Battery connectors popped off terminals

[Knudsvig]

Tonight we heard a loud pop by battery compartment, smelled a burning smell and opened battery compartment. We found one battery with some smoke coming out and connectors had popped off terminals. Any advice? 1997 excella 30'

[CRH]

I don't see how they popped off.

[J. Morgan]

They burned off.

I’m thinking none of the 12v works right?

Either way, if I was you I would unhook the other battery in case there is a dead short somewhere.

Turn off the inverter and the charger too.

[OTRA15]

Unplug from shore power ASAP if you have not done so already. Disconnect all remaining wires from the battery terminals.

Did your batteries run out of water and get overcharged?

Please post more details, including status of shore power before the incident, age and condition of batteries, and whether you know what the water levels were.

Thanks,

Peter

[Knudsvig]

Originally Posted by J. Morgan

I’m thinking none of the 12v works right?

Either way, if I was you I would unhook the other battery in case there is a dead short somewhere.

No the 12v and everything still was working fine. We were hooked up to 110 30 amp service at the time. When we turned off converter, the 110 was fine but the 12v lights were dim.

Originally Posted by J. Morgan

I’m thinking none of the 12v works right?

Either way, if I was you I would unhook the other battery in case there is a dead short somewhere.

Where is inverter? We turned off converter.

[Knudsvig]

Originally Posted by OTRA15

Unplug from shore power ASAP if you have not done so already. Disconnect all remaining wires from the battery terminals.

Did your batteries run out of water and get overcharged?

Please post more details, including status of shore power before the incident, age and condition of batteries, and whether you know what the water levels were.

Thanks,

Peter

We were hooked up to shore power. No idea of water levels. Batteries seem newer but we've only owned it for 2.5 years. We've never checked water levels. Only one battery affected. The connectors are not attached to terminals. We turned off all power to trailer.

[OTRA15]

You should read the owner's manual in order to understand all the systems and terminology. There should be some info on checking the water levels in the batteries. If you have not done that in over 2 years, you probably fried one battery, and the other battery is likely compromised IMO. If you do not have a printed manual, please advise and one can be located online.

Here is a good general source on RV batteries:

http://www.batteriesnorthwest.com/batteryschool.cfm

Your 1997 AS may not have an inverter, see what the manual says.

I would advise having an RV mechanic or electrician diagnose your electrical system. You might want to buy two new batteries first, in order to get all the systems online when this diagnosis is done.

Others here, more expert than me, may be able to walk you through a step-by-step process of diagnosing things, but given your failure to check the battery water for 2+ years, I would advise against a DIY solution here. You have have narrowly missed a much more serious situation, with a modicum of good luck IMO.

Good luck!

Peter

PS -- In addition to new batteries, you should also replace the OEM converter/charger, assuming it is a single-stage unit. The newer multi-stage chargers/converters will protect you from overcharging your new batteries.

[uncle_bob]

Hi

What you describe is a pretty typical "cell short" in one battery. That drops the voltage of that battery down by about 2V. The energy from the other battery in parallel dumps into the defective one. This adds to the current from the charger. All that current rapidly heats the battery up. You have seen the result. There is no magic charger that will prevent a shorted cell battery from having this rather exciting problem. Shorted cells are one common way that batteries die. Running them in parallel is what makes us "notice" the fact that they have died this way. In a typical automotive single battery setup, you would not have the same excitement.

The answer right now is to replace both batteries. One of them is (obviously) dead. The other one didn't get any better from the event. You need to have both batteries in the set same / same or you will simply destroy the newer battery very quickly.

You will spend a bit of money on the new batteries. Don't go cheap, get good ones. AGM's are a better bet than flooded cells. The Lifelines that AS uses are pretty good. Swapping out the converter at the same time is fine. It may give you an extra year on your new batteries. It also might put 10% more energy into them.

If any of this does not make sense, head over to an RV shop and let them sort it out.

Bob

[J. Morgan]

My experience with AGM batteries is twice the money for the same lifespan, especially if subjected to a accidental discharge or two. (It happens)

Your experience may vary, but that is my take. Buy flooded batteries, the sting is half as intense when they go bad.

A point, never ever have I heard of battery terminals popping off a battery because of a short, but I have seen a three battery bank start a hell of a fire when the main cable became shorted.

[uncle_bob]

Originally Posted by J. Morgan

My experience with AGM batteries is twice the money for the same lifespan, especially if subjected to a accidental discharge or two. (It happens)

Your experience may vary, but that is my take. Buy flooded batteries, the sting is half as intense when they go bad.

Hi

For most people the AGM's last about 50% longer.

Bob

Originally Posted by J. Morgan

A point, never ever have I heard of battery terminals popping off a battery because of a short, but I have seen a three battery bank start a hell of a fire when the main cable became shorted.

Hi

The pop out is a function of heat on the case. The sort generates a lot of heat.

Bob

Originally Posted by J. Morgan

They burned off.

Hi

Actually the terminals pushed out.

Bob

[xrvr]

Originally Posted by Knudsvig

We were hooked up to shore power. No idea of water levels. Batteries seem newer but we've only owned it for 2.5 years. We've never checked water levels. Only one battery affected. The connectors are not attached to terminals. We turned off all power to trailer.

Water levels should be checked periodically no matter what kind of converter you have.

[J. Morgan]

Originally Posted by uncle_bob

Hi



The pop out is a function of heat on the case. The sort generates a lot of heat.



Bob

I would like to see a photo of that.

Originally Posted by uncle_bob

Hi



For most people the AGM's last about 50% longer.



Bob

Which costing twice as much or more up front would make them pretty much an even money investment up front, with twice the time to be accidentally discharged and ruined.

Once there was a time when I really wanted AGMs to be worth my money, but they just weren’t.

[uncle_bob]

Originally Posted by J. Morgan

I would like to see a photo of that.

Hi

I've seen it happen. No photos though.

Bob

[uncle_bob]

Originally Posted by J. Morgan

Which costing twice as much or more up front would make them pretty much an even money investment up front, with twice the time to be accidentally discharged and ruined.

Once there was a time when I really wanted AGMs to be worth my money, but they just weren’t.

Hi

Toss in lower maintenance and less likelihood of random failure. Most AGM's also give you a bit more capacity.

Bob

[uncle_bob]

Originally Posted by avionstream

Water levels should be checked periodically no matter what kind of converter you have.

Hi

They also should be checked pretty regularly if you simply have them sitting in a hot / dry climate. Big black battery boxes out in the noontime sun ... yikes ....

The bigger issue is a "cascade failure". The water going down a bit is ok if the plates are still immersed. It's not *good*, but it's not disaster. Once it gets past the top of the plates, that cell looses capacity. It will be over charged and over discharged relative to (possibly) full cells elsewhere in the battery. That over charge / over discharge heats things up. More water is driven off. The problem gets worse. Past a certain point the high current density is likely to short the cell. Next you have a major mess ....

Most modern batteries have "gizmos" in them to reduce water loss. How well they work is highly debatable. When they work to varying degrees, you get unequal water loss. What's in (or not in) your specific batteries is very much a "that depends" sort of thing. In some cases the batteries sold in the hot / dry part of the country are done a bit different than those sold in the cold / wet part of the country. Those sort of distinctions may flow down to your local retail outlet. They don't flow into something like an RV assembly line.

Lots of variables.

Bob

[J. Morgan]

Originally Posted by uncle_bob

Hi



I've seen it happen. No photos though.



Bob

I could see a hydrogen explosion in a cell ballooning the case and pushing the terminals off the posts if they were not tight, but I would expect to see the caps for the cells blown off too.

[uncle_bob]

Originally Posted by J. Morgan

I could see a hydrogen explosion in a cell ballooning the case and pushing the terminals off the posts if they were not tight, but I would expect to see the caps for the cells blown off too.

Hi

If you conduct the experiment (as I unfortunately have ...) the shorted cell pushes out a lot of acid steam. I doubt that there can be much of a hydrogen accumulation with that "wind" blowing through the area.

The whole thing is current limited mostly by the (very short) cable between the batteries and how clean the connections to the battery are. Either the wire gets hot or the terminals do. Hot terminals melt out of the battery case.

A hydrogen explosion is a different event. The top of the battery compartment is unlikely to be happy with the process. You also will get a sharp report (gunshot / firecracker) noise as part of the process. One way or the other, it will get noticed.

Lots of fun !!

Bob

[AtomicNo13]

During heavy winching, I had a post on an Optima battery melt and blow out if the case. It caused a big dead short!

[J. Morgan]

Originally Posted by uncle_bob

Hi



If you conduct the experiment (as I unfortunately have ...) the shorted cell pushes out a lot of acid steam. I doubt that there can be much of a hydrogen accumulation with that "wind" blowing through the area.



The whole thing is current limited mostly by the (very short) cable between the batteries and how clean the connections to the battery are. Either the wire gets hot or the terminals do. Hot terminals melt out of the battery case.



A hydrogen explosion is a different event. The top of the battery compartment is unlikely to be happy with the process. You also will get a sharp report (gunshot / firecracker) noise as part of the process. One way or the other, it will get noticed.



Lots of fun !!



Bob

If a cell in a battery is down on water, enough hydrogen can accumulate within the cell for a small explosion to occur.

Like I say, that is the only way I can see battery terminals being removed from a battery by a shorted battery unless the terminals melted/burned off. (See my first post to this thread).

[uncle_bob]

Originally Posted by J. Morgan

If a cell in a battery is down on water, enough hydrogen can accumulate within the cell for a small explosion to occur.

Like I say, that is the only way I can see battery terminals being removed from a battery by a shorted battery unless the terminals melted/burned off. (See my first post to this thread).

Hi

Hydrogen can accumulate, but it is very tough to do. The battery is mounted in a way that the gas quickly rises out of the cell. You need a very specific combination of air / hydrogen and spark for an explosion. The cells short normally in a "wet" area. The short is from the plating process that is part of charging. Wet is not good if you are trying to create a spark. When a battery does go boom, things fly around. The terminals are not the big deal in this case ....

Bob