Battery Connection Mishap

I have a 2010 Jayco Feather Lite that I haven't used in almost two years. Got it out of storage this weekend, and the house battery was still hooked up and, of course, dead.  Brought the TT home and removed and recharged battery with a standalone charger. Then reinstalled battery backwards. 

At the time, the TT was not hooked up to shore power or a generator, but was hooked to my Expedition (which was not running).  While the battery was connected incorrectly, I ran my electric tongue jack (which ran, unbeknownst to me at the time, in reverse).  Within a few minutes, I realized my mistake and corrected the connection, and called it a day.

The next morning I connected to shore power thru a GFI outlet in my yard, and the GFI kept tripping.  Turned off all breakers except main and converter, and GFI did not trip.  Checked all DC fuses and reverse polarity fuse on converter (iota dsl 45), and all were good.  Per idiot light on TT, battery was fully charged.  All DC items in TT appeared to work fine while connected to shore power.  Left unit connected to shore power for 24+ hours, and disconnected.  Then no DC power in TT.

I am hoping that this is just the matter of a dead battery (from 2 years of neglect), and not a problem caused my reversed connection.  From what I have read, it seems that perhaps the reverse connection would not have cause damage since no AC power source was connected to battery while in reverse connection.

Question:  Is that a reasonable hope? 

There is a whole list of things you may have fried including the control boards for the water heater, refrigerator, air conditioner, possibly tv and stereo if equipped with DC powered models, ...

Isaac-1 said:

There is a whole list of things you may have fried including the control boards for the water heater, refrigerator, air conditioner, possibly tv and stereo if equipped with DC powered models, ...

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Thanks for you quick reply. 

Wouldn't the reverse polarity fuses have prevented that from happening?  I had assumed that was their intended purpose.

The first thing to do is change your battery and then go from there.

Actually the first thing is to have battery tested, after 2 years it is probably junk. 

lynnmor said:

Actually the first thing is to have battery tested, after 2 years it is probably junk.

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I said to CHANGE the battery, not charge.

I crossed the wires in a TT I had about 7 or 8 years ago and the main 30 amp fuse immediately blew. No other damage other than a fuse to the radio which took me a while to track down. Hopefully, battery condition aside, you'll just have to check and replace that main fuse.

The reverse polarity fuses will only protect the converter, not all the DC appliances wired to the battery

Thanks everyone for help and suggestions.

Rene T said:

The first thing to do is change your battery and then go from there.

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Picking up a new battery on the way home from work.

Joezeppy said:

I crossed the wires in a TT I had about 7 or 8 years ago and the main 30 amp fuse immediately blew. No other damage other than a fuse to the radio which took me a while to track down. Hopefully, battery condition aside, you'll just have to check and replace that main fuse.

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Radio works fine.  The breaker l labeled "main" on the distribution panel seems fine.  All the DC fuses on the ditribution panel check out , as do the reverse polarity fuses on the converter.  Not sure where other fuses might be?

Isaac-1 said:

The reverse polarity fuses will only protect the converter, not all the DC appliances wired to the battery

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Wouldn't the DC blade fuses on the distribution panel be tripped if polarity was reversed -- on same principle that trips the reverse polarity fuse on the converter?

The only odd behavior that I have noted thus far, are the dead battery this morning (not really odd given my neglect of this battery) and the tripping of the GFI in my yard when connecting to shore power -- I don't recall this happening in the past -- could stone dead battery cause this?

Gatoruss said:

Radio works fine.  The breaker l labeled "main" on the distribution panel seems fine.  All the DC fuses on the ditribution panel check out , as do the reverse polarity fuses on the converter.  Not sure where other fuses might be?

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IIRC, the main 30A fuse was in the breaker/fuse panel at the top.

Joezeppy said:

IIRC, the main 30A fuse was in the breaker/fuse panel at the top.

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I have a  breaker labeled "main" at the top of the AC side of the ditribution panel.  It seems fine -- wasn't  tripped.

I've read about a lot of rvs that trip GFCIs, but essentially there was nothing wrong with the RV.

>
From what I have read, it seems that perhaps the reverse connection would not have cause damage since no AC power source was connected to battery while in reverse connection.<




While not always the case, most electronic devices come out of the factory with reverse polarity protection standard. You may well get away with this. Sure hope so!

Watching this thread to see what the new battery does for the problem. Hope all turns out well.

Arch Hoagland said:

Watching this thread to see what the new battery does for the problem. Hope all turns out well.

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Me too!?

Due to work, I will not be able to try out a new battery until Saturday morning (plan to grab one on way home from work Friday). 

FYI -- In the meantime, I measured the voltage on the old battery with a DMV, and it read 12.46volts.  I hooked it up to a standalone chager, the voltage across the battery with that charger attached  was ~17volts, and the charger's "Charge Complete" LED came on almost immediately ( although, that happens often with this charger and I'm not certain that that feature works correctly on this charger).  After about an hour on the charger, the reading across the battery with the charger attached was 13.5volts and the voltage across the battery without the charger attached which 13.09volts.

I'm not sure what all that means necessarily, except that perhaps I need both a new battery end a new standalone charger!
?

A fully charged battery at rest should read 12.6V.  A charger with a 17V output is clearly in "bulk charge" mode for very low battery.  That seems high even then.  Normal maintenance charge should be about 13.5V.

The question on the old battery may be how much juice is actually available.  While technically still alive, it may drain down very quickly compared to a new battery.

There are battery load testers that can help. Harbor Freigt has one. I think I paid about $30 for one. Have not used this particular one yet. (Couldn't help myself when at HF!) It will get very warm when in use as it creates heat when applying the load.

I left the battery hooked up to the charger overnight - approx 24 hours.  This morning, the voltage with the battery attached to the charger was 13.4 to 13.5  volts, and the voltage immediately after disconnecting the charger was 13.16 volts.  I hadn't mentioned this previously, but battery water levels looked good (after sitting in Florida sun almost for 2 years)

I just took the battery to an auto parts store that provides free battery testing.  The test results were:

• "Good Battery"
• 12.91 volts
• 770 measures Cold Cranking Amps
• 800 rated Cold Cranking Amps

I plan to grab TT this evening on the way home from work, and see what happens. 

Well -- I hooked battery and had juice to the powered jack.  I was able to raise and lower the tongue, but otherwise no 12volt power in the TT.

It seems that there must be a fuse somewhere that I am missing.  I plan to scour the unit tomorrow.

In case anyone is interested or on the chance it miht prompt any ideas, I have taken and labeled some photos of my battery hook up.

Follow the positive lead from the battery to the trailer. Look for a small rectangle, about 1"x 1/2" x 3/4", that the positive lead hooks to. That's a circuit breaker. It could be hanging out in mid-air, or it could be in a junction box. Being exposed to weather, the connections and breaker often go bad.