Adding a 2nd battery.

[Bell]

I paid RV country to add a second battery to my 2021 Reflection 295RL, and they wired the batteries wrong. Now the trailer beeps and blinks end of life code. Now, no matter what I do, even with a new battery, I can't get the trailer to stop beeping EOL. Is there a way to reset the system? Or does anybody have any ideas as to what to do now other than take it back to RV country?

[TedS]

What was wrong about the battery wring?

[Bell]

The tech had battery one positive and negative jumping to Battery 2, which is correct, but he had both of the main +/- going to b1 only, making b2 drain completely into b1. Once the trailer recognized a problem with the batteries, it stopped the converter from charging them. I can't get the system to detect the battery is new and allow the converter to start charging again. When I turn on the converter resettable breaker or turn the battery disconnect on, I hear the fan on the converter come on but then shut right back off and the battery end-of-life beep comes back on. They definitely either ruined the batteries or damage the converter in the process. I've checked all the fuses I can find, including the two 35amp fuses on the back of the converter. Any ideas would be helpful.

[Jlawles2]

Double check that he did not reverse the polarity of the batteries to each other (this would be BAD). Also verify that the negative on the batteries is definitely connected to the frame of the unit. I have seen several units where the Black wire was Positive and one unit where the white wire was negative. I vaguely remember someone having a unit with a red negative wire.

Some of the newer battery chargers will not charge a battery if it is completely drained. Have you checked the battery voltage?

Also Deep cycle batteries usually require some form of maintenance. Even the "maintenance free" ones need to be checked to ensure the electrolyte level is correct. If the level is down, it can cause the charger circuit in the converter to do strange things.

[TedS]

Is this what you see as right and wrong? They are not really right and wrong. The voltage seen by the load side is the same for either case. The converter would not know the difference. As Jlawles2 mentitioned the tech may have even momentarily reversed + and - and blown the converter output reverse connection protection fuses. The batteries will then not get charged.

[Cate&Rob]

Bell
Do you have a voltmeter that you could use to take voltage measurements at the battery terminals with the converter off and on? I would suggest separating the batteries and measuring them individually. It may be that one battery is good and the other is bad which is confusing the voltage sensing by the converter.

Rob

[Bell]

I check all of the positive and negative wiring for the possibility he reversed the polarity and don't see anything wrong. That doesn't mean he didn't cross it during installation. I'm not able to measure the voltage with the converter on because the trailer won't allow the converter to stay on long enough to measure it.

[TedS]

Check the reverse connection protection fuses on the converter output.

[TedS]

According to a WFCO converter manual, the converter fan will run momentarily when first connected to shore power. That just indicates that the converter is receiving power.

[Jlawles2]

You will have to check your specific wiring, but by using the battery disconnect (remove key) it should isolate the converter from the batteries.

A second way to check the converter would be to disconnect the negative wire from the batteries and see if the lights and such in the unit still have power. This would signify that the converter is working.

[Bluestreak]

Is this what you see as right and wrong? They are not really right and wrong. The voltage seen by the load side is the same for either case. The converter would not know the difference. As Jlawles2 mentitioned the tech may have even momentarily reversed + and - and blown the converter output reverse connection protection fuses. The batteries will then not get charged.

A little sidebar here: Right and Wrong are a little strong. Wrong in this case still functions to parallel the batteries, but it creates a primary/secondary relationship between the two batteries that short-changes the secondary battery for charging and discharging. The right way makes the two batteries equal participants in charging and discharging, with current flowing through both batteries equally. This makes sure all available current is sourced or delivered equally to both batteries. I found the wrong wiring on my new trailer and quickly rearranged one wire to make it right.

[Jlawles2]

Hopefully the OP chimes in if they find the issue. I'm wondering if the battery disconnect has been activated and that is why the converter is flashing EOL. No battery connected for it to monitor.

[Scott'n'Wendy]

I'm not able to measure the voltage with the converter on because the trailer won't allow the converter to stay on long enough to measure it.

To the best of my knowledge, a converter will output 12v even without a battery. Could be some models that don't. But, if it were me, I would disconnect the battery charge wires at the converter. (With the trailer unplugged). Then power up the converter. It should output 12v. If it does, converter ok, batteries/wiring is the issue. Faulty battery(s) or faulty wiring. If it does not output 12v, double check those reverse polarity fuses you said you checked earlier. With a meter. Not just visual. If those fuses are good, ensure you are getting 120vac to the converter. You could have a bad breaker. If the 120 is good, you need a new converter.

[Fiveofastback]

Is this what you see as right and wrong? They are not really right and wrong. The voltage seen by the load side is the same for either case. The converter would not know the difference. As Jlawles2 mentitioned the tech may have even momentarily reversed + and - and blown the converter output reverse connection protection fuses. The batteries will then not get charged.

Exactly as pictured it has to be or the secondbattery will not charge correctly or balamce the 2 batteries. 45 years as electronics tech

[Fiveofastback]

To the best of my knowledge, a converter will output 12v even without a battery. Could be some models that don't. But, if it were me, I would disconnect the battery charge wires at the converter. (With the trailer unplugged). Then power up the converter. It should output 12v. If it does, converter ok, batteries/wiring is the issue. Faulty battery(s) or faulty wiring. If it does not output 12v, double check those reverse polarity fuses you said you checked earlier. With a meter. Not just visual. If those fuses are good, ensure you are getting 120vac to the converter. You could have a bad breaker. If the 120 is good, you need a new converter.

Most older converter may give an output with no load but new tech has eliminated this function do to miswiring or polarity reversal.

Positive off converter + to battery A+ parallel connections to battery B+ and B-ground of converter and chassis together out of battery B- negative
thIs will give the converter/inverter circuitry a reading of the sate of both batteries as one allowing it to turn on and charge both batteries at same rate flowing current across both.