House batteries don't provide power to what they should

[Dan Lane]

I have a 2001 Monaco Diplomat. I have it in covered storage with shore power attached. The inverter/charger is an ME2512 and I just replaced it about three months ago. It shows it is float charging the batteries, but the DC systems, like lights, the thermostat and other things don't come on. I checked the batteries with a volt meter and they all show as charged. The DC items just don't work. I am going to buy a hydrometer and check the batteries, but they are only about a year or so old.

When I run the engine, everything works like it should.

Is there something that, when it fails, blocks the DC power from getting to the items it is supposed to pow

---------------

UPDATE:

I bought a hydrometer and tested all four batteries. On one, the bulb barely floated and did not float on the other three. I have a 10 amp, 12 volt charger, can I use that to try to charge the batteries? If so, do I need to loosen the caps in case they generate hydrogen gas? How do I hook them up, since there are four of them?

The batteries are Interstate that i bought at Costco. The label says RC:L 105, Ah@20 hr 210. The item number is 850284.

The label on the solenoid says:
White-Rodger BM
Type: 586-105111-3 COIL 12V D.C cont.
Cust No. 586-302

[Mocephus]

Check the salesman switch. Mine is on the co-pilot panel. 

[Bob Nodine]

I agree, sounds like the 12 volt house disconnect (also known as the salesman switch) has been activated to disconnect a majority of the 12 volt house loads or the solenoid that does the actual disconnect has failed. A very common problem and there are countless posts on this subject. Many of us, myself included, have bypassed the solenoid. You simply remove the large battery cable form one side of the solenoid and put them both together on the same side or remove both cables and connect them with a bolt and then tape up the bare portion.

 

[Dan Lane]

I have been fooled by that salesman switch before, so that was the first thing I checked.  Cycled it a couple of times.  The bigger problem is the house batteries either aren't getting charged or aren't holding the charge.  The only time they appear to be getting charged is if I take it out and drive it or let it run at idle for a long time.  Can I just hook up my 10 amp charger to them, and, if so, how do I connect it to the bank of four batteries?   Or, based on the results of the hydrometer tests I described above, are they too far gone?  They are only a year old, if that.

Edited June 2, 2020 by Dan Lane

[Mocephus]

I’m far from an expert on batteries but if you are showing the batteries are fully charged and you are getting >12.4 v on each battery with a volt meter, I’d still look at the salesman switch or the battery disconnect by the battery compartment as possibly faulty.  Have you tested voltage at those switches? Even a weak battery should burn an interior light dimly.

I’ll let others give advice on how to charge the house batteries.

[bobdinsmore]

There is a design deficiency in this area: Shore power does NOT charge the chassis batteries, only the coach batteries. You need to add a Trk-L-Charge or a Trik-L-Start which provides chassis battery charging once the house batteries are fully charged by shore power. I discovered this after I bought my 2000 Diplomat, chassis batteries totally dead, replaced them only to have them quickly go dead again. The solution is inexpensive and a very simple install. There are other add-on solutions but this one has served me flawlessly for more than ten years.

Edited June 2, 2020 by bobdinsmore

[Tom Cherry]

EDITED....

Your Inverter charges the batteries.  SO....if they are charged up, then you have OTHER issues.  The Magnum charges the BATTERIES.  I would have THOUGHT that when the Magnum was supplying power....and charging....that you would have NO issues.  I wrote a summary below.....which is correct.....but here are the basic steps that I would take...

Start the MH.  Disconnect the SHORE.  NOW, use a Jumper Cable and connect the HOUSE positive to the CHASSIS Positive.  You now have at least 13.5 VDC power to the HOUSE set.  

Turn on all the lights to put on a load.  ALL the DC lights and the Thermostat should be ON.  If, so....then you have bad batteries or "Not Charged" Batteries.  Look at the print that I attached.  

You have applied temporary power to the House Bank.  IF there was (or is) a problem in the MAIN Battery (House) cutoff switch and/or the Salesman Switch....then, odds are....your 12 VDC Lights will not be OK.  Take your DVM and find a place to measure the internal VDC power.  If you pull off the cover and the reflector to a Fluorescent light, you will two incoming wires.  That is the POWER.  If you measure that, then you should see around 13.5 VDC as the alternator is putting out that much.

NOW....if connecting the house and the chassis do NOT resolve it....then you have circuit problems.  Read on down about the Salesmans Switch and the House Battery Cut Off.  They are the MOST suspect....

YOU said that the Batteries did not appear to be charged.  Read below on how to really test them.  Your small charger is going to take a long time to bring them back.  

You have ONE MORE trick to try.

Disconnect or remove the Jumper cable.  Then turn off the engine.  Then apply SHore Power.  Do you have AC on the microwave or an outlet.  NOW....look at the Magnum remote.  Are BOTH the Green Lights ON that says INV and CHRG? 

Next then do a reset.    On the Magnum inverter , usually right below the green lights (that comes on and off), there is a small buton.  This is the RESET button.  IF for some reason....the Magnum got "funky" and they do....then HOLD in the Reset Button for about 15 seconds.  This will RESET it.  Then walk inside.  Look at the Magnum.  Do you see all the lights on.   My Remote FAILED.....It would interfere with the Magnum's functions.  I disconnected the Remote.  The Magnum will have "Defaults" and work fine.  I let it set for a few days.  I also then did a LOAD test.  The batteries would drain and the Magnum would recharge.  I have a NEW remote to use.  Magnum walked me through all this...

IF you THINK that you might have a REMOTE problem.....then CALL Magnum.  They will walk you through testing.  MEMORY.....if you have the RC-50 remote.  Push the TECH button.  Then use the  dial and rotate to #4.  That might be "Defaults".  If you THEN push the knob, you should get a countdown and then it will say Defaults Loaded.  MINE would not.  

So....Magnum said to disconnect the remove (telephone cable) at the Inverter.  Then push the RESET.  That loads factory defaults.  THEN run the drain test and see how the batteries perform.  Mine calculated out perfectly.  Will install the new meter when I bring it out of storage.....

I chased this ghost for almost 3 months.  The Magnum would NOT function correctly when the power was turned off or on ....

Back to the basics.....  You need TWO trusty devices....

A REAL calibrated Hydrometer.  I use this one.  Others like the Refractometer.  This one has a "calibration" mark so that when you put in water....you see 1.000.

EZRED SP101 Battery Hydrometer

WOW...  Amazon has them on sale for $10.22....ordinarily almost $20.  You also need a Digital Volt Meter.  If you were going to really get into Trouble Shooting.....buy one with a DC Amp Scale....a Root Mean Squared Model.  Extech makes one that many use for around $135.  It is amazing what you find out....

OK....the basics....

PULL the positive cable off the House Bank.  Let the batteries "sit" for a few minutes to stabilize...

Make up a matrix and record the following.  Make a chart so you have a battery number AND a Cell number (for each battery).

You also need to check the electrolyte level.  It should be a smidge over halfway UP (between the top of the plates and the bottom of the well.  I used a wooden dowel and measured both.....then I scribed a groove on the dowel and that is my "Dip Stick".  Trojan gave away similar devices.  You can go up to maybe 3/4 of the distance.  That is where my NEW Trojans were factory filled.

Check the voltage across each battery.  Record it.  Then check the level in each cell in each battery.  While the cap is off, use a GOOD hydrometer and record the Specific Gravity.  There is a Trojan Chart that you can use on an Interstate as well.  6.37 VDC and SP of 1.277 is a 100% state of charge.  Therefore....you need to be able to read that.

OK....now that you have measured....my bet is that you have erratic readings or differences within the same batter (the SG of the cells).  That indicates that the batteries have not been exercised and need to be drained and then recharged....maybe 3 times to get them back to "Health".  Like toning or exercising a muscle.

OK....you also need to do this.  Plug in a heavy duty drain on the Inverter (with SHORE OFF and the batteries RECONNECTED).  Think of a 350 - 500 watt source...like a halogen trouble light. 

NOW...see if the batteries will handle that.  If you have the inverter putting out 115 VAC and the battery voltage drops maybe 0.2 VDC (on the Magnum remote)....and it shows INVERTING....then you seem to have decent batteries.

You ALSO need to turn ON all the interior lights.  YES....they are dim....if I read right. 

Go to the Salesman Switch Solenoid.  Use the DVM and measure across the LARGE terminals.  If you see a voltage drop of more than 0.1 VDC, then the contacts in the Salesman Switch are TOAST.    You can also do it this way.  Ground out the Black of COMMON lead on the meter.  Then measure each terminal.  One will be the incoming  (you should be able to see it running to the buss or the fuse.  That should be in the 12.4 VDC range.  NOW....measure the other side to ground.  If it is now 12.3 VDC, then you have a High Resistance situation in the Salesman switch.

The BEST THING.....GET RID OF IT.  I jumpered mine many years ago.  I recently got rid of it.  I MIGHT have to do a battery Disconnect Switch replacement.  SO, I removed it. 

NOW....there is (if my logic is correct), ONE OTHER PLACE.  You have a House Battery CutOFF switch.  Here is how MOST were wired...

The HOUSE positive goes to a large FUSE (probably round....350 A).  The other side of this fuse is connected to the Inverter.  SO....you NEVER kill the Inverter with the Cut Off Switch.

Now....the incoming (Battery Side) of that fuse is also connected to the Battery Cut Off Switch.  IF that switch has a high resistance....which is common.....then you lose power.  The switch feeds a buss with several fuses.  ONE is the Salesaman Switch.  

So, you have TWO potential high resistance points.  Contacts inside the Cut Off Switch and the Salesman relay or switch.  You have to TEST or measure the voltage across EACH component.  OR  You have to measure (to Ground), the INCOMING and OUTGOING power for each.  BUT....there has to be a SIZEABLE Load like all your DC stuff ON so that you can see the Voltage Drop.

Here is a print of my Camelot.  YOURS will be different....but the basic diagram for the Batteries to the Inverter Fuse and then to the Cut Off Switch, I'll bet....is the same....  Blow it up and look....

12V High Current Dist..pdf

[Dan Lane]

Tom Cherry,

Thanks for the very detailed troubleshooting guide.  I will try it this weekend.  I have a few questions:

1. Is the battery disconnect switch just inside the door also the salesman switch?  Or, are they different?  I Googled it and the replies could go either way.

2. For the jumper cable to connect the house battery positive to the chassis positive, how large a wire does it need to be?  Is is something I  can buy or do I need to make one?

3. Using the hydrometer I bought at O'Reillys on Sunday, I checked all of the cells.  Three of the four batteries did not have any reading in any of the cells, i.e., they would not float the  bulb.  Each of the cells in the fourth battery had a reading in the red.  I don't remember the reading, but it was in the middle of the red zone.  The water levels in all four batteries were up where they are supposed to be.  I ordered the hydrometer you recommended on Amazon and will check them again.

4. When I replaced the four batteries a year or so ago, I got the Interstate batteries they have at Costco.  Are those okay or not?  Are they trouble prone?

[fiat124man]

Interstate sells THREE quality levels of 6V batteries, Costco sells the cheapest of the three. I have them in my golf cart. NOT nearly as robust as the trojans I replaced.  I replaced the 6V

trojans in my motorhome with the premium 6V interstates(green cases). Big difference in price.  Interstate says the premium 6V are made by trojan. I paid  $160 a peace for the premium 

Interstates. They are performing very well, I boondock a lot.   Google the interstate web site.

[Tom Cherry]

8 hours ago, Dan Lane said:

Tom Cherry,

Thanks for the very detailed troubleshooting guide.  I will try it this weekend.  I have a few questions:

1. Is the battery disconnect switch just inside the door also the salesman switch?  Or, are they different?  I Googled it and the replies could go either way.

2. For the jumper cable to connect the house battery positive to the chassis positive, how large a wire does it need to be?  Is is something I  can buy or do I need to make one?

3. Using the hydrometer I bought at O'Reillys on Sunday, I checked all of the cells.  Three of the four batteries did not have any reading in any of the cells, i.e., they would not float the  bulb.  Each of the cells in the fourth battery had a reading in the red.  I don't remember the reading, but it was in the middle of the red zone.  The water levels in all four batteries were up where they are supposed to be.  I ordered the hydrometer you recommended on Amazon and will check them again.

4. When I replaced the four batteries a year or so ago, I got the Interstate batteries they have at Costco.  Are those okay or not?  Are they trouble prone?

OK....look at the prints.  The Battery Disconnect Switch is like a LIGHT switch.  All it does is toggle ON and OFF or more correctly, Energize and De-Entergize the Salesman's Switch (big Relay in the back).  The Salesman's Switch refers to the following.  High Current Carrying Solenoid or Relay with two large cables and two small control wires.  When you turn ON the Salesman's Switch on the up front console, all you do is "Turn ON" or close the contacts on the large Relay in the back.  Likewise, when you push it the other way and turn it OFF....you kill or open the solenoid or the contacts on the Solenoid.  It is like a big Circuit Breaker instead of you manually tripping it....the coil (controlled by the switch up front). turns it ON (closes) or OFF (opens).    The Salesman Switch in the circuit I sent you is controlled by the switch up front.  That Switch controls ALL your interior 12 VDC power.  If you inverter is working....then the battery charging is NOT impacted.  

A standard jumper cable for starting a car with big alligator clips is all you need.  You are NOT starting an engine or such.  It SHOULD be temporary so you can easily disconnect it.

If the Hydrometer is not reading or has almost NO specific gravity....you have depleted or run down batteries.  This is NOT good.  The hydrometer that I recommended has a scale so you can easily measure or know the State Of Charge (SOC).  Voltage of the battery (after letting it set to stablize) will also tell you, from the charts, the SOC.  Specific Gravity will tell you that instantly.

Batteries are like individuals.  Not knowing WHAT level of Interstate that you bought.....I can not comment.  However, as the previous poster said....the Trojan T-105 Batteries seem to be the most robust and also the most indestructible.  BUT, you CAN destroy them....  I did than through stupidity in a golf cart.  Ordinarily, IF a battery runs down, the electrolyte level will also be below the plates.  THEN, you fill them and recharge them.  THEN.....they MIGHT be OK (or servicabile).  The Interstates (OEM in Monaco's) which were the 225 Amp Hour units were prone to failure if they were abused.  The techs at Lazy Days said that when they had to refill and recharge a set of Interstates, the likelihood of them bouncing back was less than 10%.  But, with the Trojans....it was at least 75%...

NOW....here is what you MIGHT try....again....understand what is happening.  IF the Magnum Remote is faulty....then the Magnum MIGHT not be charging OK.  SO...if you unplug the REMOTE Telephone cable on the Inverter and push and hold the red (?) reset button....you have effectively a "non programmable" inverter /charger.  SO....then the inverter will charge the batteries without any "advice" or control from the remote.  IF you do that and the batteries come back to life....and you get them partially recharged....  THEN you can do about 3 run down sequences with a 350 Watt Trouble light for maybe 3 hours....and they should start to show less variation in the Cell to Cell Specific Gravity and the voltages of all of them should be the same.

DO THIS....if you try that.  Turn OFF all the interior TV's or Satelites.  That means either have a power strip where you can turn them off or UNPLUG them.  The standby power is parasitic.

NOW....If you have Solar....put a towel or cardboard or blanket over it.

Pull the SHORE power.  Plug in the Work Light (350 Watt Work Light).  Measure the Voltage of each Battery....or a pair in parallel.  The individual battery voltages should come down at the same rate.  When you get to 12.0  or 6.0 VDC (in Series or individual), then STOP.  Remove the work light.

Check the Specific Gravity.  Make sure that the electrolyte is full.  Wait an hours or so.  measure the voltage.

NOW....plug in power.  The batteries should come back within say 8 hours.  SO....let them recharge.  If they come back to the Specific Gravity reading of say 1.270 or higher or the 6.37 VDC, they are (or have been) rechargred.  It sometimes takes 3 cycles to achieve that.

If they NEVER come back to the 100% SOC, you can use the Trojan Chart and determine the SOC from the table....

Hope this helps.  

I would also HOPE that you have done the obvious....such as disconnecting the main positive cable (loosen) and rotate the fitting back and forth and then securly retightening.  All the studs or terminals on the batteries need that.  If you crawl under the battery box....you will see the Negative Cable.  Follow it.  It goes to a Ground Stud.  Loosen the Ground Stud....wiggle it back and forth or such to clean and polish.  You can also remove and polish or clean.  Not rocket science.

Once you have GOOD connections and the Inverter is charging.....then if the Batteries do not recharge....they are TOAST.  IT DOES HAPPEN....  

The main battery cutoff and the salesman's solenoid being bad will impact the interior voltage (dim or no power).  The inverter is connected UPSTREAM of that.  SO....if you have no power (jumpered from the Chassis), then you have an electrical component failure (or sometimes a bad cable end)...

BTW.  I bought 4 new Trojan T-105 for $115 each early this spring from a local golf cart dealer...

[eddie4ne]

 If the batteries have depleted  so low that your charger can not bring them back, Battery warehouse will charge them for you for a nominal charge.

[Tom Cherry]

3 hours ago, eddie4ne said:

 If the batteries have depleted  so low that your charger can not bring them back, Battery warehouse will charge them for you for a nominal charge.

Same deal.... MOST Interstate Battery regions have "Distributors".  These are the dealers who ship out batteries to the local merchants.  They will sell across the counter .  They do NOT do installs.  But, they do the WARRANTY.  They will load test and also do the "Rejuvenation" charging or then "warrantee" a bad battery.

I have used them, very successfully, in the past.  I use Interstates in my vehicles for starting (including MH) but use Trojans for the House.

if you are "close" to a year....they will probably help you.

BUT, if your batteries are LOW (as you said), then the Magnum will do the same.  It will throw almost 90 amps into them.  

NOW....a comment....and NOT a recommendation.  IF (and some disagree) you want a BURST of high current.....then you can disconnect ONE of the two in series.  Remove the Jumper between the two batteries (the front two or the rear).  NOW, you only have TWO batteries in the circuit.  The full 90 amps will go (the Magnum's defaults are loaded) to THOSE two.  Let it charge (if your Remote is not reading right or disconnect and use only the Inverter/charger) as I suggested) for 2 hours or maybe 3.  THAT will be the same "Three Stage High current" charge that the Distributor uses.  If that does not "restore"....then you will know.  I do NOT know (but suspect NOT) if the Interstate Distributor dumps the electrolyte and replaces.  Typically, when your destroy the coating, it flakes OFF.  THEN it settles in the bottom of the cell.  That cell is now WEAK and will not recharge to the proper specific gravity.  The crud in the bottom will eventually short out that cell.  You will have a battery that reads in the 4.75 VDC or maybe even 2.375 range.  When you have a battery that reads in the 4 or 2....ONE (or 2) cell(s) are shorted.  NOTHING will fix this....

IF you have turned the lead sulfate( ?) into a "powder" or the plating (coating of lead) on the plates has been dry or deteriorated....then there is NO fix for that.  

Edited June 4, 2020 by Tom Cherry
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