Community Forums

3xbear · 05-17-2017, 06:26 PM

No matter how much you watch over your coach, a storage facility is bound to screw things up. This Monday I found my coach, unplugged and with the main power switch on the off position, and had been that way for 3 days. The batteries read "low" at 12.6 volts. Immediately replugged to 50A, and gave them a piece of my mind. Upon re checking today, still plugged, it's reading "full charge," at 12.6 volts. The question is, is the battery bank fried? It used to read 13.1-13.2 before this mess.

Kiawah · 05-17-2017, 06:43 PM

If your inverter was off, then the batteries should easily have sat for those 3 days with no problems. 12.6 is 90% charge, when batteries are at rest.

But it should have charged up in 24 hrs. Makes me suspect whether the converter is turned on, and has a path to the house batteries.

Is your converter turned on?

WILDEBILL308 · 05-17-2017, 06:47 PM

Quote:

Originally Posted by 3xbear

No matter how much you watch over your coach, a storage facility is bound to screw things up. This Monday I found my coach, unplugged and with the main power switch on the off position, and had been that way for 3 days. The batteries read "low" at 12.6 volts. Immediately replugged to 50A, and gave them a piece of my mind. Upon re checking today, still plugged, it's reading "full charge," at 12.6 volts. The question is, is the battery bank fried? It used to read 13.1-13.2 before this mess.

12.6- 12.7 would be a full charge. The 13.1-13.2 would be the voltage when charging. Here is a good link on battery information.
https://www.batterystuff.com/kb/arti...ry-basics.html
Bill

Daveht · 05-17-2017, 06:47 PM

They will be fine. I had voltage showing 6 volts and the batteries came back. That happened a few times before I installed solar panels. Now all is fine. Don't worry the batteries are stronger then you think!

Skip426 · 05-17-2017, 06:55 PM

A three day disconnect , and battery bank down to 12.6v , would not indicate any real long term battery problems to me .
Below 11 volts maybe; even then good batteries should come back from a single discharge cycle.
As far as you current reading of full charge at 12.6, when you used to get a 13.1. That's a little confusing .
To me a 13.1 volt reading means you were seeing the inverter/converter/charger in float charge mode , not an actual battery state of charge read out.
More info on battery state of charge on this site.

The 12volt Side of Life (Part 1)

3xbear · 05-17-2017, 07:08 PM

True, that 13.1 read was when I was on the road, inverter on and solar going. I do have solar which, may have saved the batteries?

twinboat · 05-17-2017, 07:25 PM

You can draw a true deep cycle battery down to 80% DOD, 11.60 volts, 500 times.
You can draw the same battery down to 50 % DOD, 1000 times. That's what DEEP cycle means.

Just charge them back up and if they are any good, you'll be fine.

Those of you who think different need to dig into the specs of deep cycle batteries.

For those who use dual purpose, RV/Marine batteries, figure 300 to 500 cycles to 50% DOD, ( Depth Of Discharges ), if we'll cared for.

Store them discharged for weeks or months at a time and throw them out in 1 to 2 years.

OldBeaver · 05-17-2017, 07:31 PM

I had my batteries run down for a while due to not being familiar with the RV after buying it.
Basically I parked it but something was left on that drained them dead and they stayed dead for few weeks. Not exactly sure how long.
After that they did not want to take a charge.
I bought this little thing and had the 4 batteries back to life after a few days:
BatteryMINDer Charger/Maintainer/Desulfator System- Model# 1500

I got mine from some place on eBay.

After getting the deep cycle rv batteries back to life, I did a little experiment. I put it on a battery that has been sitting dead in my garage for at least 5 year (could be 10). This was a battery that got pulled out of a vehicle due to no longer holding a charge.
The BatteryMINDer brought it back to life as well..... or least enough to read 12 something volts with a meter and maintain that reading when I check it a few days later.
I will admit that I did not test that battery's capacity as it simply sat in the corner after being charged.
The rv batteries however did get used for a couple months aftewards and held up fine. They were fully functional when the rv was put in storage.

Matt D · 05-18-2017, 04:57 AM

I think you're fine.

As Twinboat says, there is a lot more headroom for use with these batteries than most utilize.

When we went to look at our coach, the batteries were completely discharged, showing some silly low voltage like 5 or 6 volts, I don't remember what.

I knew they were as dead as a doorknob.

I spoke to the dealer, Entegra, and the battery manufacturer. Everyone stated "they are fine, charge me and use em."

I did my best to replicate a timed load test from fully charged, the results lined up with undamaged batteries.

The batteries continue to perform as expected. Our batteries are Discover L16 AGMs. I suspect flooded lead acid batteries to suffer in the same scenario.

-Matt

YC1 · 05-18-2017, 05:13 AM

Use a voltmeter on the batteries directly. 12.6 is not fully charged. That voltage won't damage them but they are not charged fully.

If you had a reading of 13+ before then something is not right. Going down the road the alternator will be 13 + . Unplug and start the coach. You should see the voltage go higher that 12.6. Give it a couple of minutes of course.

If you have any decent solar size the voltage from it could be causing a false reading from your charging system and making it say it is fully charged.

If you find the voltage is indeed 12.6 at the batteries, turn on a bunch of lights or your inverter and run the microwave for a couple of minutes. This should kick your charger into high gear.

Kiawah · 05-18-2017, 08:58 AM

Quote:

If you find the voltage is indeed 12.6 at the batteries, turn on a bunch of lights or your inverter and run the microwave for a couple of minutes. This should kick your charger into high gear.

Be sure to disconnect from shorepower first, otherwise your inverter will just be passing the shorepower thru to 120 vac devices. If you disconnect shorepower, then the inverter will run and indeed suck the 12.6v down.

Make sure you disconnect the solar controller from your batteries, you don't want any interference from that perhaps giving false readings of battery voltage. Want to make sure the converter to battery charge process is working correctly.

The converter should have charged the 12.6v (90% SOC) up to full charge. So as I posted before, I believe you need to check why your converter doesn't appear like it's turned on. Perhaps power it off, then power back up again.

757driver · 05-18-2017, 09:23 AM

Time to clear up some confusion here.

Entegra coaches do not have a converter, it is not necessary. All charging is done through the inverter(s).

A Discover AGM battery is not fully charged at rest with an indicated voltage of 12.6v, at rest it is fully charged at 12.9v.

If your batteries were showing 12.6v PRIOR to plugging into shore power then your batteries were discharged very little (about 12-15%) and are just fine.

The reading of 12.6v the next day while plugged in is also perfectly normal under the circumstances. The key to this is where you mentioned the batteries showed Full Charge. On the Magnum inverter if Final Charge (SET 9) is set to Multi then after being in Float Charge for a period of 4 hours the Chargers shut off and the Magnum remote panel shows Full Charge. The Chargers wait until they see a voltage of 12.6v and then they turn on with a float charge for another period of 4 hours. I will bet that if you monitored the batteries for a few more minutes you would have seen them start charging again and the voltage increase to around 13.6v.

757driver · 05-18-2017, 09:27 AM

Fred,

After re-reading your post I am curious as to what battery type you have set in your Magnum remote panels? It is located under SETUP 4.

Kiawah · 05-18-2017, 10:13 AM

Quote:

Entegra coaches do not have a converter, it is not necessary. All charging is done through the inverter(s).

757, this is a Magnum unit (like an MS2812), with an RC-50 (or ARC-50) remote panel, right?

The Magnum unit has three functions, a converter(charger), an inverter, and a transfer switch. There are separate settings for the converter and inverter. You can turn the converter on and off, or the inverter on and off. There are configurable settings for the converter, and other configurable settings for the inverter (and AGS).

The converter takes 120vac and makes 12vdc. The inverter takes 12vdc and makes 120vac.

The flooded absorb voltage is 14.6volts, and the float voltage is 13.4. AGM is 14.3 / 13.1 It should have had plenty of time to get to 13+ volts.

I guess it's possible that the batteries were charged all the way up, then went into saver mode and were discharged back down to 12.6 (and not shifting back into float mode yet), and the OP didn't see any of the higher voltages during this process.

Still want to see the batteries successfully going thru a charge cycle to know the converter/charger is working and taking the batteries up to 13+ volts.