2015 Montana 3402RL 12 volt not chatging

[Hoyett]

Good afternoon! Late in the season last year we had a problem with the 12 volt battery not maintaining a charge. I suspected the battery & replaced it but it still did not maintain a charge. I now assume it is the 12 volt charging system. A friend of mine mentioned that there may be a reset switch located on the wall in the batter compartment but I do not know what to look for.

I am in the process of opening up our RV for the summer and if anyone can guide me to where I can check to see if something needs a simple push button reset or replacing the (inverter)<--- I do not know if this is the proper terminology... Thanks in advance!!!

[Carl n Susan]

You wrote the battery is not maintaining a charge. I am not sure what that means exactly. Does the battery lose voltage over a period on non-use? Or does it drop voltage while being used and it doesn't get re-charged?

Periods of non-use can cause voltage drop due to parasitic loads even if the Red Disconnect Switch is used (it doesn't disconnect all 12V devices).

How old is the battery and have you had it load tested?

The battery is charged by a converter (takes 120V AC and outputs 12V DC). An inverter is a device to produce 120V AC from 12V DC

The 12V flow from the converter to the batteries is pretty straight forward. Here are the places to look. All connections should have 13.5 +/- Volts if the converter is working.

• The converter is part of the power distribution panel -Ensure the CB for it is On
• There are Reverse Polarity Fuses on the converter which protect against connecting a battery backwards. - Ensure they are not blown.
• Check the output voltage at the converter. - it should be in the 13.5V DC range.
• The power then runs to the Disconnect Switch in the Convenience Center. - Ensure the Red Key is in the position where it can *NOT* be removed. If removed, this interrupts the power charging the battery. The Disconnect Switch is not know to fail, but you can remove it to check there is power in and out of it just to be sure.
• The power next flows to the group of 50 amp self-resetting CBs behind the battery. We all know about the one that hiccups and interrupts the hydraulic system. That one also passes power to/from the converter and batteries. You want to check it and it's brother (it is in the current flow to the battery) to ensure there is 13.5V on *EACH* side of the CB.
• The last connection is the one from the 50 amp CBs to the batteries. Ensure you have clean connections and the cables are not corroded (watch out for internal corrosion under the shrink wrap).

Somewhere along this path there will be the problem. A simple VOM should find it. I hope this helps.

The most common causes are :
o - the Battery Disconnect Switch in the convenience center is in the wrong position (the Red Key should be in the position where it can't be removed)
o - The red plastic covered self resetting 50 amp circuit breakers behind the battery have failed.

[Hoyett]

Thanks! The battery is new so I have not performed a load test on it but I would hope it is fine. Then again, hope is not a good strategy.

I will look into chasing the converter charging power and see where it takes me.

Hoyett

[Carl n Susan]

Did someone accidentally connect the wires to the battery backwards when installing that new battery? It doesn't take much to blow the Reverse Polarity Fuses in the converter if so.

[BB_TX]

As Carl noted, you should see 13.5+volts from the converter to the battery when connected to shore power. You can check that at the battery terminals. If you don’t have that voltage then the converter is suspect and would be the next thing to check. Assuming you did check the battery disconnect switch for correct position.

[Hoyett]

Where is the converter located? Is it in the battery compartment or do I have to remove the panels from the storage area?

[Carl n Susan]

The converter is part of the Power Panel (circuit breakers and fuses). The panel has a black cover that opens easily.

[Hoyett]

My panel is located in the main cabin bathroom about 6 foot off of the ground. Is there a shelf back there that it sits on?

[Carl n Susan]

That's right, you have an older 3402RL model. they used to put the power panel in the bathroom. Can you take a picture of that area. Specifically the power panel? You may have an integrated converter or perhaps a separate box one. There might be a shelf for the separate converter but I can't see Montana spending the extra $$ to do that.

[dfb]

Take a volt meter when you are hooked up to shore power.. The reading at the battery should be over 12.8 volts... If you are not getting that then I would check the convertor...

[Hoyett]

I will take a photo of it when I get back to the campground. Thanks for everyone's help!!!

[rohrmann]

This is how the panel is in the bathroom of the 3402. Photos were taken when installing the Progressive EMS. The converter is located behind the vent grill area and the panel does not need to be removed to access the converter.

[Hoyett]

My power panel looks exactly like the picture previous in this post. I tried to copy it but failed.

I do not have a vent inside of my bathroom.

Hoyett

[rohrmann]

Originally Posted by Hoyett

My power panel looks exactly like the picture previous in this post. I tried to copy it but failed.

I do not have a vent inside of my bathroom.

Hoyett

The vent I described is the vent louver area of your electric panel. Behind that vent is the fans that cool the converter that is behind them.

[Hoyett]

Hello! I did notice the fan in the bottom right hand corner of the panel. I will remove the panel and investigate. Thanks again for all of the club support.

Hoyett