Electrical Woes

[Richard Jansen]

Hey All. Having some power issues. Stored battery in my basement all winter. Plugged trailer into shore power and reinstalled the battery in May/June. Everything worked, I leave it on shore power at home for the remainder of the season to maintain the battery. Went camping 2 weeks ago, everything worked, on shore power the entire time. Went in the trailer the other day, nothing DC worked, battery was also dead, should have been charging. Volt metered everything, had no DC leaving the converter. In the process of messing around and reinstalling the converter something on it sparked and it started proper DC output again. All fuses are ok. voltage across specific circuits varies, ceiling lights were reading 11.2. Battery cables were reading 13.68 (i removed the battery to charge it separately - only reached 90% after almost 24h). With the battery removed and all lights turned on the stereo shuts off, fridge shows fault, CO detector blinks indicating low power. If I understand correctly, my converter stopped working for some reason, therefore my battery drained itself keeping everything else on. The DC system needs both the converter and the battery to run everything at once. With my converter now working and the battery charged will I be ok? Or is there an issue somewhere I need to keep looking for?
Thanks

[NJKris]

The DC system needs both the converter and the battery to run everything at once.

I don't understand this. Even without a battery the converter should power all your DC circuits.

[D W]

The fact that you had a "spark" indicates a fault of some kind. Either a loose wire, or a short. You need to revisit your converter connections, both AC and DC.

[Richard Jansen]

Originally Posted by D W

The fact that you had a "spark" indicates a fault of some kind. Either a loose wire, or a short. You need to revisit your converter connections, both AC and DC.

no power output before spark, full output after, have checked several times

[Richard Jansen]

Originally Posted by NJKris

I don't understand this. Even without a battery the converter should power all your DC circuits.

if i understand correctly the converter doesn't put out enough energy to run everything at once and draws from the battery to fully run everything, then recharges the battery when draw is low

[NJKris]

Mine is a 35 amp converter. My understanding is, it prioritizes DC loads, and whatever is left over goes to charging unit.

[CHICKDOE]

You listed several things but I would ask for one more piece of information. When you got the 13.6 volt reading where did you measure it? At the converter or at the battery terminals? This may make a difference! If at the battery terminals this would indicate that the converter is actually sending power to the batteries which is what you want. If the batteries are not seeing this voltage it could indicate a problem with the converter or a problem in the cables between the converter and the batteries.

From what you say it sure sounds as if the converter was not charging the batteries and the batteries went dead.

The spark seems to imply that it came from the converter but I do not know this. If it did that might point to a problem in the wiring. But don’t take this as gospel.

Also I have always wondered how the converter chooses the proper voltage to operate at based on the state of the battery. I have had a conversation with rep at a company that makes battery chargers and it is now my understanding that the charger does not sit there sending out a constant recharging voltage. Instead it periodically stops the output charging voltage and goes into a query mode where it senses the state of the battery. Based upon this interrogation it then chooses which recharge mode it should be in and restarts the charging process. This whole sensing pause only takes a second or less. I do not know that this is factual or not! It is just my understanding.

I have also heard that some chargers will not recharge a dead battery. A problem in the cables would look like a dead battery to the charger.

Also standard chargers have do way to prioritize loads over recharging the batteries. There is only one set of cables leaving the charger. You would need some form of intelligent device after the charger that could route the output power.

I’m not sure how much of a load you had on a 35 watt charge with all the 12 volt loads on and the fleas batteries. If it exceeded the 35 watt capacity of the converter you may have caused it to shutdown. But I would expect that to blow fuses which should not auto correct.

Turn everything off and measure voltage at the converter output terminals and at the battery terminals to get an idea of what is going on.

[Richard Jansen]

Hi CHICKDOE.
I measured 13.6 leaving the converter, at the battery connections (with no battery installed), and across several fuse locations without the fuses installed. I got different readings on a few of the fuse locations, like the ceiling lights were down to 11.2. Also, when I turned everything on (still with no battery installed, the same scenario where things stopped working properly) output from the converter dropped to 7.5.

The spark came from inside the actual converter circuit board somewhere, I had a neighbour electrician pull it to do testing when it wasn't producing at all, and it sparked when i moved it to reinstall, which somehow turned it on again...

Just read in the manual that it has an electronic current limiter to prevent overload or short-cirucuit conditions. And it automatically returns to normal operation after conditions are corrected. I wonder if I may have done this somehow and the spark was caused by the unit turning back on?

As for battery chargers, the one on my convertor does pretty much what you said, 3 different modes based on what is needed for the system and the battery to keep it maintained and charged adequately. I have a WFCO WF8955PEC, and the manual actually describes these 3 modes nicely.

I actually found a troubleshooting chart on WFCO website for my model that I will use to test/diagnose the unit tomorrow.

Thanks for your help

[Richard Jansen]

Converter is fried based on following procedures on WFCO's troubleshooting chart.