12 Volt House Power

[gwtriker]

We are trying to leave on an extended vacation in our Bounder 34J. We have a problem when we disconnect from the AC line. The 12 system kicks in, but quits working after about 10 to 15 minutes The generator will not turn over when this happens. Things start to work again when we re-connect, or start the engine.

The house batteries are new and have been charging for three days while the coach was plugged to the line power and the terminal voltage is over 12.5 volts when everything quits working.

Any suggestions?

[vtbigdog]

I am assuming you are talking about the house batteries.

I would check the fluid level in the house batteries.

The reason 12V works when you reconnect to shore power or start the engine is because your inverter is supplying the 12V power. When you disconnect, only the batteries are supplying 12V power.

You may also want to check the battery terminal connections.

[gwtriker]

As I mentioned earlier, the house batteries are new. Fluid levels are good and connections should be good. On additional attempts to resolve the problem, I can hear a relay or solinoid click when the lights and other things in the house go off. I have not located what ever it is that is clicking on an off.

[dickandlois]

Check and see that all the jumper cables for the 6 volt batteries are connected in series. Positive on one to Negative on the other and read 12 volts across the remaining positive and negative terminals of the sets. You now have 2 -- 12 volt pairs

Then check the jumpers that connect the 12 volt pairs in parallel are correct. Negative on one pair to Negative on the other pair. Then check the positive side.

It is very easy to get them wrong.

Then check the Positive cables feeding the chassis circuits are correct and then check all the ground cables are all connected.

Should you get some sparks when connecting the grounds, something is wrong. You may get a little spark because of something drawing a little current. Its that hot sizzling ark that means something is not right.

The clicking sound is most likely coming from the contractor in the coach 12 volt circuit. it should stay energized if things are connected properly.

Check the 12 volt connections between the chassis and coach batteries are correct. There are allot of connections and its real easy to mix them up...

Rich.

[gwtriker]

All the jumpers are in place, good grounds and terminals tight and there is only a single pair of 6 volt deep discharge batteries. In double checking, the wires from the inverter were not tight, so I tightened them up. This would mean that the batteries were possibly not getting a good charge from the inverter. It is plugged into the house again and I will check it again in a couple of hours.

The loose wires at the converter do not seem to the problem since the terminal voltage at the house batteries was well above 12.5 volts before and after what ever tripped to shut off the 12 volt power in the RV. If I don't find an answer soon, it'll be another trip to the RV service facility early tomorrow morning.

[wolfe10]

You have quite likely found the root cause if the issue-- loose connections on the inverter/charger. And, 12.5 VDC with the charger on is NOT proper. Suspect it is a three stage charger, so charging voltage in bulk mode should be 14 or more volts. After it has been plugged in long enough that the batteries are fully charged, the voltage in float mode should be 13.2-13.5 VDC.

[OkieDave]

You say that you hear a click when the power goes off. I think you have a solenoid problem.

Do you have a switch that isolates coach batteries while you are away? If so, check the switch. Then try to find the solenoid that is controlled by the switch. Perhaps by turning the switch off and on you can hear it and find it. It should be near the house batteries. If you have an isolator solenoid then there should be two solenoids. One to isolate the house batteries and the other to connect all the batteries together while your engine is running so that the chassis and house batteries are being changed while you drive and to connect all together when you use the 'starter boost' when the chassis battery is low.

These solenoids are designed to be continuous duty. If that solenoid is bad it will heat up and open the contactor and the batteries are not in the loop anymore.

Then your converter/charges will not charge the batteries and you will just have the 12v power from the converter. These solenoids are about $30 or less.