Batteries won't charge above 12.5v

[David T. Richelderfer]

The coach has a Xantrex SW series 2500w inverter.  We are parked at a RV park and the coach has been plugged into 50a power for a couple hours with the Aladdin reporting 124v to 125v on both AC legs.  Lower on the screen, the Aladdin is reporting the coach batteries ranging between 12.0v and 12.5v.  In this situation, i.e., plugged in to 50a power, the Aladdin used to show the batteries at 13.0v to 13.5v consistently.  Come to think of it, I have not seen over 12.5v in the house batteries for awhile, at least several days or weeks.  I have tried initiating a battery equalization process by going to the inverter's remote display for Generator Mode, under "Set Generator" and moving the underline cursor to "EQ".  The yellow LED labeled "Bulk" comes on blinking slowly as it should indicating the process has been initiated (I think).  The "Set Absorption time" and "Set Equalize time" settings in the battery charging (10) menu heading are both set to "02:00".

I would have thought that once the equalization process has begun one of the Aladdin's AC Legs would show a high rate of power usage for charging the batteries.  Also, I would have thought the DIS/CHG rate for the coach batteries would show a rather high CHG rate.  BUT... at this moment, for example, the Aladdin is reporting the coach batteries at 12.5v with a 6 CHG rate... and this with the yellow Bulk LED blinking showing the equalization process is going.

Something is wrong here and I have no idea what or where to look....

[David T. Richelderfer]

Update - My generator just started up automatically.  Boy o' boy, something's wrong!

[Gerald Farris]

David,
You can try to reset your inverter if possible (look in the operator's manual). On my Prosine inverter, you reset it by removing all power. However, it sounds like it is time to repair or replace your inverter, assuming that you do not have a tripped inverter breaker.

Gerald 

[William Jordan]

 When you were in the generator setting I'll bet you turned on the autostart function on the generator this happened to me it's easy to do. Also I would check the settings on the inverter part of the control panel , you can set the charge rate  for absorb and float equalize etc I would look and see what the settings are. If this is a trace panel the. Complex manual is avail online get it. Good for an entire evenings reAding

[Keith Moffett]

David
While we have a Magnum inverter now that is about two years old, the theory is the same as yours more or less.

We were getting all kinds of odd numbers on the monitor panel. I was thinking the new inverter failed or the batteries just died neither of which made much sense.
The problem turned out to be the temp sensor on the batteries.  Because it was bad the inverter was getting bad info.
On ours the temp sensor is a black rectangular item attached on a battery with the cable.  It is connected to the inverter via a phone connector plug.  There is a connector jack in the battery compartment for convience.
To test this use a multi meter while on shore power.  Check he charge rate on the batteries then unplug the temp sensor and check again.  The charge rate should now be normal (+/- 13.5V).
We ordered a new one from Magnum for under $30 and install time was 5 minutes.

Good luck

[David T. Richelderfer]

I seem to be able to get the house batteries up to 12.5v, but no higher.  And this only when I initiate the battery equalization function on the inverter's remote panel.  As long as that blinking yellow BULK LED light is blinking on the remote panel, then the inverter will provide charge to the batteries, but only to 12.5v.  For example, when I checked the batteries' charge level first thing this morning at 6 am, the charge level was 11.9v.  I initiated the equalization function on the inverter's remote panel and quickly saw a charge rate of high double digits, but as the batteries move up to 12.5v the charge rate moves down to single digits.

At dusk last night I went to check the batteries.  They are all cold with no sign of warming as I would expect in conjunction with an equalization process.  Also, I saw the Battery Temperature Sensor (BTS) was not attached to a battery.  It was loose, the tape had come off the battery, and was simply standing up laying loosely between two batteries.  I re-attached it best I could with duct tape back onto the side of the interior battery - the same battery it had been attached to.  As noted above and witnessed by the batteries' voltage first thing this morning, re-attaching the BTS made no difference.  Of course, that doesn't mean the BTS is good or bad.  I will take a detailed look per Mr. Moffett's suggestion after it gets light outside.  I will also try turning off all power to the coach in an attempt to reset the inverter as noted by Mr. Farris.  I found no mention of breakers or reset buttons, other than to reset to factory defaults, in the inverter manual.

At this point with it being dark outside yet, I am going to use my time to research new inverters on the internet.  So, I have some questions - 1) what is the preferred make and model for my application?  I assume Magnum but what model.  The inverter currently installed is a Trace Xantrex SW Series Inverter/Charger, I believe 2.5kw.  Does a 3.0kw make sense given we push the limits of this one occasionally?  2) Can an inverter be purchased that just slides in, meaning the new one uses the same remote panel, etc., to make installation very quick and simple?  3)  We're parked in Fredericksburg, TX in the newly opened Quiet Creek RV Resort.  Anyone know of a reliable repair company, probably mobile capable, in the immediate area?

Thanks in advance...

[Fred Brooks]

           David,

    What is the voltage at the battery cables coming off the face of the Xantrex? Have you checked the 200 amp in line fuse between the batteries and the Xantrex? The BTS mounted to the batteries only tells the charger when to back off the charge rate if they are hot.
   In the event the charger has expired, Magnum inverters are almost bullet proof and the swap out is pretty straight forward. The ratings are based on inverter watts output so ask yourself how often will you try to run the coach at capacity rating. The MS 2812 is a pure sine wave but runs about 2000.00 with a retail value of 2479.00. The remote panel is about 250.00. Regards, Fred

[Fred Brooks]

               David,

      Another thought concerning the charger/inverter, The charge logic is controlled by the small PC board mounted behind the soft buttons on the front. The board is about 300.00 to 350.00 and the labor should be about 3 hours to change it. You can call Xantrex and inquire who is the closest dealer who stocks the part. In the mean time, put an automotive battery charger on your house batteries until you sort this out. Fred

[Joel Weiss]

David,
You can try to reset your inverter if possible (look in the operator's manual). On my Prosine inverter, you reset it by removing all power. However, it sounds like it is time to repair or replace your inverter, assuming that you do not have a tripped inverter breaker.

Gerald

Our Xantrex went into this same failure mode a couple of years ago.  For a month or two I was able to do what Gerald suggests and it did work, but the problem wasn't really going away.  Finally, I bit the bullet and installed a pure sine wave Magnum MS2800.  Problem solved

[William Jordan]

Be aware that the trace inverter while no longer made can be repaired probably at a much lower cost than a new magnum and is much more capable than any but the high end magnum. It was ahead of its time. The trace is highly sought after by the solar crowd so don't just "give it away" check eBay and solar sites and you'd be surprised
You can remove 12 volt and 110 power at the circuit breaker boxes and crawl in the bay and unplug the temp sensor from the inverter itself
I had also heard or read someone else say the temp sensor could cause that type problem BTW  it doesn't need to be attached to the battery just laying in between the batteries is good enough.
What are your equalizer settings ? Are they set above 15.3 volts ? They are adjustable and could be set wrong ... Like 12.5 for example.
When I put 600 watts additional solar on I looked at replacing it and was told to keep it as it was better than the magnum I was looking to replace it with

[David T. Richelderfer]

My inverter/charger is a Xantrex Trace SW2512MC and has a remote panel in the coach's cabin.

I spent most of today either on the phone talking with Xantrex technical staff in Burnaby, BC and Southern California, or putting my multi-tester on various points checking voltages.  What I have learned is the problem is likely internal to the inverter/charger.  The house battery bank at the batteries reads 12.8v to 12.9v while at the same time at the inverter/charger DC input points only 0.02v less (12.82v at the batteries vs 12.80v at the inverter as one example), so the battery bank was at near full charge and the cables from the battery bank to the inverter are not the problem.  AND while at the same time both the Aladdin "Coach Electrical Status" screen AND the inverter's remote digital screen show identical readings for the house battery bank some 0.4v lower.  So... the inverter has a conflict between the actual battery bank voltage versus what it is reporting to the Aladdin and the inverter's remote screen.  The way I interpret the problem is part of the inverter thinks the battery bank is charged up, but another part of the inverter thinks the battery bank is not charged up.  Thus the conflict in its internal workings.  This inverter does not have a reset button to jump-start it, nor does powering it off and on jump-start it.

I called the closest Xantrex repair shop from me going to the West (which is in Tucson) to discuss having my inverter repaired.  My inverter has only one internal circuit board and a replacement board IF one is available will cost $1450 plus estimated $250 labor to install.  All in for a repair would be $1700 or so.  If the replacement circuit board is not available, then a new replacement inverter (Xantrex Freedom SW 3000w) would cost $2350 plus $300 for a remote plus estimated $450 labor to install.  All in for the new replacement inverter would be $3100 or so.  This repair shop in Tucson also repairs and sells Magnum inverter/chargers, and has refurbished inverters too at much lower costs.  So that may also become part of the discussion when and if I go there.

I have remaining about 2/3rds of a year on the 4-year extended warranty from when I purchased the coach in August 2012.  The warranty has a $500 deductible per repair-visit.  Also, I think I need to get the coach's windshield re-set because it leaks a bit and is showing ever larger gaps on both top corners.

[Jerry Emert]

David, if you need a board a friend of mine has a new one.  He used to be a xantrex tech but was screwed by their warranty dept so he quit dealing with them.  He may work on price better than $1450.00 you mentioned above.  Let me know if you need his number.
Jerry

[Edward Buker]

David,

I thinks the differences in voltage levels between the battery terminals and the inverter terminals is negligible and really have no meaning other then it implies that the batteries are in good shape and not drawing a lot of current due to a bad cell. If significant current was being supplied the voltage would be less at the battery terminals due to voltage drop in the wire run from the inverter. If you power up a lot of 12V loads like the Halogen lights is there any response in the current being supplied by the inverter/charger as shown on the inverter/charger readout panel or with a raise in voltage level at the battery posts?

When you try and reset the inverter by un-powering it you have to remove the AC feed from the coach main breaker at the panel or the main power cord and also disconnect the battery feeds by shutting off the battery bank switches for 30 seconds. Just wanted to pass that along just in case that was unclear.

I am not sure what the allowed tolerance is in the readouts between the battery post and the readout panels. They would not concern me that much if the voltage at the battery terminals was higher in the 13.5V range and the current being supplied by the inverter charger varied on the readout with the load demand. It may very well be a charger failure, as you suspect, but check to see if the current load/supply varies on the charger/inverter panel as you vary the load. If it has failed, while I had a warranty, I would be looking into the Magnum line given the good reliability reports from others.

Later Ed

[David T. Richelderfer]

Ed - First thing yesterday (Monday) morning I powered off everything - pedestal 50a, inverter/charger, coach battery disconnect, etc., everything except the chassis battery disconnect and let it sit for awhile, then reconnected them all.  No change.  I spent most of the early day yesterday (Monday) on the phone with a technician in Burnaby, BC and he later turned me over to an engineer in California.  They had me checking several things with a multi-meter around the battery bank and inverter.  The engineer had me reset the inverter/charger to factory defaults, then we went through the inverter settings so that he was happy with them.  We then checked the battery bank voltage and compared that to the Aladdin's and remote panel's reported battery bank voltages.  The battery bank's actual voltage shown on the multi-meter was about 5 volts higher than the Aladdin and invertor remote panel were reporting.  Both the technician and engineer diagnosed the inverter has a problem.

Later yesterday evening and all day today the difference between the battery bank voltage versus the Aladdin's and inverter remote's reported voltage for the battery bank is 7 volts to 8 volts difference.  When I was talking to the technician and engineer yesterday the highest value I could get on the Aladdin and inverter remote panel was 12.6 volts... and that after the inverter charge amps (as reported by the Aladdin) had gone to near 0 (zero), which means to me the charging function has completed its job.  Last night and today the highest value I can get on the Aladdin and inverter remote panel is 12.3 volts... and again that is after the inverter charge amps (as reported by the Aladdin) has gone to 0 (zero).

I have had a portable charger on the battery bank all day set to 2 amp charge.  Right now, just after returning home from being away for six hours the portable charger is reporting the battery bank is fully charged, and the Aladdin is reporting the battery bank at 12.3 volts with a 4 amp charge rate.

I am not an electrician by far, but this ain't right.  In the past when the battery bank was fully charged the Aladdin reported to me something like 13.3 to 13.4 volts.  I have not seen over 12.6 volts for several days.

[Edward Buker]

David,

Obviously the 7 to 8V difference is clearly wrong. Also the fact that you cannot get 13+V on charge function is wrong. Your reset routine was correct and that exercise had no positive change in the results.

Dave I think you can be very confident that this charging system has seen its better days. There is little more that you can do to try and repair or restore function from your end so turning your attention to warranty coverage and the best choice in a new system is energy well spent in putting this repair behind you. You have done your homework...

Hopefully the next steps will go smoothly.

Later Ed