Dead Batteries

[kamakalama]

Trying to understand why my house batteries were discharged.

I Picked up the coach from storage today and found the house bank completely discharged. Something like 8.4 volts.

The batteries were left fully charged a couple of weeks ago. The house bank was shut off at the 12v disconnect panel switch.

Wondering what loads are present after the 12V disconnect is engaged?

Headed south in the morning.

Best of the holidays to everyone

[BFlinn181]

There are many parasitic loads that bypass the battery isolation switch. LP detector, perhaps thermostat, radio presets and clock, etc. An actual physical switch that disconnects the batteries from the house is the only sure way to store without power.

[GaryKD]

Hi kamakalama,
In addition to the previous post, consider:
1. inverter left on?
2. battery maintenance
3. battery age/condition

The year of your coach and the age of the batteries is not mentioned. If the batteries are flooded, have the water levels been meticulously maintained? With the batteries fully charged, do a load teat on each battery. This will tell you the true condition of coach batteries.

[kamakalama]

An actual physical switch that disconnects the batteries from the house is the only sure way to store without power.

Is there a manual switch for the house bank somewhere? I know there is a switch in back for the chassis batteries.

Could there be enough parasitic loads to discharge a 600AH bank in 2 weeks?

The coach is a 2014 so the batteries are good. I checked the water in them just a few weeks ago. Since new, I never have needed to add water. I wonder if there is a loose battery cable that got disconnected when I had the battery drawer out to check the water levels? I'll check that tomorrow.

If the disconnect is engaged, does the inverter have 12 volt supply available?

Before putting the coach in storage, I ran the generator for about 1.5hrs. The voltmeter was showing 13.4 volts when the disconnect was engaged. Once the disconnect is engaged, the display shows "no inverter connection" so there is no way to further monitor anything. Hence you can't check to see if there is still a 12volt load present.

[KIX]

Originally Posted by kamakalama

................The coach is a 2014 so the batteries are good......................

You're assuming the batteries are all good because of their age. Batteries, like everything else, can go bad. A cheap way to make sure their good is to test them using a hydrometer available at almost any auto parts store. If you're not sure how to use one you could Google for instructions.

[OldToolmaker]

I'm not afraid of being insulting. I don't like to be insulting but I gotta ask.

Are you sure the batteries were dead? Bad connections can give low voltage readings.

600 AH is a lot of power to lose.

I live in a 30 year old RV and sometimes when I think my battery pack is suddenly empty, if I'm not too tired and I remember to check the plug for my voltmeter. If I'm lucky I'll find that I was panic'd for nothing.

[BFlinn181]

After turning the disconnect switch off, remove one battery cable and put a multimeter set to amps in the gap. See how much parasitic power is present. It will also give you a chance to clean the battery connection, but I doubt if that's the issue. Checking a battery at the end of charging is always a bad idea. While a battery is charging, more power is being put into the plates inside the battery than they can absorb. Immediately after disconnecting, a reading of voltage will read the excessive charge that hasn't been absorbed into the lead plates and will read high. Always let a battery sit for at least an hour or two before trying to take an accurate rested state charge.

[kamakalama]

Checking a battery at the end of charging is always a bad idea. While a battery is charging, more power is being put into the plates inside the battery than they can absorb. Immediately after disconnecting, a reading of voltage will read the excessive charge that hasn't been absorbed into the lead plates and will read high. Always let a battery sit for at least an hour or two before trying to take an accurate rested state charge.

I thought about it some more and think this comment points out my mistake ... the batteries probably weren't fully charged when the coach was stored.

I also need to get a handle on the actual battery load when the coach is stored.

Thanks everyone for all the input

["007"]

Your Gen will take some time to charge you batteries of the inverter/converter most of us maybe able to leave the coach plugged into a 110-120 power source while coach is stored.
Quickest way to charge the batteries is with a stand alone Battery charger.
If you can start your coach and are now going south in morning your Bird System is going to recharge all your batteries as your traveling and also when parked at camp ground.
The biggest drain on the house batteries is the LP Detector if the switch, in display area, is not off to disconnect it, some of us are wired to chassis batteries but you may have wired to house.
Here is link to explain your Bird System operation and battery info found in QT's # 3.
When ever your reading battery voltage off the BDS you are reading the charging voltage from converter or alternator when plugged in or engine running your battery voltage would be when all shore power or engine is off.
Have your BDS on all times using coach, check the battery cables both battery and the chassis frame for good tight clean connections Gen, inverter/converter included.

[GaryKD]

Hi kamakalama,
Answering post #4, yes there is a disconnect switch for the coach batteries. On the same panel where the tank gages are located there should be a rocker switch labeled use/store. This is the disconnect switch for the coach batteries. With the inverter on, put the coach in store mode. Go check if the light(s) on the inverter remain on or are off. An inverter may draw down batteries pretty quickly, like a day or two. It all depends on the condition of the batteries, the size of the inverter, etc.

[newmarpusher]

Originally Posted by BFlinn181

There are many parasitic loads that bypass the battery isolation switch. LP detector, perhaps thermostat, radio presets and clock, etc. An actual physical switch that disconnects the batteries from the house is the only sure way to store without power.

Wow, that's just a plain weird setup if true. My current Winnebago DP has a disconnect switch at the entrance door. It triggers a relay in the battery compartment. That relay is the ONLY thing on the battery when the switch is off. I turn mine off for the winter and 4 months later, the batteries are still at 13+ volts.

What is the purpose of a battery disconnect switch that leaves parasitic loads on the battery when turned off? You may as well just not use it if that's the case.

["007"]

The thermostat would be shut off with its own switch, LP Detector on some gas and DP' have a switch in display area, the radio, clock, ECM, TCM work off the chassis battery which on DP coach may have its own battery disconnect.

House battery disconnect:

[BFlinn181]

If everything was shut off with the battery disconnect switch, where does the energy come from to trigger the solenoid back on after storage???

[palehorse89]

Originally Posted by BFlinn181

If everything was shut off with the battery disconnect switch, where does the energy come from to trigger the solenoid back on after storage???

From the "open side" of the switch...... when the switch is closed, its powered up, no battery load till closed.........