Converter fan keeps running?

[doonkin]

Hey, so I got all these little worrisome things happening pre trip.

My converter fan keeps running on shore power. It was going up and down but now it’s just on low. When I unplug and go just battery- it says fine at 12.8.

2 things-
1. it was a crazy hot day today (dunno if that factors in-prob not)

2. I got tires replaced 2.5 days ago and forgot to plug in when I got home.

I didn’t turn anything on in that time- but guess there’s always a trickle.

I’m testing battery w the 12v cigarette lighter thing in the trailer as I can’t find my damn voltage reader to test at battery.

Any thoughts- thx in advance

[norty1]

If your rig is closed up it could be just a lack of circulation. Do you have any extra demands on the 12v systems that could generate extra heat in the converter?

[Learjet]

Also, check water level in batteries, if you can and have serviceable batteries.

[FPM III]

Your User Profile About Me says you own a 2015 Jayco 23mbh. When you plug in to shore power, does the converter's fan always run 24/7 since you've owned it, or is this a new development?

Many converters cycle on and off, but some brands, like the Todd Engineering converter in my 2000 Jayco Eagle TT have a variable speed fan that runs continuously when on shore power. Therefore, what you're experiencing could be perfectly normal. On my converter, I can hear the fan suddenly increase in speed whenever something, like the water pump starts up, putting a high demand on the battery. As soon as the pump shuts off, the fan slows.

To confirm: Check the converter's user guide or check its manufacturer's website. If you don't have the user manual, you might be able to download one there for future reference.

[craigav]

In addition to what FPM III shared, the WFCO converters (the ones I have read the manual for and likely all of them), control the fan speed based on the output current. The more power output the higher the fan speed. Interesting to note that temperature is not what the fan speed is based on, only the output current. What this means is with the WFCO converters that if the fan is on high and stays on high, that for one reason or another the converter is outputting current at a high level. This would be common with a low battery(s) but if it stayed that way for a very long period of time (more than what should be needed to bring the battery(s) to full charge) then I would suggest to make an effort to determine why the converter is under a heavy load for an extended period of time.

As stated in FPM III's comment, check the user guide for your specific converter make\model.

~CA

[norty1]

But correct me if I am wrong, Does not the conversion process and the amount of current required to convert create heat?

[doonkin]

So yesterday fan was running like gangbusters cycling up n down.

I check the water in battery-fine.

This morning I put on all the 12v lights to give some load- quiet as a mouse.

I think, maybe?, because I had it on battery only for the last 3 days in very hot temps the converter was charging up the battery n working harder-would that be a possibility?

Anyways, it’s not happening now. My electricity skills are zero but I hope that was it.

[norty1]

So you are thinking the batteries were recharging? I would do some checking with a voltmeter to determine if the batteries are now fully charged and if the charging voltage is applied when the converter is charging them.

[craigav]

Originally Posted by norty1

But correct me if I am wrong, Does not the conversion process and the amount of current required to convert create heat?

Yes, that is correct. This understanding is why some converters (not sure which ones but for sure WFCO) adjust the cooling fan speed based on the current output instead of the converter's temperature. Being that the fan speed is based on the current, this allows the fan to turn on before the converter is very hot. In other words, it allows the cooling fan to be proactive vs reactive. ~CA

[FPM III]

Originally Posted by doonkin

...This morning I put on all the 12v lights to give some load- quiet as a mouse...

There is nothing that can be derived from this vague statement. What constitutes "all"? There are just too many variables. How many lights? Are they a mix of light types (incandescent/fluorescent/LED) or all one type? LED lights require so little power compared to the other types it's possible that the load on the battery could be minimal enough that just a trickle charge could sufficiently keep the battery fully charged.

If everything that runs on 12V DC in your TT is operating OK, the battery is maintaining its charge while plugged into shore power, no signs of problems with the converter other than the cooling fan is changing pitch (which, to me, appears to be normal), I have to think the converter's doing its job of keeping the battery charged and there's nothing to be concerned about.

[doonkin]

Thankyou guys.

Sorry for freaking out. There was a ton of little things went iffy this week.
I will take all this great info into account and keep a. Eye on it.

I read on another forum about turning on everything 12v (lights/fans water pump) but I guess that’s not a great test.

I think everything’s fine n if not a new battery is in order

[skids]

Mine has been running since we returned from a camping trip yesterday. The batteries are 2019's and I noticed that the trailer jack seemed to be straining when removing the spring bars. I suspect that they are just not charging like a new set of batteries. I always heard that batteries have resistance and I think that the converter induces more current when the resistance is lower (weak battery). Does anyone know how to load test batteries without a load-testing device? For example, can you run the awning motor while testing battery voltage, and is so what should it be?

[craigav]

Originally Posted by skids

Mine has been running since we returned from a camping trip yesterday. The batteries are 2019's and I noticed that the trailer jack seemed to be straining when removing the spring bars. I suspect that they are just not charging like a new set of batteries. I always heard that batteries have resistance and I think that the converter induces more current when the resistance is lower (weak battery). Does anyone know how to load test batteries without a load-testing device? For example, can you run the awning motor while testing battery voltage, and is so what should it be?

Only under extreme scenarios can you determine a battery is bad when using a light load such as the awning motor. So for the most part the answer is no but with a caveat if you knew for sure the battery has been charging for many hours and the battery charger indicates the battery is fully charged, and then you use a low amp (relatively speaking) device such as the awning motor and the voltage at the battery drops quickly below 10.5 volts then that would indicate a bad battery.

You need at minimum for a more reliable test a clamp style ammeter as in the image. If not this one be sure the one you purchase (if you don't already have one) specifies that it can measure DC amperage.

While it is common to test a battery with a known load (amperage) and see how long the battery can maintain above 10.5 volts, it is also possible to get a fairly accurate understanding while charging. For example, if your converter is putting out 20 amps to the battery, and continues to do so for a longer period than it should, then that would also indicate a bad battery. To be more specific, if your battery is a 100ah battery and if it is completely dead, and you recharge it at 20 amps, then at 5~6 hours it should be fully charged or very close to it (5hr X 20 amp= 100ah) but if it continues on much longer (hours) then that would also indicate a bad battery. You have to use a meter though like this or similar to know how much current is going to (or from) the battery and you can't test this at the converter as the current could be going somewhere other than the battery and you need to know the current that is going only to the battery.

I will also add that the method I mentioned also has issues which is why it isn't often used, the issue is that most battery chargers (converter for example or dedicated charger) constantly reduces the charge current as the voltage rises and therefore the math is very hard to do as the current tapers off and continues to drop. This type of test is more specific to if the charge current is measurably higher than the battery rating, for example if your converter fan stays on and that current is going to the battery (verified with an ammeter) and you can determine it has been doing that for a period longer than the battery rating. Ex if the charging current is longer or vastly exceeds 20A x 5 hrs, or 10A x 10 hrs, or 5A x 20 hrs, etc. for a 100ah battery. ~CA

BTW, for completeness, a battery can also be bad if it doesn't take any charge current or very much. However my above comments were based on the understanding that the charge current is likely at a higher level as the converter fan running constantly would indicate. (unless you have something else pulling current such as a forgotten inverter left on or similar).

[skids]

Thanks craigav. The good news is that I found the emergency disconnect cable pulled. Like an idiot, I pinched the cable between 2x6's while putting down the tongue jack and it activated the brakes. Thank you whoever that was that suggested that brake cable being pulled.

[jimmoore13]

This may not help much.

I notice the converter fan running when on shore power or generator when:

• There are 12-volt loads of any significance;
• There are 120 volt loads of any significance;
• When the batteries are not fully charged.

Perhaps this is a tip-off that something is runnign that you are not aware of. I'm going to assume your 2015 Jayco 23mbh has an absorption fridge. If the fridge is on auto and you are connected to shore power or generator, the fridge functions using an electric heating element. Is your fridge running on shore power?

A simple test of this hypothesis. Make sure your propane is on, then go to the fridge and select "gas" instead of "auto" (or whatever the labels say on your fridge). Leave the fridge doors open to ensure there's a demand for "cold." Give things a moment. You should hear the gas heater on the fridge ignite. It's kind of subtle, but you should be able to hear it. Meanwhile, what happened to your converter fan? If the fridge was the load on the converter, one would expect the converter fan to slow or shut off once you switch to propane.

I raise this possibility, because some loads are easy to overlook. Earlier this year we were connected to shore power and popped the breaker on the power pedestal. We were running the AC, and we were careful to not use other major loads (microwave, counter-top appliances, etc.) so we wouldn't overload the circuit. But I forgot that we had turned on the electric side of the hot water heater. I scatched my head for about 10 minutes before I figured out that the electric hot water heater probably started while the AC was in full-on cooling mode. I also had the fridge on auto...120 volt power.
Breakers can be pretty tolerant of this abuse, but eventually the right combo of loads will trip the breaker.

One other symptom similar to yours. This year we bought Starlink. Right now, we are powering it with a 500 watt pure sine-wave inverter. Starlink Gen-3 uses about 100 watts at 120 volts. And that power was actually sourced from the batteries. Whether on genny or shore power, our converter fan ran continuously...at a slow speed that fluctuated a bit...when Starlink was on. This was true even though we have 400 watts of solar on the roof and 200 watts of suitcase solar on the ground...more than enough to keep up with Starlink for a good part of the day.

So my hunch is that "something" is running. That something can be either 120 volts (e.g. the hot water heater or fridge) or 12 volts which the converter will supply regardless of battery charge. Parasitic loads aren't enough to trigger the converter fan...unless the battery's state of charge is a bit low.

Those are my guesses. I didn't read all the replies, so I may have missed the resolution to your issue.

[jimmoore13]

Originally Posted by skids

Thanks craigav. The good news is that I found the emergency disconnect cable pulled. Like an idiot, I pinched the cable between 2x6's while putting down the tongue jack and it activated the brakes. Thank you whoever that was that suggested that brake cable being pulled.

I just posted without seeing this. Be sure to test your brakes carefully before you leave on your next trip. This applied the brakes with full force for what I gather was an extended period...overnight or more? Without being an alarmist, this info is, to say the least, alarming.

[craigav]

Originally Posted by skids

Thanks craigav. The good news is that I found the emergency disconnect cable pulled. Like an idiot, I pinched the cable between 2x6's while putting down the tongue jack and it activated the brakes. Thank you whoever that was that suggested that brake cable being pulled.

I would still suggest the clamp style ammeter (if you don't have one) as with it you could easily and quickly determine that the current from the converter was going somewhere other than to the battery. ~CA