How to mess with batteries without sparks?

[glocklt4]

I have read through the manual for my 200 sport lately while I'm adding a second battery. There are all kinds of warnings about sparks from batteries in a boat due to gas vapor build up. Since I smell a bit of the normal gas vapor around the engine since getting my boat, and the bilge blower is there to vent vapor for this purpose, it is understandable that it is more dangerous than working on a battery of a car.

So with this in mind, how are you supposed to hook up a battery after disconnecting it without a spark? I don't remember seeing one when i hooked the neg cable back up to my battery a month ago while de-winterizing, but I'm not sure that there wasn't one. Usually when working on cars, it's a big spark. Don't want to blow up the boat!

 

[rondds]

If you connect the POS terminal first, then connect the NEG you'll get little to no spark. This is what I've always done. Hopefully no one will tell us that I've been doing something wrong all these years (?)

 

[1stSeaRay]

The spark is created when electricity jumps the gap between the terminal and the wire. If there is no electrical load, there shouldn't be a spark.

Make sure your battery switch is OFF before making or breaking the connection. Also check that there are no loads that connect directly to the battery (bilge pump, radio memory, etc)

 

[chris41483]

Ron, I am curious as to why you think it makes a difference which terminal you connect first. Either way you are simply completing a circuit.

I am not trying to argue, just genuinely interested as to why you think that, and if you may know something I do not.

 

[glocklt4]

Ron, I am curious as to why you think it makes a difference which terminal you connect first. Either way you are simply completing a circuit.

I am not trying to argue, just genuinely interested as to why you think that, and if you may know something I do not.

Yeah, my thoughts as well.

 

[glocklt4]

The spark is created when electricity jumps the gap between the terminal and the wire. If there is no electrical load, there shouldn't be a spark.

Make sure your battery switch is OFF before making or breaking the connection. Also check that there are no loads that connect directly to the battery (bilge pump, radio memory, etc)

Correct, if you have a battery switch (that is ignition protected) in the off position and connect it, then turn the battery switch on, you shouldn't ever get a spark. My boat didn't come with a battery switch from the factory. I'm adding one now though.

 

[Redhook98]

If you connect the POS terminal first, then connect the NEG you'll get little to no spark. This is what I've always done. Hopefully no one will tell us that I've been doing something wrong all these years (?)

This is the same way I have done it through the years and have never had an issue. Little to no spark.

Although you are completing a circuit either way you hook it up, it does seem to make a difference. Also, do it quick, The quicker you make or remove contact, the least chance for a spark. Even with a load.

 

[Lazy Daze]

When you're accessing the batteries you are, in essence, working in an open area. It is no longer a closed environment as you have the engine hatch open. If you're worried, just let it air out for a few minutes. Obviously if you strongly smell gas, you might want to figure out why before you did anything else. But you really should never have a strong smell of gas. Other than that, don't worry.

 

[Kurt]

The reason why you connect the negative last is because,

Once the positive and negative are connected the battery is electrically connected to the engine of the boat. If you accidently hit something metal while wrenching the negative terminal down nothing happens. But if you hit metal while wrenching the positive down after the negative is connected the wrench becomes an "arc welder". This of coarse is much more prevalent under a car hood where everything metal is negatively charged when attached.

I agree with the last post, use some common sense and let the engine compartment door open for a while before working with the electrical system. If you smell gas you probably should take care of that problem first.

 

[chris41483]

Kurt, I think we both agree completely that you connect the ground last as a precaution in case you hit something with the wrench when you are connecting the pos. terminal. What we were trying to figure out is why there would be less of a spark from the terminal itself when the order of the connecting is reversed. That does not seem like it would make a difference to me.

 

[glocklt4]

The reason why you connect the negative last is because,

Once the positive and negative are connected the battery is electrically connected to the engine of the boat. If you accidently hit something metal while wrenching the negative terminal down nothing happens. But if you hit metal while wrenching the positive down after the negative is connected the wrench becomes an "arc welder". This of coarse is much more prevalent under a car hood where everything metal is negatively charged when attached.

I agree with the last post, use some common sense and let the engine compartment door open for a while before working with the electrical system. If you smell gas you probably should take care of that problem first.

Yep, agree completely.

Just FYI, the "gas smell" i was referring to was any hint of gas at all, which is what i smell when first opening the hatch. Like mentioned, leaving it open to vent should be ok, but gas fumes do sink in the air since they are heavy, so there is still a possibility of them collecting at the bottom of the boat.

 

[Asureyez]

Its often said it's not the volts that kill you its the amps.

When working on battery terminals, turn off all the loads. Some loads you can't easily disconnect such as a bilge pump. However, it it's not running at the time will not cause batteries to arch.

Then, always evacuate the bilge of fumes, run the blower for 10 - 15 minutes, open all the ER hatches etc.

Second make sure both the post and the clamp are pristine bright and shinny clean. Oxidized connections increase resistance and promote heat and arching. Connect as a habit Pos first, Neg second.

Finally, be mindful of the surrounding metal objects that your wrench could strike while racheting the clamps closed. In really close quarters I cover possible contacts with rags or prop up cardboard shields over buss bars etc.

After batteries are installed, to prevent objects from possible contact with terminals. Always install terminal boots, and wire tie them securely over the clamp. Any loads with direct leads to the battery also need to be booted after installation.

Take particular care to make sure your batteries are secured to the deck. Strong clamp brackets held down with larger screws or bolts into good substrates. Spongy rotting wood battery platforms should be replaced with proper sized and coated plywood or better thick starboard.

Making sure you avoid arching possibilites in the ER, protect your boat from things vibrating loose. At least yearly, tighten all reachable terminal connections on busses and make sure quick connects are solidly connected. I like to keep mine wire tied together tight to avoid arching or worse corroded spade connectors.

 

[glocklt4]

Great advice, thanks asureyez

 

[sbw1]

There was a post here awhile back about a person who got a severe burn (second degree or worse?) when the wrench he was holding arced to his gold wedding ring. So, I would add, wear gloves or no jewelry when working on wires that might be hot.

 

[sprink56]

There was a post here awhile back about a person who got a severe burn (second degree or worse?) when the wrench he was holding arced to his gold wedding ring. So, I would add, wear gloves or no jewelry when working on wires that might be hot.

I was working on one of my "Hot Rods" years ago and somehow got my metal watch band accross the positive post of the battery and the radiator support. it burned the heck out of my left wrist...I still have the scar.

+1 on removing your jewelry. :thumbsup:

 

[osd9]

......always evacuate the bilge of fumes, run the blower for 10 - 15 minutes, open all the ER hatches etc. ...

How are you supposed to run the blower without a battery connected.....:grin:

 

[glocklt4]

I was working on one of my "Hot Rods" years ago and somehow got my metal watch band accross the positive post of the battery and the radiator support. it burned the heck out of my left wrist...I still have the scar.

+1 on removing your jewelry. :thumbsup:

Yikes! Glad I don't wear any jewelry!

 

[Asureyez]

How are you supposed to run the blower without a battery connected.....:grin:

Perhaps some smart aleck might run the blowers and then shut them off and work on the electric ... but probably not as its just too much fun to watch the fireworks!:smt021

 

[rondds]

Guys, I am no Edison or Franklin, but when connecting batteries on everything from my car to lawn tractor to boat, there is definitely LESS (if not NO) spark if you connect the positive first. I pull all 3 boat batts and my tractor battery every fall and put them in the basement. When I charge them up as spring approaches, I connect them to the charger in the same order and the spark is minimal. I just call 'em as I see 'em. Try it.

 

[mawyatt]

Guys technically the order of connection will not effect the spark magnitude, however connecting the + terminal first is the proper order for reasons mentioned. When disconnecting undo the - terminal first.