View Full Version : 12 volts lights run battery down

05-18-2013, 01:04 PM
We have a 2005 Forest River Cardinal 5th wheel. We are having a problem with the 12 volt lighting. They run down the battery. It is a new battery but when plugged into shore power, it only registers 2/3 full on our monitor inside the RV. When check by meter it registers full. We have had the converter checked and it registers Ok. Any ideas??

Cheif 2
05-19-2013, 05:13 AM
You said the 12v lights run the battery down. Is that the case when you are plugged into shore power? Have you checked just the battery voltage when plugged in and after using the 12v lights for a considerable time? You need to do so after disconnecting the battery from the camper electrical system? You need to try to isolate the problem a little more before getting to the source of the problem. Let me know what you find.

05-19-2013, 09:32 AM
Not sure of your question. Chief is correct, you need to do more investigating.
The converter is not designed to completely charge the battery(s) to full charge--only a regular battery charger will do that. But the monitor panel should show full charge on the lights when plugged in to shore power--if not, maybe the panel is not correct since the meter shows the battery to be charged?
How long have you had the trailer--why a new battery. It is actually being drawn down by use? Maybe you are not aware of what is on--basement light, something else?
And it isn't impossible to have a bad new battery...

05-19-2013, 04:26 PM
The trailer is plugged in and we turned on 3 of the 12 volt lights. Within 2 hours the meter in the trailer dropped to 1/3 power. It is a brand new battery, just days old. The previous battery was only 10 months old when we started having a problem and was bad when tested and was bulging out the sides.

We turned the lights out and within 2 hours with the trailer plugged into shore power, the meter read 2/3 power. When tested with a tester, the battery shows full. The only things running with the shore power on is the microwave ready light and the Co2 monitor green light.

When the problem started we were camped and my husband noticed the 12 volts lights go way down very quickly and the alarm on the Co2 went off. We cannot find the source of the probem. We had the converter voltage checked and it checked out OK.

Thank you for the suggestions. We will try it and see what we find.

Cheif 2
05-19-2013, 07:03 PM
The converter should be able to keep up with your 12 volt demand. Is there any possibility that you have a battery switch turned off not allowing the converter to properly charge the battery. Usually converters have a couple of fuses in them. I would also check the fuses.

05-19-2013, 08:37 PM
Who checked the converter? Don't check it with the leads to the battery connected--it will show battery charge.
I assume you have checked all the 120 volt breakers?
Something is not allowing the converter to charge the battery. As Cheif said, be sure you don't have a 12-volt cutoff that is tripped/open.

05-22-2013, 08:38 AM
Thanks for the input. We will double check the fuses and the breakers. Also check the Co2 alarm since it sounded when the lights went dim.

Cheif 2
05-22-2013, 08:42 AM
The CO2 detector is wired in to the 12V system in the camper. Low voltage will cause it to sound. Disconnect the battery to the camper and check the voltage coming from the converter while being connected to shore power.