Batteries float charging at 14V

[Bob R]

My domestic batteries are charging at 14V when I’m driving. These batteries boiled a good portion of the electrolyte out of the battery into the battery tray. My solar charger was showing 17V. I removed the fuse for the solar controller and it is still showing 14V. Is there an adjustment on the voltage regulator that I can change to lower the charging voltage from the alternator? I’ll add water to the house batteries so they won’t go dry. 
This is a 2005 Dynasty with the 400ISL engine.

Thanks for any advice you might have. I’m in Gallup, NM so service facilities may be sparse.

Bob Raffety

[Tom Wallis]

14 volts should not boil your batteries unless one of them is defective. 17 volts would definitely be a problem though. You need to check the voltage at the batteries with a voltmeter and see which it is. If the charging voltage at the batteries is less than 15 and the batteries are boiling then you need to look for a shorted cell. Usually it will be the cell that's not boiling. Or if the disconnected  voltage on a battery is 2 volts low. If the charging voltage is over 15 volts then whether it's the alternator or the solar that needs to be fixed.

[Tom Cherry]

15 minutes ago, Bob R said:

My domestic batteries are charging at 14V when I’m driving. These batteries boiled a good portion of the electrolyte out of the battery into the battery tray. My solar charger was showing 17V. I removed the fuse for the solar controller and it is still showing 14V. Is there an adjustment on the voltage regulator that I can change to lower the charging voltage from the alternator? I’ll add water to the house batteries so they won’t go dry. 
This is a 2005 Dynasty with the 400ISL engine.

Thanks for any advice you might have. I’m in Gallup, NM so service facilities may be sparse.

Bob Raffety

Ok…little bit of understanding.  Tom W’s comments are good, but read this as it specifically pertains to our motor homes and they are not your usual systems.

First, there is no adjustment on the built in voltage regulator on the 200 amp Leece Neville alternator.  My charging voltage is always in 13.8 - 14.0 range….snd that is a digital display on the instrument cluster,  i do NOT have an Aladdin system.

Second, the house bank is charged via a direct connection to the house from the engine’s alternator circuit via your BIG Boy Boost solenoid.  Conversely, when you are plugged into SHORE, your Inverter will also charge the Chassis.  That is called BI-Directional Charging.  There is, i am pretty sure, a custom built circuit board that controls when that happens and the parameters.  When the “charging side source”….which is actually the voltage and the “need to be charged side” battery voltage get within some preset limits and both are properly charged, the the Big Boy opens.  Likewise,  if one bank is really low, then the Big Boy opens to keep the “uh oh” bank from killing the other.  

OK….again real world and practical. IF I have the Genny ON….and the Magnum is “bulk charging”, it is NOT unusual to see my Engine volts at 14.5 or so.  Lots of times, I will turn on the Genny and have my DW read the Magnum.  If the voltage is high there (Bulk or just starting to begin the second phase “Absorb”….it will be high.  As the house gets or starts to get fully charged, then the Engine voltage will start to drop.  THEREFORE, I know my Big Boy and it’s controller are working.  Sometimes when the Magnum reaches float….it will be a tenth or so higher….then when I stop the genny, it comes down a smidge.  That is my “simple” test…

Third, The charging amperage from the solar is probably not sufficient as it may only be 5 to 7 amps to “fry” the cells.  But, if you disconnect the solar panel wires from the controller, that eliminates that….do that first….but don’t expect any major change.

FOURTH.  not talking down to you, but are you sure the battery electrolyte level is correct?  The generic answer or advice.  Look with a LED flashlight into a cell.  Fill the cell to halfway between the tops of the plates to the BOTTOM of the well.  SOME folks think MORE is better.  They fill halfway UP the well.  This will cause a mess…don’t ask me how I KNOW.  After reading a lot and helping and learning here and talking to others….I FIGURED IT OUT.  LOL.  Actually, there is a Battery 101 in the files that explains this and a lot more.  

MY EASY METHOD.  Use a 1/2” dowel (preferably hard wood) about 6” long.  Drop it into a cell.  Mark, with a sharpie or pencil, the TOP of battery cell plastic ring.  OK, using a flashlight, pull up the dowel to where the bottom is JUST at the same level as the bottom of the well in the cell.  Mark the dowel using the same top of the battery cell ring as you did when it was in and on TOP of the plates.  Measure the distance from the two marks…use the 1/32” scale on a tape.  DIVIDE BY 2.  NOW add 1/16 or 2/32 to the distance.  Measure UP, from the bottom of the dowel that dimension….probably 5/8” or so…. Make a mark there.  THAT is the proper Electrolyte fill level.  Then use a knife or a triangular file and scribe a line around the circumference of the dowel.  BINGO…a Battery DIP STICK.  You just drop it in….take it out….adjust (add) a SMIDGE…wipe (use a paper towel and don’t dribble on your best jeans….again…I KNOW) and retest.  I do this all the time and quit “peering” into the black deep hole,  BTW…after learning to fill properly and use my dipstick I get up to 6 -7 years out of my Trojan T-105….they are the equivalent of the cheap Interstates that were OEM.  So….make sure you are NOT over filling.  The 1/16 that I added is a smidge of an insurance…but I NEVER boil or have messed up my “refurbished tray”.  So I KNOW.

OK….having said all that.  When you have a shorted cell in a battery, that is a BIG resistor.  So, the current in that set of two is spiking.  From a real/testing standpoint, the current flowing through each set of batteries (2 if you have four or 4 if you have eight) will be equal.  YES, I was once an Electrical Engineering student…and aced my DC courses.  BUT….a shorted cell….depends on how many and where.  

OK…WHAT IS A SHORTED cell? Again…for those that might not understand.  If you remove the Jumpers from a charged set (pair) of 6 VDC batteries, then the Voltage (let it sit for a while) should be around 6.2 - 3/4.  BUT even really run down…it will be above 5.7 VDC.  NOW, there are 3 cells.  So each cell, if fully drained will be 1.9 VDC(5.7 / 3).  You CANNOT measure each cell.  If you have a battery that reads around 4.X VDC…a shorted cell…2.X….TWO cells.  The lead oxide on the plates has flaked off.  That coating is now piled up in the BOTTOM of the battery.  OPPS…the cells do NOT touch the bottom….then the excess (should be NONE THERE) flaked off lead oxide has “shorted” that cell.  It has ZERO VOLTS….so the battery reads only 2/3 or 1/3 of the normal, even drained a lot, voltage.
 

OK…that’s the background.  Check the electrolyte.  Measure the individual voltage of each battery (JUMPERS OFF).  If you have a shorted cell…there ain’t no fixing it…. If you luck out, assuming you might have a shorted cell….don’t replace the jumper.  I had two GOOD and two BAD.  I hooked up the good and left the bad out for s while and then bought 4 new Trojans…

Read…test….observe….get back with us…

[Bob R]

Thanks Tom W and Tom C!

I appreciate your comments! I’ll check for a shorted cell on the four batteries. That could be the problem.

I removed the solar controller supply fuse this morning. I didn’t notice any big change in the charging voltage during my drive from Gallup to Cortez. The charging voltage measured by the Aladdin was still 13.9 - 14.1V. This seems to agree with your observed charging volts on your RV. I didn’t run the generator so can’t compare those conditions with your experience.

I understand the electrolyte level information you included. Early on I was pretty naive about battery acid levels. I filled my batteries to a level much too high. I reconditioned my battery tray as a result. But all that said I might have overfilled the batteries before beginning this trip! I appreciate the tip about the battery acid dip stick. As soon as I am able I’ll implement that advice.

I’ll let you know what the final solution was in a few days.

Again, thanks to you guys for the help. I feel much better about this situation than before.

[Rikadoo]

Mornin all what a wonderfull day👍 So as my mornings go, i always enjoy getting up having my coffee reading the latest posts. On this one i agree that the 14 volts is within range, normally when checking charging systems the industry standard for years has been 13.8 to 14.2 for non computer controlled systems, and that i ALWAYS check voltage at the end of the system “AKA the battery”, AND in the automotive world if i had a vehicle come in an the battery was getting 17 VDC i would shut it down an start finding the problem, cause that battery is gonna be hot an can go boom if it is gassing. However that said there was a mention of adjusting the voltage of the alternator, like i said the output is with in range, BUT if you ever need to leese nevill alternators are the only systems that offer that option. There is a condition that you MUST do prior to performing the adjustment, an that is you must use a plastic screwdriver, or at least one that wont short out. On the regulator there is a “plug” that has to be removed an under it is a adjustable potentiometer, an with the engine running slightly above idel, while watching a voltmeter turn the slot one direction or the other to increase or decrease the voltage your wanting. They “ the alternators” were designed this way cause they are used on many HD applications that require different voltage requirements. In the pics you can see the little white plug.

[Tom Cherry]

20 minutes ago, Rikadoo said:

Mornin all what a wonderfull day👍 So as my mornings go, i always enjoy getting up having my coffee reading the latest posts. On this one i agree that the 14 volts is within range, normally when checking charging systems the industry standard for years has been 13.8 to 14.2 for non computer controlled systems, and that i ALWAYS check voltage at the end of the system “AKA the battery”, AND in the automotive world if i had a vehicle come in an the battery was getting 17 VDC i would shut it down an start finding the problem, cause that battery is gonna be hot an can go boom if it is gassing. However that said there was a mention of adjusting the voltage of the alternator, like i said the output is with in range, BUT if you ever need to leese nevill alternators are the only systems that offer that option. There is a condition that you MUST do prior to performing the adjustment, an that is you must use a plastic screwdriver, or at least one that wont short out. On the regulator there is a “plug” that has to be removed an under it is a adjustable potentiometer, an with the engine running slightly above idel, while watching a voltmeter turn the slot one direction or the other to increase or decrease the voltage your wanting. They “ the alternators” were designed this way cause they are used on many HD applications that require different voltage requirements. In the pics you can see the little white plug.

On my Camelot....and I THINK many other models, including the Diplomat....have a 160 Amp Alternator. There were a few earlier NON Dynasty....maybe a few models of the Windsor, that have the upgraded 200 Amp LN.  All Dynasty and up have it unless the higher, very high ends had a 240 or maybe a 260 A model for some engines and maybe an ALL ELECTRIC MH....

I have the LBP-2180 and/or including the LN info....110-912.  The Regulator for it is the LN Regulator number 8RG3078 or maybe 8RG3102S....

Doing a search for it and such provided the following. Show the pictures and how to install and it appears to be an external attached, but is internal. Note the "hole"

https://www.elreg.com/wp-content/uploads/pdfs/8RG Regulator Change Out Procedure .pdf

OK....I THOUGHT it was NOT adjustable....but then kept digging.  IF I have the 8RG3078 OEM Regulator, It IS adjustable, but it does not look like the one in your picture or used on the Monaco Models (LBP Series).  That Regulator 8RG3078S maybe or supposedly came with the OEM, but I could not verify that on the LN site.  

https://www.peivinlookup.com/Category/8RG3078S/Alternator-Voltage-Regulator

There IS an alternate Regulator or "Leece Neville DIRECT REPLACEMENT....that will also work and is sold for the LBP series....IF I read correctly. it is the 8RG3102S.  IT IS NOT ADJUSTABLE.

https://www.peivinlookup.com/Category/8RG3102S/ALTERNATOR-VOLTAGE-REGULATOR/Alternative

So, I guess it depends on which regulator is on the LN LBP (mine is the 2180 or AKA 110-912) that one has....and they look identical, except the hole on the 8RG3102S is a "Fake" or used when they use that housing for the adjustable one. 

Bottom LINE....one must have the correct PN info....which is available on the build sheet and should be verified from the Alternator....then also determine WHICH regulator that it is.... Here is the LN current listing for my alternator....it does have the external, bolt on Regulator, but there are TWO different versions....and you must know WHICH you have.  They look the same....as they use the same Regulator housing.  I did not do a screen shot as I have two monitors and get BOTH screens.  Click on this....there are several photos of the regulator, which I know, look like mine from my cursory inspections...

https://prestolitesuperstore.com/Category/LBP2180GH/Prestolite-Leece-Neville-LBP2180GH-New-Alternator-LBP-Series-Pad-Mount-type-12V-160A 

That's what most of the LN alternators used on the Monaco's should look like....Hope this helps and ties down what we are discussing....

 

[Happycarz]

From what I’ve seen of the Monaco alternators, they used mostly the 160a and 200a alternators. 15-20 years ago you could buy genuine replacement parts from Prestolite/Leece-Neville. Not any more. Those alternators came with what was called an internal regulator, as it was bolted onto the alternator.  

There was the adjustable one, #100650, and the non adjustable one, #102200. These are no longer a service item from Prestolite. That leaves you to source them aftermarket. 

I carry a spare alternator, spare alternator bearings, brushes, and spare Transpo adjustable voltage regulators. I’m just a good Boy Scout!  
This is the same voltage regulator as in Rik’s picture above.

When I bought my spare alternator from NW RV Supply years ago, I saw it had an Leece-Neville adjustable regulator on it. Great, I’ll put one on my factory alternator. 13.8-13.9v was too low for me. I like the voltage set to 14.2-14.4v.  No longer a service part. Checking online, I see a seller with an adjustable Transpo voltage regulator. By the time I got around to ordering it, only the non adjustable one was listed. I sent the seller a message and he got me three. He still an eBay seller. 

After removing the alternator, I installed the adjustable regulator, installed the alternator back in place and dialed it in. Adjusting it is a real treat with the regulator pointing down and a spinning belt nearby. But I got it done. My Aladdin shows 14.1v, a bit higher at the batteries.

That Transpo has been working for years. No complaints.

The pictures below are of the original Leece-Neville voltage regulators. Both types. The Transpo adjustable I use is in Rik’s picture.

 

 

 

[Bob R]

I have come to the conclusion that I may have overfilled the batteries. They have not shown any signs of boiling over again. It may have been that the vibration of traveling down some of our interstate highways may have contributed to some of the spillage.

Thanks for all of the responses. I learned a lot of information that may help me in the future.