Ugh - I did it again! :o

T@Buhura · July 2016

Long story short - I had our NORCOLD 3 way fridge inadvertently running on battery while our T@B was plugged into 120v 15amp power (I meant for it be running on 120v).

Long story - There was a storm coming a couple of nights ago that was expected to bring hail, so I moved our trusty T@B from the parking pad on my wife's parent's driveway and moved it to their big barn (where they keep their Sprinter RV and other toys. I had it plugged in next to their detached garage running the fridge on 120v. When I moved it I powered everything off and once in the barn I plugged it back into 120v and powered everything back up and tucked it in for the night. The next day (yesterday) I went to check on it and was really perplexed when our voltmeter was total dark on it. I tried my multimeter and it barely registered any voltage on the battery. I pulled the battery and quickly put it on a tender. I checked the fridge and it seemed cold, I also checked the 120v outlets inside and out of the T@B and they were definitely putting out 120v. After nearly an hour I checked the battery again and it's reading 12.6v (not the 13.8v I customarily find when it's been on the tender) but seems like it's fine. I was still confused by the battery readings yesterday... I still left the battery on the charger at 2amps since yesterday. This morning I went back to check on the T@B again to check that the fridge was still cold. It was cool not cold. I decided to pull the food out of it and bring it into the house and in doing so decided to power the fridge off and... Face Palm - I had switched it to battery when I powered it up once it was in the barn.

This is the second time I've done this, and nearly on the anniversary of the first time (when in Tok, AK last summer). Only that time the battery was completely toast and I had to pay the AK premium for a new battery. This time the battery seems to have recovered although I'm sure it's compromised. I'll hoping to find an auto parts store to have them load test it. We'll need it again to spend weekend at AirVenture.

How much current does the little 4 port converter put out on 12v to charge/maintain the battery? Now I know for sure it ran at a deficit and that's what happened to the battery. I just cant believe it did it again... only this time it really took it down to 0.1v. Last year it was down to 5v and it wasn't recoverable. This time it seems to be back. The difference is this time the battery is 12 months old and last year it was 1 month old. Ld Acid battery chem both times.

It just seems there's never a good time to run the fridge on 12v. From what a tech at our T@B dealer said, it draws about 11amps, the alternator on our XC90 puts out about 7-8amps via the 7 pin outlet, and the converter in the T@B clearly doesn't keep up with it.

Although now I'm wondering if by running it on 12v for more than 12hrs possibly damaged the converter while plugged into 120v from excessive current draw over 12v. Should the converter be able to run the lights and radio without the battery hooked up?

ericnliz · July 2016

oops!

Verna · July 2016

Yes, the converter will run the lights and radio without a battery. The converter takes the 120v, converts it to 12V for everything on the right side of the converter.

But, since you selected battery for the fridge, the battery had to obey its switch and it used your battery. Sure your battery is compromised, but without a load test, you can't tell how compromised. And since you only did this for a short period of time, maybe you'll be able to get a few more years out of the battery.

The converter should be OK. PXLated rarely uses electricity and his converter is fine. Others never camp without electricity and their converters are fine.

Just be be sure to get a load test on the battery after it has come up to the " normal" voltage you are used to after charging.

Nomad · July 2016

Ouch!
The only time I switch to battery is while on the move and luckily my Jeep has the large alternator that can keep up with it. The first thing I do if/when I stop is switch the fridge off and then once ready to roll or set up, onto propane.

T@Buhura · July 2016

Verna said:

Yes, the converter will run the lights and radio without a battery. The converter takes the 120v, converts it to 12V for everything on the right side of the converter.

But, since you selected battery for the fridge, the battery had to obey its switch and it used your battery. Sure your battery is compromised, but without a load test, you can't tell how compromised. And since you only did this for a short period of time, maybe you'll be able to get a few more years out of the battery.

The converter should be OK. PXLated rarely uses electricity and his converter is fine. Others never camp without electricity and their converters are fine.

Just be be sure to get a load test on the battery after it has come up to the " normal" voltage you are used to after charging.

Yeah, we rarely use 120v. We normally run off solar and sure enough when on the road, out of the few times we've plugged into 120v (3 in total), 2 have resulted in this mishap! Um, so it's not a good sign that none of our 12v accessories like the lights inside, fan, or radio are working while I have the battery out charging. Bummer. But I guess since whenever our T@B is in storage I keep the battery in the garage on a battery maintainer it shouldn't be an issue, only on the rare times we actually plug into 120v.

What's the best way to test the converter? Are there instructions on verifying it's working correctly with a multimeter, or perhaps even resetting it, like pulling the 30amp fuse?

Verna · July 2016

I do not know how to test the converter--honestly. I can tell you if some symptoms point to a bad converter, but I wouldn't be 100% sure unless I was there.

I thought you you were plugged into 129V in the barn. If you have removed your battery from your T@B and you are not plugged into electricity, you will get nothing.

So, tell me what your T@B has plugged into it right now. Battery not connected to T@B wiring? No 120V plugged into T@B?

T@Buhura · July 2016

Verna said:

I do not know how to test the converter--honestly. I can tell you if some symptoms point to a bad converter, but I wouldn't be 100% sure unless I was there.

I thought you you were plugged into 129V in the barn. If you have removed your battery from your T@B and you are not plugged into electricity, you will get nothing.

So, tell me what your T@B has plugged into it right now. Battery not connected to T@B wiring? No 120V plugged into T@B?

I'm plugged into 120v in the barn with the battery disconnected. The battery is on the floor next to the T@B with a charger directly to it while the T@B is getting a healthy dose of 15amps at 120v. The fridge is running on 120v currently, but none of the 12v accessories seem to be getting any power. Reminds me of when we first picked up our T@B and it turned out was a bad converter that required for the battery to be good and connected to deliver 12v. I guess I'll start by checking the fuses. I'd be really bummed if running the fridge on 12v overnight would have killed the converter and the battery. These converters very temperamental and not very robust.

Ratkity · July 2016

Ok, I might have this totally wrong (well, more than just "might"), but that said, I thought it was necessary to have a battery connected for all 12v appliances to work even when connected to 110v. The converter takes 110v and goes to the battery (with built-in charger) and the rest of the 12v appliances run from the battery - thus the battery is sort of a buffer for "low voltage" situations. All 110v outlets will work without the battery. Even when on 30A service, the overheat light will flicker a moment when the water pump is on - I'm assuming it's because of a temporary load pull through the battery.

I probably have this all backwards! Where's that schematic?

Nomad · July 2016

I think you got it right.

ChanW · July 2016

I'm pretty sure that the battery is simply another 12V 'load' for the converter, along with all the other 12V accessories.

The 12V accessories should operate with or without the battery installed.

ChanW · July 2016

'uhura, it makes sense that your battery was dead, because it was the only source of 12V power. I'm guessing that your converter wasn't putting out 12V, period.

Definitely, check the fuses!

Curiouser and curiouser...

T@Buhura · July 2016

ChanW said:

'uhura, it makes sense that your battery was dead, because it was the only source of 12V power. I'm guessing that your converter wasn't putting out 12V, period.

Definitely, check the fuses!

Curiouser and curiouser...

Ok! Some good news - I just left a nearby NAPA and they load tested to confirm its still good for its rated 550CCA and it passed. Sure enough though before I took it inside I checked it's voltage and it was still holding 12.8v after the 30+min drive to NAPA which was a first good sign it will still hold its charge. It is very curious that I read 0.2v when I checked it yesterday morning. And that the onboard volt meter was totally dark (not enough juice to even power it for any reading).

Will definitly check all of the fuses as soon as I get back to the T@B.

ericnliz · July 2016

Good luck, and let us know how it turns out please.

ScottG · July 2016

As Verna noted previously, the battery does not have to be connected for the 12v devices to work while hooked up to shore power. (Yes, I've done it.) The 120v supply powers the converter, which in turn powers the 12v devices and charges the battery as needed.

Unless the fridge is wired up different from everything else, in theory it should be able to run on DC from the converter. However, T@Buhura's experience suggests that the converter can't keep up with the high power draw of the DC fridge (~10 amps?), so the battery is drawn down in an effort to keep up. Just guessing here...but I think it's a reasonable guess. I'm less sure of if or why the converter would be damaged in the process.

I'm curious though. T@Buhura, please update when you get it sorted out. Good luck!

EDIT: I mean, "Yeah, what Chan said!" :-)

ScottG · July 2016

A little more info...

The converter in my 2015-S (WFCO WF-8735P) is rated for a maximum output of 35 amps, with no single circuit rated for less than 20 amps. Again, in theory, more than enough to run the fridge in DC mode using the converter without depleting the battery. (Not that you would choose to do this if shore power were available, but we are talking about accidentally putting the switch on the wrong setting...)

@T@Buhura, I know you have an older T@B, and probably a different model converter and fridge, but this should give you a ballpark. If I understand your experience correctly, it makes me think a faulty converter (or shore power supply) was the root of your problem. Hopefully your battery weathered the storm ok.

T@Buhura · July 2016

ScottG said:

A little more info...

The converter in my 2015-S (WFCO WF-8735P) is rated for a maximum output of 35 amps, with no single circuit rated for less than 20 amps. Again, in theory, more than enough to run the fridge in DC mode using the converter without depleting the battery. (Not that you would choose to do this if shore power were available, but we are talking about accidentally putting the switch on the wrong setting...)

@T@Buhura, I know you have an older T@B, and probably a different model converter and fridge, but this should give you a ballpark. If I understand your experience correctly, it makes me think a faulty converter (or shore power supply) was the root of your problem. Hopefully your battery weathered the storm ok.

Hi Scott,

I checked mine again this morning (I have the WFCO WF-8725P which I assume is the 25amp model along with the NORCOLD 3 Way Fridge - I think it's the 3163 model series) and before I plugged the battery back into our T@B, I thought I'd test the leads for it to see if there was any voltage coming out (reverse battery) and totally null (0v). I had already checked the fuses last night and they're all fine, including the 30amp reverse battery fuse which I assume is what allows the converter to maintain/charge the battery. The other 4 fuses (15amps) were also fine. Sure enough, as soon as I plugged our trusty battery back in - back from the dead (0.2v reading just a couple of days ago) all 12v accessories and lights came to life.

With the battery plugged in again, I tried resetting the 30amp fuse and noticed that this time it sparked a little when I reconnected which was good to see - seems there's voltage flowing through and the converter fan powered up momentarily. Does this mean it's reset and providing 12v out? I don't recall the reset procedure.

ericnliz · July 2016

T@Buhura, Glad to hear you got your problem solved. Sounds like that was a real head scratcher! Keep us posted please.

ScottG · July 2016

T@Buhura said:

Hi Scott,

I checked mine again this morning (I have the WFCO WF-8725P which I assume is the 25amp model along with the NORCOLD 3 Way Fridge - I think it's the 3163 model series) and before I plugged the battery back into our T@B, I thought I'd test the leads for it to see if there was any voltage coming out (reverse battery) and totally null (0v). I had already checked the fuses last night and they're all fine, including the 30amp reverse battery fuse which I assume is what allows the converter to maintain/charge the battery.
...

Sounds like we have similar equipment. On my converter, there is a 30 amp fuse in the second slot from the bottom. This is the circuit that runs to the battery--it allows the converter to maintain and charge the battery (when on shore power), as well as bringing battery power into the camper (when not on shore power).

The "reverse battery" fuse is something different. On mine it's 40 amps and in the lowest slot. According to the manual, this is only there to protect the converter in the event that you accidentally hook up your battery backwards. I'm not sure how it's actually wired in the converter, or if/how it affects operation under normal conditions.

T@Buhura said:
...

The other 4 fuses (15amps) were also fine. Sure enough, as soon as I plugged our trusty battery back in - back from the dead (0.2v reading just a couple of days ago) all 12v accessories and lights came to life.

With the battery plugged in again, I tried resetting the 30amp fuse and noticed that this time it sparked a little when I reconnected which was good to see - seems there's voltage flowing through and the converter fan powered up momentarily. Does this mean it's reset and providing 12v out? I don't recall the reset procedure.

It sounds like you were able to get 12 volt power from your battery, so clearly the distribution side of the converter is ok. What happens when you plug into shore power? If all is working fine, you should see ~13.6 volts coming out of the converter, and you should still have that voltage even if you disconnect the battery. If that doesn't happen, I would suspect a problem with the 120V side of the converter (or with the shore power supply).

If everything checks out, I suppose it's possible something got reset along the way. My converter has a current limiting feature that automatically shuts down in the event of an overload or short circuit, then returns to normal once the problem is corrected. Doesn't seem like that should apply in your case, but I don't really know. Once we start talking about the mysteries inside the box we are getting a little out of my pay grade. :-)

T@Buhura · August 2016

ScottG said:

Sounds like we have similar equipment. On my converter, there is a 30 amp fuse in the second slot from the bottom. This is the circuit that runs to the battery--it allows the converter to maintain and charge the battery (when on shore power), as well as bringing battery power into the camper (when not on shore power).

The "reverse battery" fuse is something different. On mine it's 40 amps and in the lowest slot. According to the manual, this is only there to protect the converter in the event that you accidentally hook up your battery backwards. I'm not sure how it's actually wired in the converter, or if/how it affects operation under normal conditions.

I don't have the extra fuse above the bottom one (reverse battery).

More testing an after just getting back from a weekend side trip to AirVenture. I plugged into shore last night with the battery voltage reading 12.8v and this morning it's at 12.6v. I did have the fridge running on 120v (triple checked it

). I unplugged the battery and set it in the garage on a BatteryMinder to bring it back up and the converter isn't doing its converting to provide 12v to the fan, lights or radio.

This is now the 2nd one in a little more than a year to fail on 12v. This seems to have been bothered by having left the fridge running on 12v accidentally while plugged into shore. Could it have just run hot and burnt out? How reliable/robust are these?

Are there better ones?

ChanW · August 2016

Well, it does have a fan that operates when the 12V output is heavy -- ie, with ours the fan comes on when initially charging a low battery, but shuts off when the battery is trickle charging. Our fan also comes on when the converter is powering the 3-way in 12V mode.

So that suggests that the thing needs cooling w/ high power demands.

Is your converter's cooling fan working properly?

Ugh - I did it again! :o

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