Foretravel Owners' Forum

Here are my symptoms and history..
I have solar so battery always charged in storage
Have minimal loads, no heater..

Left 15 days ago, battery 12.5 no load at the posts
Noticed over the next few days 12.2 after solar charging at 13.6 the next morning..
Went up to 12.4 for a couple days over nite

4 days ago woke up to 12.0, charge up to 12.5 before dark...then last 2 days 11.9
Today I woke up to 11.2?

What is going on?
Very minimal use...

Fully charge them and have them load tested.

It could be either failure of charging system or bad batteries or "all the above".

And, if wet cell batteries, you can fully charge and check them with a hydrometer (under $10).

Two places to look.  Outside and inside.  If you can disconnect the batteries from your load and each other for 24 hours, measure the voltage on each battery after the first three hours then at the end of 24 hours.  If the voltage drops after the first measurement the problem is inside your battery or batteries.  If the voltage doesn't drop then, well, you left the light on for us.

With your batteries at 12.2 your solar or any other charge source should should be charging your batteries at 13.8 to14.4 until they go to float. You might take a meter and check the voltage when your solar is in full sun in the morning. If that is all good then as others have said check your batteries.

Ok, I will let solar charge to13.6 today, disconnect check voltage after 3 hrs then check again tomarrow afternoon...

It does float at 14.2 around 4pm... but 13.6 by 1pm..

Tucson sun 900watts !

No, let's look at what is really happening:

If 14.2 at 4pm, that is very likely its bulk rate voltage.

The 13.6  earlier suggests the solar is not providing enough amps to get the batteries up to bulk rate level voltage.

To be sure the batteries ARE fully charged, voltage needs to be at the 14.2 long enough that the controller goes through bulk and absorption and into float.  Float is the indicator that the controller senses that the batteries are fully charged (drops from 14.XX to 13.YY).

You need to either use generator or shore power to supplement solar.

Again, look for when solar charge voltage (with continued good sun and not because of draw) goes to float voltage.

What Wolfe says is so true. 

Other items to check, could wiring be damaged, solar panels be dirty, any shade on the solar panels, what are batteries history of charging and maintenance? Are they O'Reilys flooded or AGM? 

What model solar charge controller are you using and how many amps is it putting in at each voltage voltage reading you gave.  Amps going in are as important, if not more than voltage.

Have you considered adding a Victron 712?  With the 712, these readings would all be available instantly on your cell phone, along with state of charge. Now that I have a 712, I thought before I was monitoring my batteries by taking voltage readings, I was not. It is so easy now, automatic and instantly on my cell.

You say there was no draw, however, could your inverter have been on all night, as it can draw the batteries down a lot by just itself being on.

I'm going to repeat what Wolfe10 said with different phrasing.

When you are charging your batteries you should measure 14.4V or so right from the get go.  If you aren't your charging system isn't up to the task at hand.  It can't supply enough current to meet the batteries need.

After no more than four hours at that "rate" your charging system should step down to the absorption charge voltage of 13.6V or so.  I put "rate" in quotation marks because that 14.4V is what is important.  The batteries will accept current measured in amperes as they need.  More at first less toward the end of the bulk phase.  With a solar charging system there isn't enough daylight to make it through the number of hours required for the 13.6V absorption phase.

Unless you don't draw any power from your batteries at night.

Ok, I will look at these..

I have a pmw 40a charge controler
I will check incoming voltage from my 900watts solar array - remember they are 2 4yrs old

Today I wake up to 11.9v. Once it's light I will check above suggestions.

To answer to your first question, "What is going on"? Based on the information you have provided. Your batteries are not fully charging on solar, and they may be almost dead. Their ah ability to store electricity may be greatly diminished.

Unfortunately, voltage will not give you an accurate picture. You also need to know the reading of amps going in, and ultimately the results of a load test.

Without this ability to test with a load tester, you at least need to start with fully charged batteries.  Charge them with a multi stage charger, until they change from 14.xx bulk or absorbtion to a float charge in the 13.xx range, and then load test. You can do this with as simple a se

Resting fully charged AGM 12-volt batteries are around 12.8-12.9 volts, and flat dead ones are at 12.0 volts, so 12.4 volts on a resting battery means it's about 50% charged.  11.9, as 12.0, also flat dead and getting damaged.

When any AGM or wet cell 12-volt battery is discharged below 12.4 volts, sulfation begins to occur within the battery. Over time, this sulfation will diminish both the performance and lifespan of the battery, eventually essentially killing it.

I believe now, as others have already suggested:
Fully charge your batteries with another known good multi stage charger, until they go from 14.xx to float in the 13.xx range, and then load test.

From my experience you will need to test with a carbon pile tester, the smaller Wallmart hand carried unit or a toaster type will not draw enough amps to get a reliable test.  I have always been able to find a proper tester, sometimes having to try a few different shops such as at a commercial marine or truck battery sales/repair shop. Do not be afraid to ask to watch while they test.  When done properly they usually will fully charge till it goes to14.xx and changes to 13.xx then at this approx 80% charged level, draw approx 400 amps, see that voltage does not go below 10.5 volts, check ending voltage, give the results.  Some badly sulfates batteries will not pass the test, with voltage during test dropping below 10.5 volts.

Not to over complicate testing, the above will work for you, the following would be the best and most accurate, which is not always practical.
"Lifeline batteries says this about testing their batteries. To determine the actual capacity of a Lifeline® AGM battery relative to its rated capacity, a full
discharge test should be performed. Although there are various battery testers available on the
market, such as carbon pile testers, impedance meters, conductance meters, and others, these
testers are not reliable in determining the battery's actual capacity. To determine the battery's
actual capacity relative to its rated capacity, use the following procedure:
1.
Stabilize the battery at 68-86°F (20-30°C) for at least 24 hours.
2.
Bring the battery to full charge as described in Sections 5.4, 5.5 or 5.6 as applicable.
3.
Discharge the battery at a constant current of 25 amperes until the voltage falls to 10.5
volts (5.25 volts for a 6 Volt battery). Record the discharge time in minutes.
4.
Compare the measured discharge time to the published 25A rating (reserve capacity
minutes) for the battery.
5.
If the battery delivers less than 80% of the rated capacity the conditioning procedure
given in Section 5.5 should be attempted and the battery capacity should be retested.
6.
If the battery delivers less than 50% of its rated capacity, it should be replaced.
However, the user should determine the amount of capacity needed for their particular
application and adjust the pass/fail threshold accordingly."

Did I miss knowing what type of batteries, Gel, AGM, wet.  Each needs a different charging profile.

Also how many batteries in bank, series, 6volt, parallel 12volt, etc.  One battery could be distressed bring the others down.

Barry , sorry AGM 8D one battery

These batteries have only had light use, been in sub 20 off and on for 8 months, always on shore and solar when in storage with sales switch off... my PO reduced phantom draws to less than 4a per day.

Have new aims PS 2000w inverter with smart low draw

Do charge controllers wear out?

Morning sun 9a, tucson.. only 12.6v at the pmw controller
Will check it again at noon !

Also found  "Equalization"on charge controller turn it on

I do have a load tester, and will provide results

Thanks Brett, Jack, Barry.. Old tool

One battery is at a max 125 useable amp hours. Coach was made and sold with 2....

He said he woke up with morning readings of 11.2, 11.9, 12.0, and 12.2 over four different mornings after charging in full sun with 900 watts solar. It is hard for me to believe he has anything near the original new capacity, and has no way to read capacity. As you say 125ah max capacity, no telling what it is now without a BMS like the Victron 712.

The 125ah would have been max when new 2 to 4 years ago, stored for 8 months at unknown charge, but lately it has been 11.2, 11.9, 12.0, and 12.2, in minus 20 degrees. With half the mornings fully discharged it would have froze at 32 deegrees.

Bob, I was surprised too, original beamalarm spec sheet shows one battery on 1994 U280.  I just can't imagine a unit going out that way though.

At least foroureye says he will post the amp and voltage reading from noon today and this afternoon.

Previous readings in morning b4 sun 11.2, 11.9, 12.0, and 12.2 over four different mornings after charging in full sun with 900 watts solar. It is hard for me to believe he has anyt

Today 11.1

250ah AGM Battery

 20 degrees Some days hooked up to shore power.. IL weather
Now in FL... past 18mo, full solar, no issues at all.

I have taken care of this battery.... the AIMS inverter/charger is 3 stage 40a

TODAY, from on board trace volt meter
AM 11.1, inverter off all nite
10am, 12.7v
Noon 13.7v

REMOVED CABLES AT 2P
Cleaned posts, cables, voltage @ posts 13.5v

BATTERY TEST, says 100amp
tester, reads low battery
Test says 10 sec load, I did it 30sec...BATTERY TESTS GOOD

Charge controler.. TRACE C40 (40A) 3 stage
Voltage from solar panels (17.5v rated)....16.7v not bad for 25yr old Siemens panels at input-output posts
Voltage to battery 13.7v at controller

LOOKS LIKE IT THE CHARGE CONTROLLER. What is a good 50a? I want to change out 2 -75 watt for a 425 watt same footprint giving me nearly 1200watts...

Charging w genny now.....

Shoot.. was wanting new BB lithium, maybe I'll just strap one in place to double capacity

Ran genny for 1 hr
14.2 volts for 30 min+
Level off at 13.6v

Checked after 1 hr rest... 12.7 volts

Problem solved?

Don't expect it to stay that way. Parasitic draw will bring it back down. Check to see what the weak link is, whether the charger, solar panel wiring, solar controller, or? Maintain float voltage and keep checking until you are sure there are no other problems.

Pierce

That would be great if you beat the problem.

Proof may be in the morning, battery should not be below 12.3 Volts, which is 50% for your agm. 

This would be with salesman switch off, both trace and Ames inverter off and any other parasitic loads off. (Best with ground cable off, so you know there are no amps being drawn.)

If resting voltage is 12.7 tonight, it should be that in the morning with all loads removed.  If it is fully discharged again in the morning, the problem is not beat. Good luck.

4am...
12.5 v ( watched tv, lights )

Still think it's the charge controller..

That 16.7V you measured at the solar panels?  Is that with the load applied?  Or is it open circuit?

If it does turn out to be your controller, I can recommend our Midnite Classic 150 as it has operated without a fault since we purchased it about 10 years ago. It was the number one controller then and still rated at the top in several solar reviews. It's also found in a lot of residential solar installations. Made in the U.S. with a 5 year warranty with 24 hour replacement and $125 max after that. It is a little long compared to other controllers so if space is a problem, perhaps another MPPT controller might work well.

Amazon.com : MidNite Solar CLASSIC 150 Charge Controller, 150 Operating... (https://www.amazon.com/MidNite-Solar-CLASSIC-150-Environmental/dp/B007PHMSN8)

Pierce

Old Tool, the voltage was at the posts on the pmw controller from the solar
The other reading was from the controller posts that go to the battery

Pierce, I will look.. mppt vs pmw.... I know the latter is more forgiving.. shade etc. I believe these 75w panels are 5 diode