Generator start battery

[jelmore]

I replaced the generator start battery 4 months ago and have used it maybe a dozen or so times with no issues. While waiting for a replacement fan for an inverter, and while plugged in to shore power, I turned off that inverter, one of two, to avoid the noisy fan. The other inverter seemed to keep the house batteries charged. Just in case the house batteries did not stay charged, I kept the generator autostart system on.

After about a week in this state, all the generator lights inside started flashing. The only way to disable that was to unplug the Watchdog module. While checking things, I noticed that the generator start battery charge showed 10V!! Those flashing lights must indicate a low voltage situation.

A paragraph of questions: How did this happen? Could it be that Inverter #1 keeps that battery charged and by having that inverter off the battery drained? What kind of load is on that battery that would cause that much discharge? The Watchdog system? Does that battery even get charged other than by the generator? Could it just be a bad battery?

That battery is a critical link to this entire system. As far as I know, there is no other way to start the generator. I've read about emergency links to other batteries in some installations, but I'm pretty sure my coach doesn't have anything like this.

Perhaps this is something I need to take up with Liberty. Thought I should check here first.

[truk4u]

Jim,

You need Jon to jump in here since it's a Liberty. Harry had the same issue in Branson with respect to the gen battery. You said you shut down the noisy inverter and the other kept the house batteries charged. I think you will find that both inverters are needed for the charging cycle, each charging certain batteries. Your Liberty is setup to charge the gen battery via one of the inverters, so possibly your noisy shut down inverter was the one that should have charged the gen battery.

[jelmore]

If that's the case, one inverter keeps the generator battery charged, it sure makes me wonder what kind of load was on that battery to suck all the juice out of it. It wasn't used at all. And now that both inverters are back on line, the battery isn't charging.

[Jon Wehrenberg]

I can't help on this one. It is possible the battery is bad.

If it turns out the battery tests bad, a new one should show 14 volts on the generator voltage gauge with the inverters on because the generator battery charge is maintained that way. If not there is a problem in the circuit from the house batteries to the genaerator battery, possibly the isolator that should be located in the electrical compartment if it is like my Liberty.

[jelmore]

Talked to Tony in Chicago on this one. In this coach, there is no connection between the generator start battery and the house batteries or the inverters. The Watchdog monitoring system is powered by the house batteries and there are no loads on the start battery other than starting the generator. That battery is only charged when either the engine or the generator is running, not by shore power or the inverters.

Seems I have a failed battery.

[Jon Wehrenberg]

Good to know. That is 100% different from mine. We have been sitting in Spearfish for 4 or 5 days and the generator battery voltage is showing 14+ indicating our battery is having its charge maintained by the inverters. If that was not the case we would be showing around 12.7 volts.

[jelmore]

I asked Tony if there was a trickle charge circuit -- not knowing what I'm talking about -- on the inverters that could be sent to the start battery and he said no.

I'm sure your Elegant Lady would be more sophisticated than my Classic. But I can't imagine why they wouldn't provide a charge for the generator start battery from shore power on this coach. Seems it would be a simple thing for them to do.

Off to the battery store.

I'm running the engine now and the battery voltage still shows 10V. Would that for sure indicate a bad battery, or perhaps a malfunction somewhere between the alternator and the generator start battery?

[Kenneth Brewer]

I agree; that is interesting, particularly since we have 2000 Liberty as well. I will check the battery under shore power to see if it is being charged, as Jon suggests. I was the impression somehow that the inverter battery charger, one or the other of the two, if not both, had the generator as one of the loads. I imagine you have a number of POGGers scrambling to confirm their systems now. Thanks.

[Ray Davis]

That battery is only charged when either the engine or the generator is running, not by shore power or the inverters.

In my '93 Country Coach I was told that the generator battery was only changed by the GENERATOR, not the engine, and that if you didn't run the generator periodically, this battery would die.

I don't know if that really is true. About 6 months after getting that coach, I had to replace the generator battery. It was still working 6 months later, however I did try to run the generator once a month.


Ray

[hhoppe]

Jim: I did have the same problem while in kerrville. The remedy was to replace a 12V SHOTTKY ISOLATOR Model 52-75 / VANNER Battery Isolator that is between the gen. battery and its power source from the clear plastic covered electrical panel in the same bay. My 2000 Liberty coach is a 12V coach. That item solved my problem. about $60.00 as I remember. Vanner is in Hilliard, Ohio according to the label. I had the same symptons and it fixed it.
It's about 3" X 5" black finned box. Good Luck.
You can call me @ 530-277-5534
, I'm in Spearfish with the POGGERS.

[jelmore]

Thanks Harry. I'll bet that's what the problem is.

I asked Vanner how to test the isolator. I told them what Liberty told me, that the battery is charged from the alternator. They said to check voltage on the battery side and compare to the other side when the engine is running to see if alternator current is passing through. There should be a -.4V to -.7V or so difference.

I checked it with the engine NOT running and surprise, surprise ... battery side was 10V and the other side was 13.5V. Checked the 12V alternator and it reads 13.5V. I know the 12V alternator charges the house batteries, and the house batteries are at 13.5V, so there must be a connection to the house batteries through the alternator, and the isolator must be an isolation between the house batteries and the generator battery.

If the isolator was working, I would think there would be a similar voltage on both posts. The isolator failure must have happened months ago and that caused the new generator battery to get used up. Since it is at 10V, I'd guess it's all used up and wouldn't take a charge if the isolator is replaced.

Does any of this make sense or am I imagining things?

[Jon Wehrenberg]

Jim,

The Liberty response to you troubled me until I got home and read this thread again.

I stand by my original response.

All charging sources on our buses also charge the generator battery. Inverters, generator alternator and engine driven alternator as is the case on my coach as well as yours.

[jelmore]

Just before I ordered a new isolator, I called Tony back to run my voltage readings by him. Then, he said he didn't really know how it was set up, that this topic was really Bill's department.

So, lots of discovery on my part. Thanks for all your experience. I think I'm starting to get some of this 12V business.

[Jon Wehrenberg]

Jim,

No disrespect meant to owners, but one thing is for sure. Advice specific to a particular converter, and specific to a particular model from the converter needs to come from either the converter or someone knowledgeable about your specific converter and coach model.

The so called mystery of our 12, 24 and 120 volt systems is not that difficult to understand, especially when we learn how to monitor our systems and we get to develop an understanding of what our coach gauges and displays are telling us.

When your repair is made, monitor your generator voltage gauge under various conditions such as alternator running via the generator motor, via the bus motor running, via the inverters charging the house (such as when on shore power) and with nothing running and the bus not connected. I am sure you will quickly learn exactly what maintains a charge on your generator battery. From that point, isolating the problem is simple. (Not intended to be a play on words)

[jelmore]

Well, little did I know that the information I got from Liberty Coach was wrong. How in the world would I know? If not for this forum, I would have been replacing generator start batteries every 4 months. Thanks to all. When I get the new isolator in, I'll hope I'll be able to confirm that all is well as it was on Harry's coach.

[Jon Wehrenberg]

Jim,

All that isolator is intended to do is to pass the charging current through to the generator battery, but not to allow current from the generator battery to flow back to batteries with lower voltage, such as house batteries that may need a charge. That way the battery will have starting voltage when you need to start the generator to recharge the house batteries.

I have never followed the wiring backwards so I do not know the specific origin of the incoming charging voltage sources. They may come to a common point or they may be a single source such as house batteries which are charged via the bus alternator and the inverters, and thus are both capable of charging the generator battery.

The isolator may be checked for continuity via an ohmeter which should show current can flow in one direction and not the other, and then a voltmeter to show current on the input side is in fact flowing through to the battery side.

I will stick my neck out a mile here and predict you may find the generator alternator is not putting out charging current because I cannot imagine that the alternator output will be fed into the input side of the isolator and thus back to the house batteries. Let me know. I will have egg on my face if I am wrong, but I am curious.

[dalej]

you may find the generator alternator is not putting out charging current_Jon

Why would a coach set up this way have a generator alternator? I don't have one and it makes sense. Your house batteries and generator battery (I have one) are charging going down the road or while parked and plugged in or the generater is running and the inverter is charging them.

[Ray Davis]

******Status, In the barn. Last trip 9.11-17.09 POG

Hey Dale, that was a long trip! 8 months? What month is the 17th month anyways? :D

Ray

[dalej]

Sorry, I thought it looked like Sept. 11-17 of 09

[Ray Davis]

Sorry, my bad. I mis-read it!! :eek:

[Jon Wehrenberg]

Dale,

Good question and a correct observation. On my original coach the alternator belt was just removed. On my current coach the belt is in place and that just might be to run the water pump. I have never checked to see if it is generating current.

[Joe Cannarozzi]

Why would you want to eleminate another perfectly good way, in that gen alternater, to charge batterys?

If we throw the 12 volt equalizer switch it not only allows us to jump start the gen from the house but it also allows us to charge the gen off the inverter/charger and we can also charge the house off the gen alternater if the inverter/charger fails.

So let me see if I have this right. I need to remove a perfectly good alt and another charging source and oh ya, ADD a completly unnessessary turbo to my generator:confused:

Good Golly

[jelmore]

You guys are a riot!

[Joe Cannarozzi]

Jim this is way better than you could ever imagine.

[Jon Wehrenberg]

Jim,

Step back a little while I try to adjust Joe's attitude.

Joe.....you are thinking like a guy with a Winnebago. If the generator battery wasn't keeping its charge maintained via the inverters or the bus engine driven alternator then using the generator alternator makes sense, and in fact it may be getting its charge from the alternator now, only I have not bothered to check.

When our fancy schmancy Liberty buses are running all batteries including the generator battery are getting a charge. When our bus is connected to shore power the battery is getting a charge via the inverters, and when the generator is running the battery is getting a charge via the inverters. I suppose we could shift into overkill and run the generator alternator also (if it is not already) and add another charging source. Or do you think the national electric grid powering two inverters, or 470 HP driving an alternator will be enough or a generator powering two inverter/chargers is enough?.

There is no way a 30 or 45 amp alternator on the generator is going to be able to backfeed and contribute to a charge on the house or chassis batteries. They have the potential to suck the electric right out of that tiny alternator and make it run at full capacity 100% of the time the generator is running making its lifespan about equal to the attention span of a member of congress,.

[jelmore]

Well, the humor of it is starting to set in.

I just got my new isolator. One side is labeled +12V and the other side is labeled Load. And, it's labled "Medical Equipment". Any idea how this should be connected? Maybe this is Jon's ohm meter thing he mentioned, though I'm clueless. May have to wait until Monday to check with Vanner.

[Kenneth Brewer]

Well, the humor of it is starting to set in.

I just got my new isolator. One side is labeled +12V and the other side is labeled Load. And, it's labled "Medical Equipment". Any idea how this should be connected? Maybe this is Jon's ohm meter thing he mentioned, though I'm clueless. May have to wait until Monday to check with Vanner.

'Load' terminals are wired to generator battery, if we are talking about the isolator for the genset. The load is the gen battery, which is isolated if the source (12V) voltage is less than the generator battery. That is how ther terminology is adopted in industrial cases (UPS, standby generators). Having said that, it IS possible the terminology for vehicles/vehicle systems is used 'backwards', but I doubt it. We don't want to get into what the '+' really means on batteries - "holes" vs. electrons, and start a fight between electrical engineers and battery makers. Oh, ....just skip it.

[Joe Cannarozzi]

Shoot Jon I gave up eons ago trying to be one of the big dogs.

You can give a guy a prevo but you can never erase the memories of that Coachman.

Maybe someday I too will have a turbocharged gen. (without an alternator):o

[truk4u]

Country Coaches simple system sure looks good now. Stand alone battery for the gen, charged only by the gen. If the gen battery gets discharged, you push the boost switch tying in the house battery bank.

K I S S

[tdelorme]

Country Coaches simple system sure looks good now. Stand alone battery for the gen, charged only by the gen. If the gen battery gets discharged, you push the boost switch tying in the house battery bank.

K I S S


K I S S ?? Is that an acronym for I have to go outside in the rain, sleet and snow to pull a little handle so the sewer tank will dump after which I have to continue to stand out in said rain, sleet and snow in order to pull another little handle so that the gray water will dump and hopefully clean most of the poop out of the sewer hose all the while wondering how the hell Jimmy C. ended up with a Liberty and I'm left with a bus that causes me to go out in the rain, sleet and snow just so I can use the K I S S acronym?
:p:p

[Joe Cannarozzi]

Oh no Tom, not near complicated enough for the big stainless bus.

[Jon Wehrenberg]

I believe Ken has it right. Rather than make it complicated just hook it up the way the old one was. K I S S.

Tom is clearly exhibiting a little envy. And Mel nailed him. I love it.

[truk4u]

Yes Mel, just set inside and wait for your auto poop extractor to quit working, then you can go out in the rain and spend the next 2 days trying to figure out how to relieve the Bling Mobile of mass quantities of Jdub's favorite liquid!:D

Pulling those levers (that always work if maintained) is such a degrading, time consuming, difficult process that taxes the muscles in your arms and back!:p

[jelmore]

All done here. You all go ahead and chat.

With the new isolator in, batteries and inverters on, shore power off, +12V side reads 12.6V and the generator battery side reads 12.3V. Vanner says they expect a .5V drop.

With shore power on and the chargers at the beginning of their cycle, the +12V side reads 14.2V and the other side is 13.9V.

Jon, like you said, all the power sources are connected on a Liberty.

Excellent. Thanks all. (Harry, glad this happened to you!)

[hhoppe]

Jim; When I returned from the POG rally in Spearfish we spent a night in Sparks Marina RV park in Reno. They were having a Bus and Bikers rally there. The big Liberty semi truck and Troy Moody and some other Liberty techs. were there. Upon inspection of my bus they saw I had put a battery switch ahead of my generator battery. I explained I did not want the " Watchdog " system starting my generator while the bus was in indoor storage. They said I could unplug the group of wires below the watchdog control box while in storage. That allows the generator battery to be charged while in storage along with the other house batteries. They had a Solenoid Water Valve on hand to make a replcement I needed and helped with some other items needing repair. I told them we better see that big repair truck and crew at our Oklahoma Rally next October. Us Liberty owners need to keep the pressure on them to do it. Skiff and Jon are you reading this. The Bus n Bikers group had quite a few newer busses. They looked like the high money boys with new toys. Glad you got your problem solved.

[Jon Wehrenberg]

Harry,

While it is nice to have the repair truck, I am of the opinion that teaching the owners how to operate their Liberty would be significantly more important. I feel strongly that most owners do not know the operation of a lot of their systems, and as such often do not even know when something is wrong.

Before anyone can request service, they first have to know they have a problem and a lack of understanding of the coach often prevents that.

[jelmore]

Yep, unplug the Watchdog and all is manual, yet everything charges just fine. Our is working as it should on autostart and not. Or, just turn off the Auto Start in the electrical panel if you don't want it to automatically start.

Now, I just noticed another issue. I've got a call in to Tony at Liberty awaiting his response. I started the generator while dry camping and noticed that the house batteries, at the beginning of the inverter/charger cycle were NOT charging the house batteries at 14.5 volts as they should. I talked to Lifeline Batteries and they said that as soon as AC is supplied to the inverters, either as shore power or generator power, the normal 14.5 volts should show up for the first hour of charging (Freedom Combi 25 inverters). That is NOT happening, so I suspect a transfer switch failure. What I see with the generator running would be more like a smaller alternator charge. I don't really get it . . . yet.

Is this related? . . . a few moths ago, I started the generator while plugged into shore power (probably should not?). Everything seemed fine until I unplugged the shore power cord. It was an extension cord, not the cord reel. One of the plug prongs was fried. It didn't short and trip a breaker, it just burned and kind of melted. Maybe a transfer switch problem? I don't know, but I'm working on it.

I'll start a new thread when I learn something, for posterity.

[garyde]

Hi Harry. Did Liberty solve your inverter problem, or was it your alternator?
Also, did you find the controller for your bedroom blinds and have
you learned why they all 3 blew fuses at the same time?
Hi Jim. If you plug in a 30 amp cord or less to shore power, you have to turn off Inverter # 1 in your coach and monitor your loads to keep them below your cord size or c ircuit size at shore power.
Also, if you have new batteries, did the people who installed them check your inverter's charge settings? You may be on the wrong setting.

[jelmore]

Gary, that was a 50 amp cord. And, I'm the one in charge of those inverter settings! I'll reread the instructions and check them again. But it seems if the generator is supplying house power, then that power should also be running the chargers just as if the bus was on shore power. But, I don't know how Liberty has those things connected. I won't speculate.

[jelmore]

Hi Harry. Did Liberty solve your inverter problem, or was it your alternator?
Also, did you find the controller for your bedroom blinds and have
you learned why they all 3 blew fuses at the same time?

Harry -- I've been all through my blinds and know them well now, and the people that made them for Liberty. If you have any questions, I might have answers. If you have other solutions, let me know! Thanks.

[Jon Wehrenberg]

The Liberty transfer switch if working properly prioritizes power source.

If it does not sense shore power or the generator output it defaults to inverters, and only the 120V circuits powered by the inverters such as TV, Refrig, forward and rear outlets, microwave, and water pump will have pwer to them.

When connected to shore power the transfer switch makes that power available to all circuits in the 120V panel and the inverters are fed 120V power and instead of providing power to the panel they function as chargers and they pass the shore power through their own internal transfer switch to the previously mentioned circuits.

If the transfer switch detects the generator running (output from the generator) it disconnects from shore power and instead transfers generator power.

With everything working correctly in the transfer switch no two power sources can ever provide power simultaneously, nor can they back feed. If the prongs on the power cord were burned my first guess will be there was corrosion on the prongs or in the shore power receptacle which created resistance and in turn created the heat to burn them. It had nothing to do with the generator being run, but more likely was due to a large current draw such as 40 amps or more prior to or after the generator was run.

As to the charging issue with the house batteries, my first place to look for why charging did not occur would be with the inverters. I doubt they both failed simultaneously or suddenly started working again, so I would look at switch positions and verify that 120 Volts was reaching the AC panel. More information is needed. BTW, the appearance of charging voltage is not necessarily time related unless the inverters are set up to go into equalize mode every time they are powered up. That is an 8 hour time and should only be done when required. All other charging is at the 14.2 to 14.4 rate for bulk and absorbtion, and then a lower voltage for float. The times within those three phases is based solely on the battery state of charge.

[jelmore]

With either shore power or generator power, all AC circuits are powered. Unless there is a converter present, and correct me if I'm wrong, the batteries continue to power the DC loads.

The way I understand the Freedom chargers, each time AC becomes available, they start the charging cycle at the bulk rate. And I'm not seeing 14+ volts when the generator starts, though the batteries do seem to charge. If I turn of the charger circuit breakers, the amp load drops.

When I get to shore power next, later today, maybe I'll get a chance to confirm what I'm remembering.

[Jon Wehrenberg]

Jim,

There is a delay timer in the transfer switch. Also remember if the batteries are down on power, it will take the chargers a period of time to ramp up to the bulk rate voltage and power. If you have your inverters set for the lowest charge amperage for power managment at campgrounds with minimal power it will also take a while before you see that voltage.

It sounds like everything is OK.

The load dropping when the chargers are turned off indicates to me that they are functioning.

[Jim Skiff]

Jon has updated his electrical article with pictures. (http://www.prevostownersgroup.com/public/index.cfm?fuseaction=articles.view&id=5765&publicationtype=Articles)