Newbie question: new battery sparks!

[Skwidward]

I changed out the battery on my 19ft Jay flight, but I was too scared to hook it up. I connected the negative terminal, but when I touch the positive lug to the positive terminal of the battery, it sparks.

How am I supposed to bolt this thing up when it's throwing sparks like that?

[mikeauto2]

Just put it on and tighten terminal. Just make sure you are on the correct terminal.

[Cannon]

Somethings on drawing a load. Unplug from shore power and make sure everything in rv is off. How many batteries do you have?

[skids]

On mine, white cable goes to the negative pole. You might consider disconnecting shore power while connecting that. You might also want to pull the 30 amp 12 volt fuse while you connect it to the battery if it bothers you. You can put the fuse back in afterwords - however, I prefer to leave the fuse as-is and connect/disconnect the negative terminal as needed. I always connect the positive first when replacing batteries, negative last.

[Skwidward]

I’m not connected to shore power.

Maybe I’ll try hooking up the positive first and negative last.

I just don’t wanna touch the terminal with it sparking like that with every little movement of the lug.

It’s just one battery 12V 100 ah lithium.

[RAurand]

Originally Posted by Skwidward

I’m not connected to shore power.

Maybe I’ll try hooking up the positive first and negative last.

I just don’t wanna touch the terminal with it sparking like that with every little movement of the lug.

It’s just one battery 12V 100 ah lithium.

Like Skids said above, Are you connecting the white cable to ground ( negative) and black to positive? That is the correct way...

BLACK IS NOT GROUND HERE. WHITE IS.

[Skwidward]

Originally Posted by RAurand

Like Skids said above, Are you connecting the white cable to ground ( negative) and black to positive? That is the correct way...

BLACK IS NOT GROUND HERE. WHITE IS.

No. The wires from the trailer are red and black. They are labeled “positive” (red) and “negative” (black).

I even held the red wire (by the insulated part) so the lug was touching the positive battery terminal and kept it from moving/sparking while my wife lowered the electric awning.

I just didn’t bolt it up, as any movement caused it to spark.

[Mustang65]

As mentioned earlier, pull the 30Amp blade fuse that is on the positive cable heading back to the TT. This will eliminate any loads and there should be no sparking. Then connect the Positive cable.

Don
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RVing with SOLAR

[Skwidward]

Originally Posted by skids

...pull the 30 amp 12 volt fuse while you connect it to the battery if it bothers you. You can put the fuse back in afterwords...

Can you do that without getting shocked?

I mean pull the 30 amp fuse from the 12V panel (the 'red' that goes back to the battery positive) while the battery is unhooked, hook the battery up, then pop the 30 amp blade fuse back in?

[Mustang65]

Originally Posted by Skwidward

Can you do that without getting shocked?

I mean pull the 30 amp fuse from the 12V panel (the 'red' that goes back to the battery positive) while the battery is unhooked, hook the battery up, then pop the 30 amp blade fuse back in?

Don't pull the 30 amp main fuse.
- Put rubber gloves on grab the positive cable on the insulation and hold it over the positive terminal, then pound the cable connector on the battery lug with a piece of wood. This way you are not touching any wire. Yes, there will be a small spark for only a moment. Once you pound the cable connector on the battery terminal, use a wrench to tighten the nut.

Don

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[Mustang65]

If you want to insure that you do not have any sparks in the future, install a Battery cut off switch on the negative or positive side of the battery. This way you can turn the switch off and not see any sparking. The below picture shows the switch on the negative cable.

Don

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RVing with SOLAR

[RogerR]

12 volts will not spark or shock through your body unless you are covered in salt water or some other conductor. Your body is not a very good conductor.

120 volt AC will shock your socks off!

I think you might want a battery cutoff switch. It will also spark when turned on and off but not very much and they are built for that. I prefer mine on the ground (negative) side but others disagree.

A cutoff switch is nice as you can keep your battery from being drained by parasitic loads like the CO/LP monitor.

[Skwidward]

Originally Posted by Mustang65

Don't pull the 30 amp main fuse.
- Put rubber gloves on grab the positive cable on the insulation and hold it over the positive terminal, then pound the cable connector on the battery lug with a piece of wood. This way you are not touching any wire. Yes, there will be a small spark for only a moment. Once you pound the cable connector on the battery terminal, use a wrench to tighten the nut.

Don

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Yeah, I see what you're saying. That works with like regular car batteries, because once that lug has slipped onto the battery terminal, that's it; it's on. You can now tighten it. ...no movement

However, I'm talking about a battle born lithium battery. It doesn't have those kind of lugs. Its lugs are ones that you must put a bolt through then attach a lug and tighten it up bolt and nut style--lots of movement and sparks while that lug is moving around.

https://www.amazon.com/Battle-Born-B.../dp/B07JLVGTW5

I'm pretty sure the sparks are harmless. It's just freaky to touch bare hands to metal in order to thread on a nut while it's throwing sparks at you...

[norty1]

Originally Posted by RogerR

It will also spark when turned on and off but not very much and they are built for that. I prefer mine on the ground (negative) side but others disagree.

Depending on whether you learned your electronics in a Navy school or an Air Force school ! LOL

[Skwidward]

I am absolutely installing a cut off switch. I'm gonna do a whole solar install. Just right now I wanted to provide some shade by opening the awning by temporarily hooking up a battery.

You know what I found weird? There is nothing in in the breaker box of the TT that travels back to the negative terminal of the battery. Everything--the grounds from the AC circuits, the negatives from the DC circuits all connect to chassis ground. The only wire to and from the battery to the TT breaker box is the positive.

Me finding that weird may be my inexperience with TTs, but .....it just seems weird. It seems like the chassis of the TT "IS" now part of the whole circuit..

[Mustang65]

Go to the frame connection for the Battle Born's negative connection.

- Buy a Marine/RV battery disconnect switch (Amazon)
- Buy a 6" black automotive battery cable with a 3/8" lug on each end (AutoZone or Amazon)
- Unbolt the negative cable from the frame
- Connect the new 6" cable to the frame bolt.
- Connect the other end of the new 6" cable to the new battery disconnect switch.
- Turn the switch to the off position
- Mount the new battery disconnect switch to the frame (drill 2 holes in the frame for a sheet metal screw using the switch as a template)
- Connect the Battle Born negative cable to the disconnect switch
- Turn on the switch
- Job done, should take less than 30 minutes with parts.
Don

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RVing with SOLAR

[skids]

If you have big sparks, chances are that you have 12v items switched on in the trailer.

[RoyBraddy]

I would do another look at your new battery. Find the word NEG or the symbol '-' stamped on the battery case and make sure this is the battery terminal going to your frame ground. I've never seen a lot of Sparking like you are describing when just putting on the battery terminals...

Of course OLD SCHOOL always says hookup up the POSITIVE FIRST and FRAME GROUND LAST. This is a safety thing to keep you from accidently touching frame ground when using a wrench to tightened up the POS terminal lug...

Roy Ken

[Marmot]

You already figured it out. The positive goes on first, always.

[Popmechmike]

Always disconnect the negative cable first and reconnect it last. That way, if you accidentally touch the chassis ground with your wrench while connecting the positive, there is no complete circuit and no chance to weld your wrench to the positive post.


You can't get a shock from 12 volts, even if you're standing in a puddle.


And, a few small sparks while making the last connection at the negative terminal is normal unless you have turned everything off that pulls any power. There are too many things that do pull power to count or turn off, so don't worry about it.


Big sparks when making the connection means you have the battery polarity wrong.



Helped a fellow last night troubleshooting his TT--he's wired the socket on the side of his garage at 220V instead of 120. There were actual sparks coming out of the converter when he turned on the breaker. Good-bye converter. Amazingly, the A/C unit worked fine for an hour or so on 220, and continues to work now that we've rewired to 120.


Don't take anything for granted.