OOPS and Diagnosis help needed.

[camaraderie]

UPDATE...
At least for the time being my problem seems to have cured itself. I left the batts on the charger for the last 24 hours and when I came back today...I got 13.6V at the battery terminals AND at the converter...so the mysterious voltage drop has disappeared! I'm thinking that the flat batteries (for those just joining the conversation...those were MY fault) presented too low a voltage load for the converter and battery center circuits to respond to properly... but that once I had sufficient charge on the batteries...normal charging resumed. Since it appears that I am in absorption stage at 13.6V...I plan to leave them on the converter for another day and hope we achieve float voltage.

Now I've likely damaged the batts by discharging them... so after float is achieved, I will remove the negative wire to fully isolate the batts and wait 24 hours before testing to see how much capacity I lost. Since we don't boondock at all...as long as the batts remain serviceable and functional when plugged in.... I'll keep 'em.
There was no boil off and plates were never exposed so I am hopeful. Will let you all know the results of that test. So...at worst I might need some new batts...but I don't have to run a slew of other tests. Thanks to all those who made suggestions and especially to Ejohnson, Titan Mike and Flybob who all told me to do exactly what cured the issue!
I love this place!!

[Murbella7]

Originally Posted by camaraderie

Well...I may have killed my batteries but I think I could have a different problem. Here's the story.
I store my RV in a storage lot where there is a single 120V/15amp plug. Once a month or so I run an electric cord to my converter DIRECTLY since it has a standard household plug and I charge up overnight.
Today when I arrived at the G'town...the stairs wouldn't go down. Yup...house batteries flat. Turns out that I left the salesman switch ON and drained them with both parasitic and normal losses since I had the overhead LED light on too. Mea Maxima Culpa!

I plugged into the 15a shore power driving my converter...but the stairs still did not go up.
Fortunately the engine battery started the coach and the stairs went up via alternator.

I'm seeing 13.7V from the ENGINE alternator at the battery terminals.
This allowed me to start the Onan generator.
With BOTH the ONAN and engine on I remained at 13.6 or 13.7V
Checking the output of the converter I also found 13.6V
When I turn off the engine but leave the genny on I see 13.6 at the converter output But only 12.8 at the batteries.

DITTO when I'm on shorepower.



So I have a good charging state when running off the alternator...but off of the genny or shorepower through the converter I am getting a significant voltage drop from the converter output to the batteries (13.6>>>12.8)
I was thinking bad ground... but there is no issue with the alternator charging circuit so I don't understand why a good converter output is not making it to the batts.
I've never looked inside the "battery center" box...could the issue be in there or something else? Or did I kill my batts and all will be well with new ones?

Thanks in advance for your help & thoughts.

I have flattened my pair of 120AH batteries and it took days to recover them with a 35 amp 7 stage charger. They are still good. The word here is that it will take more than a couple of hours for them fully charge and stabilise.

[TitanMike]

Originally Posted by Murbella7

I have flattened my pair of 120AH batteries and it took days to recover them with a 35 amp 7 stage charger. They are still good. The word here is that it will take more than a couple of hours for them fully charge and stabilise.

Even if you don't flatten your batteries it takes more than most people are willing to wait to bring them back up to 100%.

If you read the data on the more popular PD converters, their boost mode will restore most batteries to 90% in around 4 hours (depending on battery capacity and converter size). Next step can require a full day to a day and a half to finish the charge to 100% before the charger switches to storage mode.

If the charge cycle is stopped before the battery is truly charged 100% which is when as much of the sulfate formed on the plates has been converted to lead and sulfuric acid, your battery will continuously deteriorate. The sulfate formed during previous discharge cycles will become hard sulfate and no amount of boiling the battery with an equalization charger will change back.

Just going on manufacturer's claims alone, using something like the PD converter equipped with the charge wizard will close to double the battery's lifetime. Short cycling it can noticeably shorten the battery life.

[camaraderie]

Thanks guys...I have the 75 amp PD converter with Charge Wizard so I am getting a full charge in 48 hours I think! I'll disconnect everything for 24 hours in the AM and then measure voltage to see how much I damaged capacity. When we camp...we are always plugged in...so even if I knocked out chunk of capacity I'm hoping they will still be usable...but I've got a 20% off coupon at Track Auto I'm hanging on to just in case! Thanks again

[TitanMike]

Originally Posted by camaraderie

Thanks guys...I have the 75 amp PD converter with Charge Wizard so I am getting a full charge in 48 hours I think! I'll disconnect everything for 24 hours in the AM and then measure voltage to see how much I damaged capacity. When we camp...we are always plugged in...so even if I knocked out chunk of capacity I'm hoping they will still be usable...but I've got a 20% off coupon at Track Auto I'm hanging on to just in case! Thanks again

If you don't already have one get a battery hydrometer. One with thermometer so corrections in readings cam ne made based on electrolyte temp. It will give you a good indication of battery condition, in my opinion better than just voltage readings. A volt meter will show low state of charge but will it tell you if it's just low charge or dead cell?

[camaraderie]

Originally Posted by TitanMike

If you don't already have one get a battery hydrometer. One with thermometer so corrections in readings cam ne made based on electrolyte temp. It will give you a good indication of battery condition, in my opinion better than just voltage readings. A volt meter will show low state of charge but will it tell you if it's just low charge or dead cell?

Got one Mike but I only use it if I suspect a problem since the cells are such a PITA to reach.
Good news this morning is that everything is at 13.2 on the charger and droped to 12.8 after I disconnected the batts. So they have a little surface charge on them and I'll see how they settle out in the morning. If a cell was out , I'd see a big difference immediately so I'm gonna measure each batt individually tomorow and decide on how to proceed from there. Thanks again!

[TitanMike]

Originally Posted by camaraderie

Got one Mike but I only use it if I suspect a problem since the cells are such a PITA to reach.
Good news this morning is that everything is at 13.2 on the charger and droped to 12.8 after I disconnected the batts. So they have a little surface charge on them and I'll see how they settle out in the morning. If a cell was out , I'd see a big difference immediately so I'm gonna measure each batt individually tomorow and decide on how to proceed from there. Thanks again!

As how to proceed, I'd just keep charging away and keep using these batteries until they can't be charged anymore.

If you recharged them before hard sulfates were allowed to form on the plates you didn't loose much capacity. Might have taken a few months off the end of their life span but I wouldn't stay awake at night worrying.

Batteries eventually need to be replaced so just keep an eye on them and replace when they no longer meet your needs.

As for testing with the hydrometer, I just do it when I do my regular electrolyte level checks. I don't care for automatic water fill systems because they tend to let people put off the important checking of individual cells. Automation is nice but it can also trap you into believing all is well when it isn't.

[Preadus]

Originally Posted by camaraderie

Got one Mike but I only use it if I suspect a problem since the cells are such a PITA to reach.
Good news this morning is that everything is at 13.2 on the charger and droped to 12.8 after I disconnected the batts. So they have a little surface charge on them and I'll see how they settle out in the morning. If a cell was out , I'd see a big difference immediately so I'm gonna measure each batt individually tomorow and decide on how to proceed from there. Thanks again!

Camaraderie, I am having the same problem that you have described. I can't seem to get the coach charger to charge the batteries. In my case the generator doesnt seem to charge them either. Are you saying that you need to fully charge the batteries with an additional battery charger in order to get your converter to recognize and charge properly?

[camaraderie]

Originally Posted by Preadus

Camaraderie, I am having the same problem that you have described. I can't seem to get the coach charger to charge the batteries. In my case the generator doesnt seem to charge them either. Are you saying that you need to fully charge the batteries with an additional battery charger in order to get your converter to recognize and charge properly?

Well in my case, I first determined that my converter was operating at the right output...it was...but the reading at the batteries WHILE charging was 12.6 to 12.8 or so which meant I was not getting that 13.6 volt charge from the converter into the battery.
I started my motorhome and let it run using the alternator to charge and to test voltage again at the batteries and got about 13.6 at the batteries so I knew they COULD be charged...and the alternator is a dumb charger...just like a big bulk automotive shop charger.
So after running the engine for a couple of hours...I then plugged in the converter again and left for the evening and it was STILL reading around 12.8 on the converter when I left...but it came up to 13.6 the next day.
So my conclusion is that when a battery gets TOO discharged...the smart converter charger can't deal with it unless you first bring it up on a big conventional charger to a point where the converter can charge it properly.
And if you have a motorhome... the alternator will do the same thing.
Stand alone generators will not efficiently or effectively charge a battery by themselves.

Hope that helps you out. Happy to clarify anything if you have questions.

First step though is to make sure AT THE CONVERTER OUTPUT that it is putting out more than 13.2 Volts on your multimeter. Good luck!

[Preadus]

Seems a bit daft to have a battery charger that will only charge batteries when they are already charged. So what happens if you are out boondocking and they drain down overnight? You actually have to run the engine to get them charged enough to charge up. lol

[camaraderie]

Originally Posted by Preadus

Seems a bit daft to have a battery charger that will only charge batteries when they are already charged. So what happens if you are out boondocking and they drain down overnight? You actually have to run the engine to get them charged enough to charge up. lol

Yep,,, but we're talking about FLAT batteries...they should never happen on an RV unless you're an idiot like me! You should always start recharging at 50% charge and never ever let them get below 11.5 volts. All of the modern chargers will work that these levels.
But here's another way to rescue a flat battery to get it ready to be charged by a modern charger...Pretty creative!

https://www.youtube.com/watch?v=gMPuzmhYCQc

[rk06382]

Originally Posted by camaraderie

Well in my case, I first determined that my converter was operating at the right output...it was...but the reading at the batteries WHILE charging was 12.6 to 12.8 or so which meant I was not getting that 13.6 volt charge from the converter into the battery.
I started my motorhome and let it run using the alternator to charge and to test voltage again at the batteries and got about 13.6 at the batteries so I knew they COULD be charged...and the alternator is a dumb charger...just like a big bulk automotive shop charger.
So after running the engine for a couple of hours...I then plugged in the converter again and left for the evening and it was STILL reading around 12.8 on the converter when I left...but it came up to 13.6 the next day.
So my conclusion is that when a battery gets TOO discharged...the smart converter charger can't deal with it unless you first bring it up on a big conventional charger to a point where the converter can charge it properly.
And if you have a motorhome... the alternator will do the same thing.
Stand alone generators will not efficiently or effectively charge a battery by themselves.

Hope that helps you out. Happy to clarify anything if you have questions.

First step though is to make sure AT THE CONVERTER OUTPUT that it is putting out more than 13.2 Volts on your multimeter. Good luck!

Maybe the problem the line loss between the converter and the battery bank. The Converter on my FR3 has a 6 AWG wire that runs to the 12v DC fuse panel then to the Battery Control Center before it gets to the battery bank.

You could have a loose connector at anyone these locations.


ScottBrownstein has a thread on moving the converter closer to the batteries.
http://www.forestriverforums.com/for...ce-159791.html

[camaraderie]

Originally Posted by rk06382

Maybe the problem the line loss between the converter and the battery bank. The Converter on my FR3 has a 6 AWG wire that runs to the 12v DC fuse panel then to the Battery Control Center before it gets to the battery bank.

You could have a loose connector at anyone these locations.


ScottBrownstein has a thread on moving the converter closer to the batteries.
http://www.forestriverforums.com/for...ce-159791.html

Thanks Robert...but the problem has been resolved as due to flat batteries which prevented the converter from "seeing" the battery. Once batts were charged up by the alternator....the converter worked correctly.
There is no longer any significant loss in the path from converter to battery.

[rk06382]

Originally Posted by camaraderie

Thanks Robert...but the problem has been resolved as due to flat batteries which prevented the converter from "seeing" the battery. Once batts were charged up by the alternator....the converter worked correctly.
There is no longer any significant loss in the path from converter to battery.

Your right if it ain't broke don't fix it. The think what I get out of this is the converter will maintain the batteries but not recover from a flat-line.

[Murbella7]

Originally Posted by TitanMike

Even if you don't flatten your batteries it takes more than most people are willing to wait to bring them back up to 100%.

If you read the data on the more popular PD converters, their boost mode will restore most batteries to 90% in around 4 hours (depending on battery capacity and converter size). Next step can require a full day to a day and a half to finish the charge to 100% before the charger switches to storage mode.

If the charge cycle is stopped before the battery is truly charged 100% which is when as much of the sulfate formed on the plates has been converted to lead and sulfuric acid, your battery will continuously deteriorate. The sulfate formed during previous discharge cycles will become hard sulfate and no amount of boiling the battery with an equalization charger will change back.

Just going on manufacturer's claims alone, using something like the PD converter equipped with the charge wizard will close to double the battery's lifetime. Short cycling it can noticeably shorten the battery life.

I was devastated by my mistake in causing the load to remain that flattened the batteries. I was therefore more than happy to wait as long as it would take to recover them. The alternative was facing the wrath of the DW over having to spend another $800 to replace the batteries. The amazing thing is that despite everything I had read about how such a state could never be reversed, I persevered and won, which was my reward for paying so much money for such a great battery. Which btw, I needed in order to replace a really cheap and nasty bit of rubbish (a single too) supplied by the dealer that would only retain a charge for a 5-8 days if not constantly on float.

[ejohnson1144]

Thumbs up

[camaraderie]

Just a (hopefully) final update for all those who chipped in with good advise...
After fully charging the batteries...I disconnected the negative and let them sit for 5 days and just re-measured the voltage after sitting and settling and the batts are at 12.7...100% full in static measurement.
I may have some loss of capacity from the single flattening...but it is certainly not anything to worry about.
Thanks again to all.

[MNtraveler]

Originally Posted by camaraderie

Yep,,, but we're talking about FLAT batteries...they should never happen on an RV unless you're an idiot like me! You should always start recharging at 50% charge and never ever let them get below 11.5 volts. All of the modern chargers will work that these levels.
But here's another way to rescue a flat battery to get it ready to be charged by a modern charger...Pretty creative!

Also they WERE being charged. Which is proven by the fact that they DID charge up.

[MNtraveler]

Originally Posted by camaraderie

Just a (hopefully) final update for all those who chipped in with good advise...
After fully charging the batteries...I disconnected the negative and let them sit for 5 days and just re-measured the voltage after sitting and settling and the batts are at 12.7...100% full in static measurement.
I may have some loss of capacity from the single flattening...but it is certainly not anything to worry about.
Thanks again to all.

You did a good job diagnosing and handling this - well above average for what we see posted typically. And I don't mean that in a condescending way - I mean it.

Now just one thing to save you some effort. You can skip that needlessly complicated practice of plugging the converter into an extension cord and then to a wall outlet. You can plug the RV power line straight into the wall outlet using a small 30A to 15A adapter and the converter will work just fine. It draws <10A and after a while only draws 1A steady state. And you can leave it on nonstop since it has a periodic anti-sulfation (boost) cycle. Just be sure to leave the battery switch on!

Adapter:
Camco Heavy Duty RV Auto PowerGrip Adapter- Contoured Shape For Easy Grip and Removal (15M, 30 Amp, 125 V, 1875 W) (55223) https://www.amazon.com/dp/B00192JGA8/ref=cm_sw_r_cp_api_XJtjBbYMKRPKB

I am assuming you have a good Progressive Dynamics converter (they call the good ones Power Control Centers now), and if so, you can get the manual here: https://www.progressivedyn.com/rv/power-centers/inteli-power-4000-series/ Or https://www.progressivedyn.com/service/discontinued-product-resources/owners-manuals/

If not, you should check your unit's manual to verify it will go into trickle charge or float mode.

[WolfWhistle]

camaradarie, interesting thread! The initial concern was the 5% voltage drop from charger to batteries. That 13.6 to 12.8 volt drop is a bit high, but not surprising. What you went through shows the difficulty in going by volts only. Volts and current and resistance all factor in.

But, you know quite a bit about these chemical storage things. Knew to rest them before reading, etc. Believe me when I say, I am not picking and am first to admit I am learning as I go.

Back to the issue, the sure way to know state of charge is SG. So, going back to the puzzling voltage drop... 75 amps of current, since we know the batteries were very low that charger was grunting (sorry to be so techincal LOL)... so with 4AWG wire (dunno, just guessing) and 19 feet (another hypothetical) the drop is indeed 5.21%. If the CC can make more amps than that it is easier to justify that 5% scenario.

What you need... we all need... is a good SOC true battery monitor. Victron makes a cool one that is bluetooth to a smartphone app, and there's the old standby Trimetric TM-2030. Amps, Amp/hr, W/hr its all there. Those plus a shunt and some wiring is all it takes.

I'll bet money there is nothing wrong with your Progressive charger even it is made for folks that nearly always stay plugged or go from from full-hookup to another... no reason to think an automotive charger was any better. The Progressive just needed time and you let it takes its time.

The alternator helps, but with your high cranking amp battery and the deep cycles, at the same time... the alternator's goal isn't getting those deep cycles charged properly. Plus the length of the run and gauge of cable... sounds like it was shorter than the CC to battery run.
WW