge/freezer temp displays is handy knowledge.