I suspect you are referring to your CONVERTER not the optional Inverter some folks have installed.
The CONVERTER should be putting out 13.6VDC at all times when connected to shore power. You should be reading this voltage on your battery terminals.
I have one of those inexpensive digital multimeters from WALMART-LOWES-Any Number of auto parts stores to measure DC voltages to help me figure out what is happening.
You can measure the DC VOLTAGE directly on the battery terminals without the Shore power cable connected to 120VAC. If the battery is fully charged it will read around 12.6-7VDC. If it reads less than 12.0VDC then the battery is 50% discharged and considered a DEAD battery if your reading is less than 10.5VDC.
A $10-$20 multimeter will look something like this
When you plug the trailer shore power cable into 120VAC then you should read 13.6VDC on the trailer battery telling you that the CONVERTER is operating and should now be charging your battery.
Consider this handy chart showing the state of charge for deep cycle batteries.
If your trailer is equipped with SMART MODE charging technolog (most trailers after 2012 already have this feature built-in) then your battery should get recharged back up to 90% charge state is as little as three hours.
Consider this brochure report from Progressive Dynamics on how long it takes to charge deep cycle batteries. This is battery science so not many short cuts allowed here...
"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.
14.4-VOLTS (Boost Mode) โ Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.
13.6-VOLTS (Normal Mode) โ Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.
13.2-VOLTS (Storage Mode) โ Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."
It sounds like to me your converter is not charging your battery. Perhaps the battery terminals got REVERSED and some fuse have been blown. A quick way to determine if the battery terminals are reversed is to look on the battery case and find the word "NEG" or the symbol "-" and hand trace that connected battery cable which should go to a FRAME GROUND connection very close to where the battery is installed. If this is REVERSED than correct this problem before changing out any blown fuses otherwise they will just blow again. You should find a in-line fuse or circuit breaker module very close the the positive terminal of the battery and also find a couple of fuses in the POWER DISTRIBUTION Center where all of your 12VDC fuses are located. These fuses may be marked REVERSE POLARITY. Sometimes these fuses are actually on the CONVERTER unit depending on what model of converter you have installed.
Hope this helps with your situation...
Just my thoughts
Roy Ken
The CONVERTER should be putting out 13.6VDC at all times when connected to shore power. You should be reading this voltage on your battery terminals.
I have one of those inexpensive digital multimeters from WALMART-LOWES-Any Number of auto parts stores to measure DC voltages to help me figure out what is happening.
You can measure the DC VOLTAGE directly on the battery terminals without the Shore power cable connected to 120VAC. If the battery is fully charged it will read around 12.6-7VDC. If it reads less than 12.0VDC then the battery is 50% discharged and considered a DEAD battery if your reading is less than 10.5VDC.
A $10-$20 multimeter will look something like this
When you plug the trailer shore power cable into 120VAC then you should read 13.6VDC on the trailer battery telling you that the CONVERTER is operating and should now be charging your battery.
Consider this handy chart showing the state of charge for deep cycle batteries.
If your trailer is equipped with SMART MODE charging technolog (most trailers after 2012 already have this feature built-in) then your battery should get recharged back up to 90% charge state is as little as three hours.
Consider this brochure report from Progressive Dynamics on how long it takes to charge deep cycle batteries. This is battery science so not many short cuts allowed here...
"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.
14.4-VOLTS (Boost Mode) โ Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.
13.6-VOLTS (Normal Mode) โ Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.
13.2-VOLTS (Storage Mode) โ Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."
It sounds like to me your converter is not charging your battery. Perhaps the battery terminals got REVERSED and some fuse have been blown. A quick way to determine if the battery terminals are reversed is to look on the battery case and find the word "NEG" or the symbol "-" and hand trace that connected battery cable which should go to a FRAME GROUND connection very close to where the battery is installed. If this is REVERSED than correct this problem before changing out any blown fuses otherwise they will just blow again. You should find a in-line fuse or circuit breaker module very close the the positive terminal of the battery and also find a couple of fuses in the POWER DISTRIBUTION Center where all of your 12VDC fuses are located. These fuses may be marked REVERSE POLARITY. Sometimes these fuses are actually on the CONVERTER unit depending on what model of converter you have installed.
Hope this helps with your situation...
Just my thoughts
Roy Ken
