Disaster averted, or was it?

[soldiermedic]

I went out to the Airstream tonight to get ready for our first trip out of the season. I plugged the trailer into AC power to get the lights working. This is common for us after a long winter of no charging, as I would think for most anyone.

Anyhow, I went to check my battery disconnect switch, and noticed that when the bed was last converted to a sofa, our manual crank for the powered jack was wedge between the walls and the battery terminals. I quickly unplugged, and removed the jack handle from the battery. Major evidence of arc damage on the battery terminals and on the handle.

After removing the handle, I plugged back in, and worked for awhile. The parallax converter had yet to turn on after around 30 minutes. Getting worried, I pulled the oven to have access to the converter. There were two 30 amp fuses on the side (see pics), and I figured I would see if they were blown. I pulled the top fuse out, and the converter magically turned on. The fuse was fine, but VERY hot. I pulled the second fuse to find it just as hot, and the converter still hummed along like there was no issue.

I am certain that the battery (Optima Gel Cell) was completely drained from the short created, but will it still be able to hold a charge? I just want to get a new battery if charging efforts are futile. Any ideas on what possibly could be wrong with the converter, or is it normal for them to work with these two (Very hot) fuses pulled?

Any thought and comments other than how stupid I was to have the handle in a spot it could get wedge into the battery terminals?

Thanks,

Steve

[Ahzmyrah]

From the looks of the manual crank handle you indeed did have a short from the battery to another part of the trailer as evidenced by the two melted spots that are fairly close together. In other words it wasn't a direct short positive to negative terminal. Also the event was of a fairly short duration. (No pun intended) If the handle was jammed against the positive terminal shorted to ground and held in place for any lenght of time it would have melted more and gotten hot enough to start a fire very quickly. The plastic handle grip would have melted also. This is good news if my detective skills are correct. Because if the short just lasted an instant or it happened twice for small amount of time making a distinct mark each time on the handle. None of the fuses that are designed to protect the electric circuits blew and the battery is in one piece. So I think you should be golden. Most batteries will withstand momentary shorts without damage. It happens all the time thats why circuits are fused to protect them from overloads such as a short. The hot fuses should have been on the DC output side of the converter. The converter will work because it is converting AC to DC. The converter will stop working if you pull the fuse or trip the breaker on the AC side.

[soldiermedic]

Actually, the handle was shorted across both battery terminals, and not against the trailer.

I'm going to leave her plugged in over night and see what will happen.

Steve

[2airishuman]

Originally Posted by soldiermedic

...I am certain that the battery (Optima Gel Cell) was completely drained from the short created, but will it still be able to hold a charge? I just want to get a new battery if charging efforts are futile...

check the battery with a mulitmeter.

IF it's "completely drained" this will be a problem.

my understanding is that the p-lax will NOT charge a fully depleted battery...

there needs to be 9 or 10 volts already, or something in that range.

so the battery needs to be charged by some other method UPTO some base level...

b4 the converter will operate in charge mode.

the p-lax manuals are online for the 73xx and 74xx series.

cheers
2air'