House batteries drain overnight.

[Tobythepug]

I have a Monaco Knight 40pdq with 4 new 6volt Lifeline AGMs each with 330 ah. Total out put fully charged is 660 amp hrs. Over night dry camping our frig will turn off and low battery will be indicated. Everything else is turned off. Also while under power driving same issue where inverter turns off. Have to recharge with the gen set even while driving. Can the alternator be redirected to keep the house batteries fully charged. Can’t believe the electric only frig can drain the battery pack. Any suggestions appreciated. 

[Gary 05 AMB DST]

What year is your Knight?

Gary 05 AMB DST

[DavidL]

You will have to determine if there is an unusual draw, or if the batteries don't have capacity, or if they aren't being charged.

Let's assume the batteries have capacity since you advise they are new.

Are they connected correctly?

Check that the four 6 volt batteries are putting out 12 volts ie: they are properly wired in parallel.

Put an ampmeter on the circuit to check for draw.  Monitor this on a regular basis to see if something is turning on periodically pulling lots of current (like a refrigerator)

Check with the system connected to land line that you have More than say 13 volts ie: the charging system is working.

How long have you noticed the condition?  What changed at the same time?

 

Let's assume you noticed that the batteries weren't lasting as long as they used to and that's why you replaced them.  And then at that time, now you have to run the genset to charge them which historically you didn't need to do that...well, that points that when the batteries were replace, that something wasn't wired back the way it was / is supposed to be wired.

Edited October 31, 2022 by DavidL

[Tobythepug]

Only solution we came up with was to turn off the fridge overnight and keep the doors shut. Freezer won’t hold at 2% and hits closer to 33. Cooler side stays around 36%. Have also turned off the inverter to save power. Once again this only happens when off grid and boondoging. Should the alternator be charging both house and chassis while driving? The unit is 2012. It does not charge the house setup and we have had to drive with the gen set on. 

2 hours ago, Bigboy said:

I have a Monaco Knight 40pdq with 4 new 6volt Lifeline AGMs each with 330 ah. Total out put fully charged is 660 amp hrs. Over night dry camping our frig will turn off and low battery will be indicated. Everything else is turned off. Also while under power driving same issue where inverter turns off. Have to recharge with the gen set even while driving. Can the alternator be redirected to keep the house batteries fully charged. Can’t believe the electric only frig can drain the battery pack. Any suggestions appreciated. 

The unit is 2012. 

[BradHend]

Low battery is indicated at the fridge or at the  system display? 
Do you have a modified sine wave inverter? 

Reason I ask is it may not be your batteries, but rather your fridge controller doesn’t like the modified sine wave inverter. 

[vito.a]

What model refrigerator do you have and did it come from the factory or was it added later?

Have you turned off the ice maker?  (The reason is most icemakers use electric heat to release the ice cubes.)  

What model year is your Knight?

What is the date code on your "new" house batteries? 

Are you certain your house batteries were fully charged? 

How old are your chassis batteries?

Most Monaco diesel coaches use an Intellitec "Big Boy" isolation relay to join the house and chassis batteries.  When the battery voltage reaches the specified level it closes and both battery banks are charged.   The Knight may have only a subset of this system.   Your owners manual will explain it in detail.  

By comparison we have a Samsung RF18 refrigerator and four Trojan T-105 6-volt batteries.  With the ice maker off it will easily last overnight and that includes lights and some TV time before bed.  

Also, make sure you're not trying to operate the microwave or a coffee maker on battery power.  

Edited October 31, 2022 by vito.a

[96 EVO]

You don't have the year of your Knight in your sig, but it's possible it never left the factory with the ability to charge the house bank from the alternator.

[Rocketman3]

I think one of the best items to help figure out problems like this  is to install a Victron Smartshunt or BMV712. 
 

it is also really nice because it lets you know how full/empty the batteries are. Plus the time until batteries empty is really great!

Do you have a propane/electric fridge that was on electric when camping?
 

 

[TomV48]

5 hours ago, Bigboy said:

Only solution we came up with was to turn off the fridge overnight and keep the doors shut. Freezer won’t hold at 2% and hits closer to 33. Cooler side stays around 36%. Have also turned off the inverter to save power. Once again this only happens when off grid and boondoging. Should the alternator be charging both house and chassis while driving? The unit is 2012. It does not charge the house setup and we have had to drive with the gen set on. 

The unit is 2012. 

Yes.   The alternator SHOULD BE CHARGING THE HOUSE BATTERIES.   Turn off the frig.  With engine off test voltage on truck batteries and house batteries.  Then start engine repeat voltage check.   In my 05 ambassador there is a "BIG BOY" RELAY that adds house to the charging once the engine batteries have a chance to charge up a bit from the fast heavy load of starting.       The control comes from the front elec box under the driver's window.   "IRD" Ignition Relay Delay.   The Big Boy sits on the wall at the back of my battery compartment (right near the rear)

My friend, with an Imperial (couple models above our Ambassador) has a different cross charging system so I know there are variables.  

I put in a DC to DC charger which puts out 40 amps when I go down the road.   When the propane system in the fridge failed, we had to limp on electric while waiting for replacement frig.   A Norcold 1200 pulls 40+ amps through the inverter to run full time on ac so we got a work out.   Your res frig can pull a lot, but if cooling correctly it does not run 100 % duty cycle like the a/c propane dorst.   

 That's just my first level suggestion.  Good luck.

Oh..  And there is this.  We have two good RV friends with res frig.   Both had 6 wet 6v batteries and could seldom get through the night.   They were during the frig off at bed time and on at crack of day.   Still had to run generator 5-6 hours a day.   Now both are sporting six Battle Borns and 800 watts of solar.  Problem pretty much solved.

[Tom Cherry]

Lots of comments.  Also some research in your manual so these are facts and not guesses.....your KNIGHT ain't the SAME KNIGHT as the older ones are.  It is MORE sophisticated in that it DOES have BIRD charging.....and probably a Pure Sine Wave Inverter..... From the TOP.

You need to go into the SETUP of the Magnum and make sure that the battery type is AGM.  If you are not proficient with that, read the manual or call Magnum they will help you and get it resolved. If it was not changed when you put in the AGM's it is set to FLOODED.  The Search Watts should be OFF....which is the first setting.

I can't tell from the Owner's Manual but I SUPSECT that you DO have a Full Sine Wave model.  Look on the Inverter.  ME is a Square or older style.  MS is the newer one.  If you have the Residential (OEM) Option, you will have a MS2812.....or that is my belief.  Post the Model number as folks maybe guessing.  The 2012 Knight had a lot more features than the older ones did.

On page 188 of your Manual, that states that you DO have BiDirectional Charging.  In other words, the Magnum Inverter/Charger will charge BOTH.  Also the Engine Alternator will charge both.  You have a Big Boy Solenoid that connects them. Your manual does NOT tell how the system is controlled and that will be in the prints.  BOTTOM LINE.  IT AIN'T WORKING.  Two possible causes....  The Big Boy's contacts are corroded or arced and it is NOT connecting.  The OTHER issues is the Control Circuit is inoperable.

IF you have a VOM, you can test this. Find the Big Boy.  There is a picture on page 187.  With the Genny Running or plugged into shore (at least 30 Amps), the two small control wires on the Big Boy should read 12-13 VDC across them. IF there is NO voltage, then the Control Circuit or the BIRD Module or whatever is not working.  Your Prints will show that.  Monaco changed the circuits so many times and you have the last revision before it became REV, that I don't know.  BUT, to make the Big Boy WORK....you have GOT to have the control Circuit ON.  

The Big Boy should be warm to the touch and maybe buzzing if it is working.  The simple way to measure this is to use a VOM set on VOLTS and measure across the two large Terminals.  There should be less than 0.03 VDC showing on the meter.  If there is MORE, then that means that the contacts may have arced or they totally are not making a circuit.  NOW, after you measure them, with the Genny Running or the Engine Running (it should be closes either way), if you get a high reading.....then the final test.

With genny on or Engine Running....have someone hold in the BATTERY BOOST button.  There should be 12 VDC on the small wires....as in they are working.  There should be zero or less than 0.03 - 0.05 (NOT 3 TENTHS to 5 TENTHS) of a volt across the contacts.  There are YouTube videos on how to tear down and clean the contacts. Many folks do that. 

if you turn off the engine and genny, then have someone hold down the Boost....the Big Boy should immediatley go CHUNK and engage.  No CHUNK or Sound....bad coil.

Next up.  If you have the Monaco Res Refer, the manual does NOT show a LOW ENERGY SETTING.  Don't know which one you have, but the rule of thumb is this.

DRY CAMPING.  Go to or use the LOW Energy or PowerSaver mode.  TURN OFF the ICEMAKER.  That rascal will eat up current.  Use the switch on the ICEMAKER or if there is a Button or switch, turn it off.

You also have the LATEST and most UP TO DATE (per the Manual) AGS.  Learn how to use it.  Set it to come on around 11.8 - 12.0 VDC.

NOW, the RULE of THUMB.  You will NEED to have the Batteries FULLY CHARGED during the day.  If you use the LOW ENERGY OR POWER SAVE option and turn off the icemaker and don't keep all the lights on and take showers and such at night which runs the pump, you should easily get through the night,.

MY GUESS....  The Big Boy needs cleaning.....but it MUST have the CONTROL CIRCUIT working as it should.  That's about it.  

 

[TomV48]

On 10/31/2022 at 12:11 PM, Bigboy said:

I have a Monaco Knight 40pdq with 4 new 6volt Lifeline AGMs each with 330 ah. Total out put fully charged is 660 amp hrs. Over night dry camping our frig will turn off and low battery will be indicated. Everything else is turned off. Also while under power driving same issue where inverter turns off. Have to recharge with the gen set even while driving. Can the alternator be redirected to keep the house batteries fully charged. Can’t believe the electric only frig can drain the battery pack. Any suggestions appreciated. 

This is all math and don't let the math get you.  Even the GIANT 90 lbs + Lifeline GPL-6CT  6 v batteries, in a pair are only 12 v@ 300 amps rated.  So two pairs offers you 600 amps theoretical rating WHEN NEW.  With prudent battery use, 300 amps takes you down to 50% at roughly a rested voltage of 11.9-12.0 volts.  Rested voltage is not that false reading of 12.5 v you might see on the volt meter right after you turn the generator off.   That would be RESTED with no load and no charge for hours.  That false sense of the batteries being charged when you first shut off the charger is just a surface charge like a sugar rush when you have to run a marathon.  It is momentary and fleeting.  And that 12.7 volt 300 amps usable is the day they are BRAND NEW and really well topped off.    Then we run them down to 11 volt cut off a few times and bye bye 300 amps usable.  Our big rigs use a lot of power any way you slice it so Probably a bad idea to expect too much off grid time without charge, especially running any kind of compressor frig.   And even when things are charging correctly, running the generator for a couple of hours helps, but by no means will that top off the battery bank for a long night of quiet time with Res Style Frig running.   To avoid that battery struggle, we waited a 7 month plus on a back order to replace our Norcold 12 cu ft with another gas frig.  I was tempted by the convenience of a Res Frig and their ready availability at the big box store, but discouraged by all my friends, even those with the little 12 compressor units, who struggle to make it through the night on battery until the sun shines on their  solar and or quiet time is over so that the Gen can come on to make their coffee. (and don't get me started on WHY NOT A COFFEE POT on a burner versus the ELECTRIC HOG COFFEE MAKERS)

[jacwjames]

On 10/31/2022 at 9:20 PM, Rocketman3 said:

I think one of the best items to help figure out problems like this  is to install a Victron Smartshunt or BMV712. 
 

it is also really nice because it lets you know how full/empty the batteries are. Plus the time until batteries empty is really great!

Do you have a propane/electric fridge that was on electric when camping?
 

 

X2 on this.  I could not rely on my Xantrex inverter display to know the status of my battery.  I would run the generator before bed and the display would say I had ~85% battery.  Go to bed and in the AM I would have 75%. 

The BMV712 is much more accurate and shows battery draw.  I have my rig parked in my garage with power off and check via the Bluetooth connection when I go into the garage,  After a couple weeks my batteries still show 100%.  I will monitor and turn the breaker on when power gets to ~75%.  This will save me ~$1.5 per day just leaving the coach plugged needlessly charging he batteries. 

 

[Tom Cherry]

Each of us makes our own decision and such.  But at the 2018 Gathering, we had a rousing discussion on Res Refer and Batteries and capacity.  The late Bill Groves and I had done, as well as others, some extensive energy usage experiments using the KilloWatt device.  Many others chimed in.  This is the gist of my memory….as well as experience.

The Genny will not top off a 4 bank (or 8 House set) without running for a long time.  But for a 4 bank set 3 - 3 1/2 hours will get you 90+% Full Charge.  Driving or hooked up to a 50 amp service will get 100% charged.

if you have a Res Refer and use the low or energy saver mode and turn off the icemaker, then you will usually, easily make it through the night.  However, most have converted to LED as the halogen pucks are energy hogs.  Most would run the generator if they were watching TV or such as that is a power hog.  

MOST of the Res Refers will work on Modified Wave inverters,  but check it out,

If you have a Res Refer, you will need to run the Genny around 3 hours once every 24 hours….that is the rule of thumb.

Many, like me, have a On/Off simple power strip or a surge suppressor on both entertainment centers.  We switch them off when not running the Genny. YES, even in standby or OFF, the TV and such still draws some millivolts and it adds up.  Many of us have done load measurements.

i dry camped several times with the GK and we used the LED lights to play board games and never had any issues.  We would not shower at night, even with the diesel AquaHot as the pump pulls power.

I have dry camped into the fall and used the AH and never had the AGS kick in.

The OP appears to have an issue with his BIRD circuit and his later model 2012 Knight is equipped with an AGS as well.  Standard now…not optional.  Much different than the Knights of OLD with out bidirectional charging.

Exercising the batteries and keeping them at full SOC is the only way to assure you can keep a Res Refer running for the once per 24 hour Genny start.  So, until you do a load test or have the BMK from Magnum or similar, it is a guess to say that batteries are GREAT.  If a 4 bank set is “GREAT”, then following the above “rules” will work fine.
 

[TomV48]

I second the vote for a Victron VM 712.  I got sold on the Victron Smart Shunt and now wish I had spent the $80 more for the full metered 712 w gauge.

  And there is this.  We have two good RV friends with res frig.   Both had 6 wet 6v batteries and could seldom get through the night.   They were turning the frig off at bed time and back on at crack of day.   Still had to run generator 5-6 hours a day.   Now both are sporting six Battle Borns and 800 watts of solar.  Problem pretty much solved.

Edited November 2, 2022 by TomV48

[Tom Cherry]

2 hours ago, TomV48 said:

I second the vote for a Victron VM 712.  I got sold on the Victron Smart Shunt and now wish I had spent the $80 more for the full metered 712 w gauge.

  And there is this.  We have two good RV friends with res frig.   Both had 6 wet 6v batteries and could seldom get through the night.   They were turning the frig off at bed time and back on at crack of day.   Still had to run generator 5-6 hours a day.   Now both are sporting six Battle Borns and 800 watts of solar.  Problem pretty much solved.

Certainly not disputing the merits of the VM 712.  I don’t need a BKM or the Victron system….as I don’t push my system nor frequently boon dock.  But when I do, I have confidence my 4 bank set is up to the task.  I doassume it DOES tell you the real SOC, which many are not concerned with or fully understand.

Keeping on the topic, the OP has new AGM’s and a Bidirectional system as well as an AGS and probably the 2800 Watt PSW inverter.  However, his Bird system is not functional and unless he wants to upgrade, the question was “What is wrong?” and the information on how to test or have it tested should be worthwhile.

I guess we will have to wait on his feedback.

Also, your comments about Res Refer need some context.  Many folks don’t understand how to properly get longer battery life when using a Res Refer and this has been discussed and recommended here many times.  In addition, without knowing the brands and models of the Res Refers they had and whether or not they had a ECONOMY setting makes comparisons different.

The other thing, as you know, is the SOC of their batteries.  6 hours is a bit long for float charge on 6 batteries,  My 4 Trojan T105’s will get there in 3….so 4.5 would the expectation.

However, I know from load testing and following the Monaco Owners manual and the Trojan guide and talking to many experts here how to exercise them….which I do every 4-6 months, as well as how to calculate the SOC from both Specific Gravity and Voltage measurements.  Mine are several years old, but close, still to 100% CHART SOC…….when the Magnum hits “Float”.

And the group that discussed the “life and charging” expectations of a Res Refer were primarily talking about the Samsungs with the energy saving feature and the “rules” they followed.  

Therefore, my take is that the OP’s new AGM have been severely drained and before he can evaluate them, he needs the BIRD system working or if so desired, an upgrade.  We and he all also need to  understand the tricks or recommendations for maximizing battery life so we can get the expected “run Genny 3 hours or so….every 24 hours” experience.

That group of individuals had an unbelievable amount of hands on and practical experience…..which is why the Gatherings are so great.  It is amazing what you learn back and forth rather than typing and posting there.

Glad you have that system….and the Solar is unbelievable….. 
 

[vegaman19760]

I am hoping his charging system was not set for AGM style batteries and he does not have an inverter/charging system problem.  The inverter/charging system must be set up for the type of batteries involved.  Changing battery types requires changing the inverter/charging system settings.  Ours is a Magnum and they have a great customer service to assist anyone with their products.  Hope you get it solved and let us know your solution.

Safe travels to all