Batteries Not Charging & Can't Find the Converter

ckersey · 09-13-2019, 04:18 PM

My wife and I bought our first camper, a new Sprinter 3571FWLFT about a month ago. We finally got electricity run to the land where we are keeping the it. I was excited to get it all going for the first time. Everything seemed to be working, but when I came back the next day, the thermostat didn't have power so the A/C wasn't running.

Checked the batteries, and they were down to 3 volts. Plugged in to shore power, it isn't charging the batteries. The converter breaker is on, and has current. I checked in the basement, and there is a automatic transfer switch that has current to it. With the batteries charged, the inverter has current. I assume there is a converter somewhere (I have a manual for one in the paperwork), but I can't find it anywhere.

I am currently plugging a battery charger into the camper and hooking it to the batteries, but would like to get it working correctly.

ctbruce · 09-13-2019, 04:35 PM

If you have a battery disconnect switch turn it off. Batteries wont charge if it is on.

**JRTJH** · 09-13-2019, 04:35 PM

If you bought it "about a month ago" and just now are trying to charge your batteries (after the trailer sitting for that month with no power) chances are that your battery is dead, as in "won't accept a charge". You might get some "residual charge" from a stand alone battery charger, but I'd suspect the battery is beyond repair. Any automotive supply store can load test the battery for you. Charge it as much as you can with the stand alone charger, take it to the store and ask them to "load test" the battery. That'll tell you whether you need new batteries or not. I'd guess you probably do.

Now, as for the location of the converter. It's usually located attached to the back side of the power center. Before proceeding, DISCONNECT THE TRAILER FROM SHORE POWER... If you open the door to where the fuses and circuit breakers are located, you'll see two screws. Remove them, pull the top of the door away from the converter and lift the bottom out of the converter. You'll find four #2 Roberts screws, remove them and the power center will pull away from the wall. There is just barely enough cord behind the power center to pull it slightly away from the wall and turn it sideways. Once you do that, you'll likely see the converter/charger bolted in place behind the circuit breakers. My guess is the converter/charger is OK and your issue is a bad battery.

Canonman · 09-13-2019, 05:01 PM

Quote:

Originally Posted by ctbruce

If you have a battery disconnect switch turn it off. Batteries wont charge if it is on.

I don't understand???

ckersey · 09-13-2019, 05:06 PM

Even if the batteries are dead, if I am hooked to shore power and the converter is working, shouldn't I read 12 volts at the battery terminals?

**sourdough** · 09-13-2019, 05:11 PM

If it's a new trailer and you were plugged into shore power the entire time either the battery was on its last leg in the first place, the converter is not working (I doubt it) or the battery disconnect switch is activated.

Canonman · 09-13-2019, 05:17 PM

Quote:

Originally Posted by ckersey

Even if the batteries are dead, if I am hooked to shore power and the converter is working, shouldn't I read 12 volts at the battery terminals?

Actually you should re more than 12v at the battery. If the converter is charging. Check the resettable fuse link at the battery distribution terminal. You'll find it close to the batteries.

LHaven · 09-13-2019, 05:17 PM

Quote:

Originally Posted by Canonman

I don't understand???

Not sure about your model, but many later models have a battery disconnect switch, often in the forward cargo compartment. See this discussion.

ckersey · 09-13-2019, 05:27 PM

I have two disconnects in the front compartment. One I believe is battery and the other is on the wire that runs to the inverter. That wire has a breaker on it, and I have pushed the reset on it. I haven't seen another breaker. I have tried flipping that disconnect switch and when I do, I lose the lights and thermostat inside the camper.

**JRTJH** · 09-13-2019, 06:16 PM

Quote:

Originally Posted by ckersey

Even if the batteries are dead, if I am hooked to shore power and the converter is working, shouldn't I read 12 volts at the battery terminals?

Logic would say, Yes you should have 13.6 VDC from the converter/charger. BUT: if the battery is defective, there are protection circuits in the converter/charger that will shut it down rather than allow it to be exposed to a shorted battery and damage it....

To check your theory, completely disconnect the battery from the cables, DO NOT ALLOW THEM TO TOUCH EACH OTHER OR GROUND. With the trailer connected to shore power, the battery disconnect switch in the "CONNECT" position and the converter/charger operating, you should read 13.6VDC across the battery cable terminals. If you do, the trailer is functional. If you don't, let us know and we can go through a couple of troubleshooting steps to verify where the problem exists.

NOTE: If you do not have 13.6 VDC across the battery terminals, turn the battery cutoff switch to the other position (to verify that it is functional and correctly set)...

ckersey · 09-13-2019, 06:19 PM

I will give that a shot in the morning.

ctbruce · 09-13-2019, 06:57 PM

Quote:

Originally Posted by Canonman

I don't understand???

If the disconnect is on, then the battery is disconnected from the converter and the charging circuit. To full connect the converter and the charging circuit, you have to turn off the disconnect. I know. Really confusing.

bobbecky · 09-13-2019, 06:59 PM

Quote:

Originally Posted by ctbruce

If you have a battery disconnect switch turn it off. Batteries wont charge if it is on.

The ON and OFF of these switches is a poor method of labeling a battery disconnect switch. They could be labeled CLOSED and OPEN, or CONNECTED and DISCONNECTED, or any other way. If a disconnect switch is labeled ON, is it ON meaning disconnected or ON meaning the battery is connected? Just a bad situation. If the red key of the switch can be removed by pulling it straight out, it has disconnected the battery from the main electric panel and the battery will not get a charge from the converter and the battery will not provide power to the panel. If the key can not be removed, then the battery is connected to the system, will get charge from the converter and the battery can provide power to the panel.

ctbruce · 09-13-2019, 07:17 PM

If your disconnect is a key. Mine is a push pull switch. On is in and disconnected/off no charging. Out is off and connected/on and battery charging. You have to use your noodle to keep it straight.

ckersey · 09-15-2019, 05:02 PM

Had time to play around with it today. No matter how I turn the disconnect switches, I don't get any current to the battery. Pulled the panel, and no voltage coming out of the converter. Checked both fuses in it, and they are ok. The fan never comes on, so I think it has to be a bad converter.

Guess it will go back to Camper World for some warranty work.

**chuckster57** · 09-15-2019, 05:11 PM

Quote:

Originally Posted by ckersey

Had time to play around with it today. No matter how I turn the disconnect switches, I don't get any current to the battery. Pulled the panel, and no voltage coming out of the converter. Checked both fuses in it, and they are ok. The fan never comes on, so I think it has to be a bad converter.

Guess it will go back to Camper World for some warranty work.

I would call them and ask if you can bring in the defective converter for a warranty exchange. That way you have to drag the whole trailer in and watch it sit on the lot while they wait for its turn to look at, then wait for authorization. Then wait for another one, then wait for a tech to install....if the converter has failed, it’s a no brainer, and IMO the dealership can deal with the “waiting period”. Odds are they have one in parts on the shelf, if not they can order one and have it the next day, ask me how I know.

ckersey · 09-15-2019, 05:48 PM

Thanks, that's a great idea. I will call them in the morning and see if they will do that. Got to get it fixed this week. My wife just booked our first outing in it for next weekend.

n1282x · 09-19-2019, 07:41 AM

I would pull out the breaker box as others have said and then locate the battery charger module in the rear of it. On the battery charger near the output wires there are two large fuses about 25 or 30 amps each depending on model pull those out and make sure they are good they are commonly blown if you hook up the batteries backwards

marktaco · 09-19-2019, 08:17 AM

In many of the new trailers, the converter is built into the main 12volt/110 volt breaker/fuse box. In mine, the box had an upper and lower level and the inverter was on the lower level. Hope that helps.

pdaniel · 09-19-2019, 08:31 AM

Quote:

Originally Posted by ckersey

Even if the batteries are dead, if I am hooked to shore power and the converter is working, shouldn't I read 12 volts at the battery terminals?

To test converter output the converter needs to be disconnected from the batteries either by disconnecting a terminal lead or the cut-off switch. Then, with shore power connected, measure the output voltage at the converter. If the converter is a WFCO there should be in the neighborhood of 14 or so VDC.

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