Hello, I need some advice. I purchased an old TC and on my first trip I realised the batteries were not charging when hooked up to shore power. My previous TC's converter always hummed when it was plugged to shore power, however, this one did not. I checked the connections at the converter and found the converter output was zero. I then replaced it with a Progressive Dynamic 35Amp converter. Once plugged into shore power I saw all the light blinking and check the battery connection to the converter and it showed the voltage from the battery. I then checked the output of converter and it showed 14.4 volts. Good I thought. Then after my next trip I realised again the converter was not charging the batteries. I checked on this blog and someone suggested there must be a blown fuse between the batteries and the converter. I then found the fuse and it appeared good. No change though, the converter still will not charge the batteries. I then did the following. With the battery disconnect the 12volt system doesn'twork. I used my voltmeter and checked the connectivity across the neg and positive of the battery connection on the converter and the resistance is zero. I also checked across the neg and positive of the converter and it too has a resistance of zero. I am no electrician but the resistance across the Positive and Negative terminal on the battery side of the converter and between the Positive and Negative side of the converter should not be zero but should be 1. I am at a loss as to what the problem is...any suggestions?

The problem is pretty simple; the solution might not be.Your batteries are NOT connected to the converter.OR....it might be more useful to state it the other way: Your converter output is not connected to the 12 V system in the RV, including the battery.While a meter is an indispensable tool, physically tracing the output wires leaving the converter might be necessary here. BUT....what exactly do you mean that the fuse "appeared good" ?You have a meter, test it.If it is good, you should see the converter output voltage on BOTH sides when the converter is running.

You need to investigate the systems. Older converters were giving 12 AC current for the camper and only radio + charging had small separate circuit of DC. Newer converters give 12 DC and often works parallel with batteries, so my first guess was that you did not connect old small cable for battery charging.

If the converter is producing 13.2+ volts and the battery is a bit lower.... you have an open circuit. Use that voltmeter and check voltage along the path to the battery. At some point you will drop from converter voltage to battery voltage. Need to repair, replace, adjust, clean, or tighten that point where the voltage changes.

If the converter is putting out 14V when powered up, it’s fine. If there isn’t the same voltage (or nearly so) at the battery you still have an open circuit between the two.Posted at the same time as “time”. ;)

Are the batteries new or nearly new?

Converter will not charge batteries | Good Sam Community

AnEv942
Nomad
Dec 31, 2019
Sorry not the magic bullet...its the charge line in from truck. Comes from thermal breaker that goes to umbilical cord. Previously was attached to the battery side of another thermal breaker that feeds front jacks (direct tie-in to battery). Issue was when camper batteries turned off the umbilical cord was still hot so moved it to the battery terminal thats no longer hot when disconnect off. Secondary was I added power disconnect switches to jacks- truck would power front jacks the way it was wired even if batteries off and jacks power switches off. At anyrate the black wire I show doesnt relate to your problem.

i wasnt clear on your voltage check. Was the voltage drop at load noted at the converter battery pos terminal? The Converter pos remained at 13.5?
Converter on, you should see same voltage (output) at both terminals.
Converter off, you should see same voltage (battery voltage) at both terminals.
I am curious about the battery voltage of 13.0- had you charge with somthing else?
ticki2
Explorer
Jan 01, 2020
Unplug the converter . At the panel disconnect the wires from the battery and converter lugs . Do you have continuity between the two lugs? How have you been charging batteries if the converter is not doing it? With the voltage drop in your last test between converter at 13.5v and battery at 12.7v I suspect a bad connection or faulty battery .
biggjb
Explorer
Jan 02, 2020
Ticki2
I disconnected the battery and converter on the panel and there was no continuity. I then connected the converter back to the panel and turned the converter on and the voltage coming from the converter was 13.65. however, just for giggles I checked for a voltage drop across both positive lugs of the converter and battery. There was a voltage drop of 13.65 volts. This made no sense so I tested it several times and it came out the same each time.

As for charging my battery I also have a 130 watt solar panel which kept the battery charged.
ticki2
Explorer
Jan 03, 2020
biggjb wrote:
Ticki2
I disconnected the battery and converter on the panel and there was no continuity. I then connected the converter back to the panel and turned the converter on and the voltage coming from the converter was 13.65. however, just for giggles I checked for a voltage drop across both positive lugs of the converter and battery. There was a voltage drop of 13.65 volts. This made no sense so I tested it several times and it came out the same each time.

As for charging my battery I also have a 130 watt solar panel which kept the battery charged.
I'm a little confused with your terminology . Voltage drop is a loss of voltage through wires or connection . When you say you had a voltage drop between the converter positive and battery positive lugs that would mean zero volts at the battery lug . Did you mean you had the same volts at both lugs ? Also , did you use the battery positive and negative lugs for testing . You definitely have an open circuit between the converter and battery . How and where do the solar charge wires connect to the battery ? In order to test those lugs as I suggested you would also have to disconnect the solar charge from the battery . You should have continuity between the converter lug and the battery lug . It's the only place I can see that the converter is connected to the battery .
biggjb
Explorer
Jan 04, 2020
I first want to thank everyone who gave me advice. I was so confused with the converter and the fact that the 12v system was intact as well as the 120v system. However, with the converter turn on and the battery disconnected, the converter should have operated the 12v system but it did not. I therefore thought there was a problem with 12v circuit board. I then removed it completely, pulled the board out and then rewired. While I was rewiring it, I check all the fuses. The fuses for the individual circuits were good. When I checked the two 30A fuses to protect from reverse polarity, then were burnt. These were the only fuses I did not check. I always thought the problem was the TC. When I replaced the two 30A fuses the converter started to charge the battery and when I disconnected the battery, the converter ran the 12v as well. Just to say I did not check the most obvious problem first. Thanks everyone for helping.
ticki2
Explorer
Jan 05, 2020
Electrical gremlins can be very humbling . Glad you found it .

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Converter will not charge batteries

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