Exactly! I had intended to go to a local campground to charge the dead batteries. But i know now that would not have charged the batteries. It would have provided power to all equipment, but that's it.
OK, everyone, I merged the original thread in the Charleston sub-forum with a duplicate thread in the Georgetown sub-forum, so if you see that you posted the same info to both, don't worry about it.
To get maximum eyes on the issue, I moved the entire discussion to the Technical Forum for Electrical and Charging systems (where it probably belonged in the first place). If anyone needs to have a post edited or removed as a result of the merger, please PM me and I will take care of it. Herk
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
I am so happy that there was a "happy ending" to your story.
Do you know if he load tested the batteries or just did a visual inspection?
Did he say why your BCC was not charging the house batteries with the engine running?
BCC? First was a visual then tested to find voltage which was 5 volts so he hooked up a battery charger to get a sufficient charge to get the connect switch to light up and then started the generator to finish of the charge.
He said a dead battery cannot charged using just the engine running. Or without the connect switch activated. Trying to use the battery boost was also an exercise in futility.
PMSHERMAN gave you the straight scoop. The BCC works like he said. If you don't leave the coach plugged in to shore power or supply a trickle charger to the batteries, they will go down again if they are connected to the cabling. The disconnect switch does not remove all parasitical current draw. Powered step controller and gas detector (and possible other items) remain powered even with the switch off. Even with that small current consumption the batteries will still deplete over a month to a level where the BCC will not be able to trip the solenoid that to put the AC/DC converter back on line and the level will also be too low to start the generator. You can extend that time period by installing a knife blade switch on the battery to disconnect everything from the battery. If you have two batteries, then you will need to add two knife blade switches to ensure that the batteries are disconnected from each other.
BCC? First was a visual then tested to find voltage which was 5 volts so he hooked up a battery charger to get a sufficient charge to get the connect switch to light up and then started the generator to finish of the charge.
The Georgetown's Battery Connect Center (BCC) manages the batteries by directing the charging current from a variety of sources (engine alternator, generator inverter, House converter) to keep your batteries charged.
Here is the schematic and there are some "fuses" in it that can fail to prevent the alternator from charging the batteries. These need to be checked to find out why the engine was not charging your batteries.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
PMSHERMAN gave you the straight scoop. The BCC works like he said. If you don't leave the coach plugged in to shore power or supply a trickle charger to the batteries, they will go down again if they are connected to the cabling. The disconnect switch does not remove all parasitical current draw. Powered step controller and gas detector (and possible other items) remain powered even with the switch off. Even with that small current consumption the batteries will still deplete over a month to a level where the BCC will not be able to trip the solenoid that to put the AC/DC converter back on line and the level will also be too low to start the generator. You can extend that time period by installing a knife blade switch on the battery to disconnect everything from the battery. If you have two batteries, then you will need to add two knife blade switches to ensure that the batteries are disconnected from each other.
1--I don't know what BCC is.
2--I don't have the luxury of leaving the coach plugged into shore power, or an electrical hookup to run a trickle charger My MH sits in storage with no electrical hookup.
3-- I do know to disconnect the coach batteries when in storage. What i didn't know until the last couple days was there was still some major decay of the charge even with the disconnect activated.
4-- i found out today that a fully discharged battery cannot be charged using the engine alternator or any other charger not directly hooked up to the coach batteries. Also, the converter will not charge a fully discharged coach battery either until the connect switch can be turned on-same as running the generator which can't be done until the connect switch can be activated. Without an electrical hookup, the only way to charge the coach batteries to the extent that the connect switch can be activated is by using jumper cables from a running engine's battery directly to the coach batteries to get charged enough to activate the connect switch to then run the generator. This all learned from an an qualified rv repair technician who explained the whole process to me.
Quote:
Originally Posted by Schvarak
I was lucky, the batteries weren't terminally dead. Will be running the generator in storage at least once per month as well as topping off distilled water at the same time. That should keep the batteries healthy for a while.
Before we make all kinds of generalizations, his problem was unique. The battery disconnect was fired (batteries off) and the house was stone, cold dead. Like 5 volt dead! This means that the batteries could not be re-connected since the power for that comes only from the battery bank.
As such nothing could charge the batteries...before they were charged a little to enable the disconnect to fire...not fully charged, mind you, but maybe 11 volts!!!
If the main switch was still on, the alternator would have charged the house, the boost switch would have jump started the generator and the converter would have charged both house and chassis banks.
Consider that that your batteries may no longer hold a charge. If they sulfated badly while totally discharged they may reach full charge but without adequate reserve capacity sometimes called a "surface" charge. If so the batteries will quickly reach an apparently full charge voltage but will discharge very rapidly. I wasted several days last summer trying to recover two house batteries that had been totally discharged for several months. Wound up replacing both. Did your service guy load test the batteries when he said they looked alright? You can't be sure just by reading voltage with a meter. You will find out in just a few days if they can't hold a full charge. If you have your own tester, read your voltage with no 12v systems on and no shore power on. Then turn on all your 12v lights for 10 or 15 minutes and check voltage again. If it drops substantially your batteries likely won't hold a full charge. If they hold a decent charge, about 12.7v or more they should be fine. If he load tested them they should be fine also.
Before we make all kinds of generalizations, his problem was unique. The battery disconnect was fired (batteries off) and the house was stone, cold dead. Like 5 volt dead! This means that the batteries could not be re-connected since the power for that comes only from the battery bank.
As such nothing could charge the batteries...before they were charged a little to enable the disconnect to fire...not fully charged, mind you, but maybe 11 volts!!!
If the main switch was still on, the alternator would have charged the house, the boost switch would have jump started the generator and the converter would have charged both house and chassis banks.
Something to remember for all of us.
Scott, when you say the main switch, are you talking about the connect/disconnect switch on the panel just inside the door?
The next paragraph is basically exactly what the repair guy said "lacking any power in the storage lot, jumping from the chassis battery directly to the house/coach batteries is the only way to charge them sufficiently to fire? the connect switch to enable further charging of the batteries. Without the connect switch on, there is no way to charge them using any strategy to charge. That's why the alternator/ battery boost attempts to get the generator to start were ineffective.
In regard to Bill's suspicion that the batteries may not hold a charge, I'm trying to contact the repair guy to get answer's to the load test etc questions. Thanks again for your advice!
Yep...the one by the door. It uses a Trombetta switch that is powered to connect and then powered to disconnect. In either state it doesn't use any power. You hit a really interesting dilemma. Can't connect with totally dead batteries. I was worried that if your batteries were that low they may be permanently damaged, but time will tell.
Consider that that your batteries may no longer hold a charge. If they sulfated badly while totally discharged they may reach full charge but without adequate reserve capacity sometimes called a "surface" charge. If so the batteries will quickly reach an apparently full charge voltage but will discharge very rapidly. I wasted several days last summer trying to recover two house batteries that had been totally discharged for several months. Wound up replacing both. Did your service guy load test the batteries when he said they looked alright? You can't be sure just by reading voltage with a meter. You will find out in just a few days if they can't hold a full charge. If you have your own tester, read your voltage with no 12v systems on and no shore power on. Then turn on all your 12v lights for 10 or 15 minutes and check voltage again. If it drops substantially your batteries likely won't hold a full charge. If they hold a decent charge, about 12.7v or more they should be fine. If he load tested them they should be fine also.
Almost 48 hours since charge. Unfortunately, i don't have the voltage after charging. But, today's voltage is 11.9. Turned on all the 12V and now waiting for the 10-15 mins. Will charge again before i leave, just to get correct current voltage.
Quote:
Originally Posted by ScottBrownstein
Yep...the one by the door. It uses a Trombetta switch that is powered to connect and then powered to disconnect. In either state it doesn't use any power. You hit a really interesting dilemma. Can't connect with totally dead batteries. I was worried that if your batteries were that low they may be permanently damaged, but time will tell.
11.9 is only about 40%. How long did you originally charge? It can take almost 48 hours or more to get to 100% with any converter.
About 1.5 hrs with both generator and alternatorrunning.
Finished 15 minute of 12v equipment turned on, voltage drop of around .4v Thinking about taking home and using my charger rather than all this gasoline. ☺ What would a normal fully charged voltage be? Like I said before, I don't know what the voltage when stopped charging Thursday.
13.25 is the float voltage of the converter. In other words, it thinks the bank is fully charged and has dropped down to trickle. If your batteries have been damaged, they won't take a lot of charge current to get up to "full charge", but they also won't supply a lot of current before they drop to an uncharged state. You were at 40%, normally it would a long while to get back to 100% on a reasonable converter. Unfortunately I think your problem may have killed your batteries. See the attached curves from Progressive Dynamics. Even at boost, it takes at least 12 hours to get to 100% from 40%.
13.25 is the float voltage of the converter. In other words, it thinks the bank is fully charged and has dropped down to trickle. If your batteries have been damaged, they won't take a lot of charge current to get up to "full charge", but they also won't supply a lot of current before they drop to an uncharged state. You were at 40%, normally it would a long while to get back to 100% on a reasonable converter. Unfortunately I think your problem may have killed your batteries. See the attached curves from Progressive Dynamics. Even at boost, it takes at least 12 hours to get to 100% from 40%.
Ok, took one final test 13.2V
Shut down gen and disconnected batteries. 12.45V now.
The biggest load on 12 volt that you certainly have is your furnace blower (unless you have a residential reefer and an inverter.) Turn on the furnace and I bet the voltage will drop down below 12 pretty quickly. If so, you batteries are toast. Based on the speed that you are charging at, I bet it is so.
Linear Mode
