12v system dead or near dead

So my RV has been sitting for a couple of weeks, plugged into shore power. This is on my farm. The 110 system is working fine, the internal surge protector seems to be fine, the monitor on it shows no errors.

So suddenly all 12 V systems are not working. Led Lights won't come on, intellitec out, etc, perhaps tellingly the very lowest draw light on the whole system is on, It's a little indicator light.

The rocker switch on the dash that cuts off all 12 V is in the on position.

both coach batteries and chassis battery only have 3 V.  So far have not found any bad fuses. The converter is only putting out 3 V.

This is the progressive dynamics model PD9260c.

Do I have a bad converter charger? Should I be looking for another problem? 

Right now I have the regular automotive charger on the chassis battery.

I forgot to include that the dash lights are not coming on, no headlights, won't start obviously.

You did not mention the make/model of the RV* but many do not charge the chassis battery when plugged in and that might explain at least that one and all the chassis related items: dash lights, headlights, etc.

There are 3 fuses on the 9260c itself, two may be for the reverse battery protection system which would prevent the charging function for taking place. The 3 volt output you found may be the battery itself if they are still connected and not the output of the converter. But there are a few parasitic loads that can kill the batteries if they are not being charged. (ie, the propane detector)

Do you have 120V at the converter input??  Circuit breaker for the converter ok?

PD make a superior product but that is not to say they cannot go bad...

* Suggestion: look under Profile on the menu above and add pertinent info under Signature similar to that you will see in many other signatures.

This is a 1999 Itasca Suncruiser 37G, older class A.

The problem with the coach batteries (2 6 volt golf cart batteries in series, about two years old) was that the water was low and they weren't holding a charge. I filled the water and they are charging now, all 12 volt systems woke up.  Hopefully i have not ruined them.

I also Charged the chassis battery and the vehicle starts now.  It's harder for me to figure this one out. It's manufacturing date is 5/14, perhaps it is simply failing.

I will pull the converter out tomorrow and look at the fuses, I installed it about 1.5 years ago

There is a good chance that one or both batteries were fried by going dry.  The big questions is what caused them to go dry.  If all the water was boiled out in a short time your charger might be bad.  If you're going to leave it plugged in for extended periods you might want to look for an intelligent charger that does float or maintenance charging.  If your charger will accept a 'Charge Wizard' that would be a good idea.

Well they were not completely dry. The water was to the top of the plates. This is the first time I put water in them, my bad. I'm pretty sure the charger I have qualifies as a smart charger.  I did not have time to look at it today, will have to do so some other time

Sorry, I mis-read your original post.

So this problem turned out to be simultaneous failure of all three batteries.  The chassis battery aged out. Both house batteries failed as well, a bit prematurely due to me forgetting to check the water.

If the low water was over the plates in the batteries, they will still be usable.  The won't hold a charge for as long as they used to because they were so far discharged.  They probably should be replaced before too long, depending on your needs.  If you always stay in places with hookups the batteries will probably be OK for a year or maybe several. 

If the water was down far enough that the plates were exposed to the air, you should replace them before spending much time using the RV. They are pretty much toast!

If the voltage at the batteries is about 13.4V or higher when you are plugged into shore power then the converter seems to be doing OK. 

If you have a 3 stage charger (some converters are 3 stage) you will see voltages in the 14V range during the early stages of charging a battery which has been discharge 20-50% or more.

Thanks, appreciate the info.  I replaced all three batteries.

Just today though it seems like the new house batteries are not holding a charge, they were way down, like 11 volts. These are the costco GC2 batteries. The date on them is 7/17. Two 6 V batteries in series. RV has been plugged in for weeks.

I put the automotive charger on them but still not sure if they are charging. 

How can I tell if my converter is workin? I checked the fuses, they are OK. I checked the connections, they are OK.  I checked the power to the converter, that's OK.  It has a remote monitor, just the little dongle with one green light, it continues to function, seems to be ok.  This unit is about two years old. As I said above this is the progressive dynamics model which is so popular.

Should I pull it out from under the cabinet and use the 12 V tester on it?

I'm wondering if the wire that carries the current to the house batteries needs to be checked.

If you're plugged into shore-power, make sure your house-battery disconnect switch is not switched off (in disconnect mode.) In all the motorhomes I've seen, the house-batteries won't charge if that switch is off, but the house lights will still work. I understand some motorhomes may have been wired differently, but I don't know which ones.

Testing the converter (charger) is easy enough without removing anything. Once again, make sure you've got shore-power, and your disconnect switch is on - not in disconnect mode. Measure the voltage at the house-batteries without disconnecting them. If your charger is working, you should see greater than 13 volts. If there's significantly less voltage, there may be a problem. We can help you troubleshoot if that's the case.

Kev

I definitely have a problem.  The house battery cutoff switch is definitely on. 

I bought and installed these new house batteries two weeks ago, at first everything seemed fine, the battery monitor panel showed max, I have to admit I do not remember if I actually checked the voltage. Everything working fine.  Has been plugged in to shore power continuously.

Yesterday I went in the coach, right away I could tell the 12v system not right, house batteries were at 11 volts, lights very weak, intellitec system not working properly. I put the automotive charger on them, immediately lights are normal, Intellitec system working properly.

Yesterday afternoon I put the automotive charger on high (15 amps) for a couple hours, after about an hour charger starts flashing "bad battery".

I left the automotive charger on "trickle" for about 16 hours.  This morning I get 12.1 volts across both batteries, 6.04 and 6.06 across each battery individually.  This is with shore power and the converter definitely getting juice. As you say above I should be getting 13v plus.

The remote pendant for the three stage converter was flashing storage mode, I manually changed it to boost mode, still just 12.0 or 12.1 volts at the batteries.

My theory is that my previous house batteries were not bad at all. The problem is the converter or maybe the connection from the converter to the battery bank.

When the dew dries I'm going to crawl under and look at the wire from converter to battery bank.

Correction: the remote pendant was in normal mode, not storage mode.
Either way, still not getting the right amount of power to the batteries.

Manual recommends this step:

    Loosen the screw on the positive terminal and disconnect the positive wire. Read the converter output voltage using a
DC voltmeter. If the voltage is above 13 volts, the converter is working properly.

Will try that shortly

Mosagra said:

Correction: the remote pendant was in normal mode, not storage mode.
Either way, still not getting the right amount of power to the batteries.

Manual recommends this step:

    Loosen the screw on the positive terminal and disconnect the positive wire. Read the converter output voltage using a
DC voltmeter. If the voltage is above 13 volts, the converter is working properly.

Will try that shortly

Click to expand...

No. Disconnect the negative terminal first.  If while disconnecting the positive cable and the wrench accidentally hits some metal, it will short out and the battery could explode.

I unhooked the batteries completely.

I double checked the AC to the converter, 125v.

I pulled out the converter, I pulled all three fuses, they all show continuity, I reseated them, hooked both ground wires back to converter, plugged it in, zero output. Just to be triple sure I plugged it in to a different AC outlet, still dead.

Diagnosis: converter needs to be replaced. 

Probably my old batteries were ok and I misdiagnosed the problem though I will say they  had showed some symptoms of decline previously.

I ordered the 70 amp version to replace it.

technically, this unit is still under warranty since I bought it in November 2015. However, I do not have time to send it back and ask them to check it out and so forth. We have a trip coming up next Friday, six days away.

Send it back to them anyway.  Keep it as a spare or sell it.

We're glad you've resolved the problem. Have a good time on your trip, and look at the bright side... you've got new batteries.   

Kev