House batteries & LP alarm

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

Tflynn01

New member
Joined
May 21, 2022
Posts
2
Location
KC
LP alarm started beeping recently. I initially thought we had a gas leak but also realized that our house & chassis batteries could be shot. I replaced all of the batteries today as they were 4 years old. Hooked everything back up but the alarm started sounding off loudly. As I went to disconnect the house batteries I noticed that one of the positive battery cables was noticeably warm. Can anyone help me with this issue? We’re new to this 2003 Fleetwood Tioga.
 
As I went to disconnect the house batteries I noticed that one of the positive battery cables was noticeably warm.

Welcome! I see that is your first post here.

That battery cable getting warm means either the battery is being charged or discharged at a high current rate. Are you plugged in with shore power or are you boondocked or what when the battery cable is getting warm?

First, let's find the cause. The alarm is from the battery gases because of the high charge or discharge rate of the battery. The alarms can be triggered by more gasses than they are designed for.

-Don- Reno, NV
 
Was there any sparking when you connected the batteries?

If you have a good meter you can set it to amp mode and insert the leads between the battery terminal and the battery cable and it will read how much if any amperage is being drawn.

Then it's a matter of finding out what is drawing the current.

I'd hate to think you replaced 4 year old batteries for a current leak.
 
Heat requires current so there's either charge or discharge current present. There aren't typically any large house currents unless you're running an inverter, but a converter is nominally 50A so if it was charging that could be where the current is coming from.

Along with current there has to be some resistance for heat to be created. A good connection even at 50 amps will not get warm, so that cable, termination or battery connection is loose, corroded or damaged.

As a general observation, LP gas detectors will go off with outgassing flooded batteries. Batteries typically only gas under charge, so it's implied that the LP alarm and warm cable together, this event happended when charging. One can easily measure connection integrity but if one is suspect, it probably merits reviewing all of them.

Mark B.
Albuquerque, NM
 
Welcome! I see that is your first post here.

That battery cable getting warm means either the battery is being charged or discharged at a high current rate. Are you plugged in with shore power or are you boondocked or what when the battery cable is getting warm?

First, let's find the cause. The alarm is from the battery gases because of the high charge or discharge rate of the battery. The alarms can be triggered by more gasses than they are designed for.

-Don- Reno, NV
We are parked at the house with no electrical supply to the unit. I have checked @ rechecked the connections on the chassis & house batteries. (All are new batteries). When I start the RV there is a loud warning sound coming from the LP gas alarm. Red positive cable on the first pic is the one getting warm. Its connected to the electrical items in the third pic.
 

Attachments

  • 1C30C64E-CC92-4424-9B09-85485BD6E380.jpeg
    1C30C64E-CC92-4424-9B09-85485BD6E380.jpeg
    248.9 KB · Views: 10
  • A09BDFBA-6CA1-4E8A-82A6-94AC03D78D24.jpeg
    A09BDFBA-6CA1-4E8A-82A6-94AC03D78D24.jpeg
    252.4 KB · Views: 10
  • 41B6BD65-4FAE-4495-807F-5E53AB827364.jpeg
    41B6BD65-4FAE-4495-807F-5E53AB827364.jpeg
    250 KB · Views: 10
As mentioned above, the fact that it is getting warm indicates a high current through it. Since it isn't connected to shore power we have to assume that the current is from the battery and not a charge current. If the alarm is due to a problem with the battery, it would mean that the battery is boiling, which is quite possible since that cable is heating up as something is causing it to be discharging at a high rate. To know what is happening you really need to have a volt/ohm meter. You could put it in series to measure the amps it is drawing and the volt meter would allow you to monitor the battery voltage, which is bound to be dropping if it is discharging at a rate high enough to heat up the battery cables. The third picture seems to be of some sort of terminal block. Exactly where it goes is only a guess but it probably supplies all 12V power to the coach. There should not be any connection between the coach 12V system and that of the chassis when the engine isn't running.

One last thought, just to be safe make sure that you have the propane valve closed to eliminate any possibility that you have a propane leak in addition to whatever is causing the battery discharge.
 
Though we call it an "LP Detector" it is really an "Explosive Gas" detector. Many explosive gasses. LP, Methane, Butane, Spray can propellent. Alcohol, Gasoline and more.
And one thing that is NOT a gas can also beep 'em... LOW BATTERY VOLTAGE.
 
I note that those are 6v batteries and therefore have to be connected in series/parallel pairs. I can't verify proper wiring from the photos, but the red cable in the photo looks like it is positive to positive instead of positive to negative (series) wiring. Can't see the battery terminal polarity signs, but check the battery wiring carefully. Especially if you replaced 12v batteries with 6v GC types - the wiring is different.
 
Measuring some actual voltages and currents would be a useful thing. That would reveal if there's a battery, cable or system problem. The LP detector would be something to troubleshoot separately, whether it's actually detecting hydrocarbons or has a power issue.

Mark B.
Albuquerque, NM
 
From your pictures I can only identify 3 6V batteries, which is not right,there must be multiples of 2,4,6, 8 etc. Will you post a picture of the entire house battery bank?
I agree with previous replies as to cause of, and testing for a hot/warm battery clamp. That may even be damaging the new battery.
 
You could put it in series to measure the amps
I wouldn't put most ampmeters in series with a thick wire that is warm to the touch. Most people will probably blow out the ampmeter.

I would use a higher current 12V bulb (No LEDS!) in series and then check to see what is making it light up so bright-- which it will be bright if the thick cable feels warm to the touch.

-Don- Reno, NV
 
Your LP detector should be a CCI 7719 that shuts off the LP if it smells a leak. When you remove the battery cables and reattach, the alarm will go off loudly. There is a switch on the detector that you need to turn off and then back on to quiet the detector. The detector will go through a start up sequence while making some soft beeping sounds and then will quiet down.

Richard
 
Back
Top Bottom