WARNING!!! Automotive Battery Disconnect Switches
ฝัง
- เผยแพร่เมื่อ 23 ธ.ค. 2024
- WARNING!!! NEVER connect your automotive battery disconnect switch to the POSITIVE terminal of your battery. This is true for ALL top-post and side-post batteries*.
Why not?
#1 - They usually won't fit.
#2 - It's not safe. All battery disconnect switches add additional, exposed area to the terminal it is connected to. Whether it be a top-post or side-post disconnect switch. This additional surface area can more easily come in contact with other metal parts within the engine compartment. These other metal parts are usually negative grounded. And if the two connect, at the very least you will see a LOT of sparks. You might burn-up your battery cable, wiring harness, incur bodily injury, or ALL of the above.
(On negative-grounded vehicles. Most vehicles built after the mid-1950s are negative-grounded.)
For more information about automotive batteries, battery chargers, and battery float & storage chargers, visit: www.BatteryFloatChargers.com
I was wundering about this since I putting one of these on my truck that only gets used once every few months I remember in shop class our teacher saying any car with a ecu never disconnect the positive terminal and if you do negative comes off first great video saved me a headache down the road
You sir are a gentlemen and a scholar, and there are few of us left.
Chris Riner Thank you!
You are 100% correct about the danger of creating a short from positive battery terminal to chassis ground. However, the safest method is to isolate the positive terminal with the battery disconnect switch, and then properly insulate the battery disconnect switch itself.
In my youth, I once got a socket wrench across the positive 6 volt battery terminal and the rear seat frame of my 1956 Volkswagen. I can absolutely verify that a socket wrench will glow very red when shorted across a 6 Volt battery. The socket wrench welded itself to the seat frame and I had to kick it loose before the battery reached critical mass.
I've seen it too. Looked like the 4th of July under the hood.
The Erod1944 Channel
Heavy equipment (Euclid) from the 50s where positive ground, watched a guy short his wedding ring between post, wrench 1/4 inch steel battery cover. We were on an island in the Indian Ocean, they had to fly him to Thailand for treatment.
Real mechanics don't wear any sort of jewelry while working.
That was scary! And I would think much more intense due to being 6V.
Nor do real electricians. Your comment is probably more important than the video.
Thank you for posting this video, hopefully this saves people from injuring themselves! I have seen some Injuries from tools arcing across terminals mostly 24vdc and multiple batteries.
Finally someone posts a very useful warning! Good job!
Thank you!
when I was 17, while installing a battery and connecting the positive connection I accidentally hit the fender with the wrench (yes, i had connected the negative already - my bad). That sucker gave one spark and blew the lid right off the battery. It was wintertime, and i had on a hooded grey sweatshirt. I got a small cut between the eyes from flying plastic and turned the hood of the sweatshirt bleach white. I got an ambulance ride but fortunately had no acid burns to my eyes. Lesson learned. I am still appropriately overcautious around batteries now.
Did you see how close that guy came to melting his caliper (?) when showing the terminal diameters ?
A very dangerous demonstration as one who has seen a shorted battery explode will testify.
Are you "positive" about this??
Without sounding "negative", I'm "positive".
Yar!
These comments are positively polarizing - or is that negatively polarizing ? Oh, just do what he says.........
Very punny!
How much do dead batteries cost? Nothing. They're free of charge!
You are the MAN. hopefully all those "mechanics" are watching your videos thanks for your video.
Thanks for the compliment! I appreciate your feedback.
You're very welcome well done man.
Thanks for posting this. Caliper end was dangerously close. No mention that batteries can go BOOM from the explosive gasses?
thank you never done this and had no details of how to so thank you very much for your info. now i can go forge ahead
You confirmed what I suspected since the quick disconnect was apparently too small for the positive terminal of my top terminal battery. Thanks.
+Jerry Lester Glad to help!
By installing battery kill switch, will it affect the engine management system?
I have a battery drain that I cant find. I put one of these on my vehicle and the next day my vehicle battery was dead anyway. Anyone have any suggestions how I can create a kill switch that will work without removing both battery terminals every time I exit the vehicle? Thanks !
You talk about leaving tools on the battery, what about the micrometer you used to almost connect the positive and negative?
People in glass houses.........
In order to keep the caliper in frame when taking the video, I needed to position it as such. But, while doing so, I was VERY careful not to touch both terminals at once. Notice that I didn't set or leave the calipers on the battery after taking the measurements.
Watch This Shortly followed by leaving a spanner on top of the battery...........hmmmmm. Don't get me wrong I'm no safety nazi. I couldn't give a shit what other people do in the confines of their own workshops. If they want to lick battery terminals, naked, whilst splashing themselves in battery acid..............that is fine by me.
Yet I'm not going to tell them not to, just then to do exactly what I said others shouldn't do.
ZS6JMP I'm just putting out some safety tips. Nothing more. Some safety tips are common sense like, "Don't touch a hot stove". Some safety tips are not so common - and the reason I mention them. If people want to place tools on their battery and risk injury, smoke or make sparks near the flameable hydrogen gas coming out of their battery, pop the covers off their battery without safety glasses to block potential battery acid spray, or lick the terminals like you mentioned - I'm OK with that. My safety comment was addressed towards the viewers who were not aware of the potential hazard of touching both battery terminals at once with a metal tool, those who appreciate the tip, and for those who might be spared injury.
In order to keep the caliper in frame when taking the video, I needed to position it as such. But, while doing so, I was VERY careful not to touch both terminals at once. Notice that I didn't set or leave the calipers on the battery after taking the measurements.
In the end of this video you complain about 'so called mechanics' leaving their tools across the battery and how its dangerous and such. but at the 0:50 mark your dial calipers are about 1/2 away from hitting both posts
That's a guy. So I'm sure they nitpick their wife, and not husband.
No, it's a cat. See the photo?
Wow you almost shorted the battery with your caliper and you are wearing a ring!!! woops!
Sometimes when you're so focused on a task (like making this video) you inadvertently neglect safety. I know. I'm guilty.
You should be careful with your callipers. In this video they came very close to shorting your battery. Not a good example given your warning later with the ring spanner example.
I have an old Chevy Astro 89 I want to install a battery cut off switch to. I don't want a Frankenstein's power level and I dont want to have to open my hood to turn and twist a knob every time I'm ready to leave. I want to know if I can install an on and off switch, to the battery that mounts inside the car, I can flip to get the battery to make contact. There is some parasitic voltage leak that kills the battery within 1-2 weeks of non use and I cannot find where it's drawing from.
Very informative video. I learned something new today about battery disconnect switches.
Definitely reshoot the micrometer scene. I thought for sure we were going to see an explosion. Other than that GREAT INFORMATIVE VIDEO!
That's not a micrometer.
well, in SI measurement, micro- in front of any unit means 1/1000 th of the unit value. Since the display in the video has 3 digits to the right after the decimal point, then what would #John Dough call it then a 'milli-inch-meter?'.... Oh, that's too close a word to mm or milli-metre. How about Digital Internal and External vernier caliper linear ruler and sometimes pipe wrench?
@Barry Barry, you have not seen a high current arc!
even at 12 volts, a light weight device such as a Mechanics' scale, can cause sufficent current , that the device will weld itself to the contacts across the lead posts. When that happens, there is not much to do but get ready with a CO2 extinguisher, due to the heat built up in the cells, that eventually rupture. And if that is not enough , if sparks are created , and the atmosphere is the right amount of H2 plus air, you will get a big bang, as the Hydrogen 'burns' with the air and produces water vapour and CO2
See this for a battery bank that went boom!
www.cbc.ca/news/canada/small-fire-big-headache-for-bell-1.181523
Good Advice for the newbie and no-it-alls, you forgot to mention that the batteries have a bad habit of Exploding and really messing up everything including your life
Good point. I forgot to mention that.
Can i use a lawn amd garden 220 cca natteey to crank my 1500 beetle engine? I like its smaller than most batteries
This video has lots of negative and positive feedbacks.
Can you suggest a product to use a replacement? Need a way to shut down anything that is powered by the battery from the ignition to the lights when out and away from the car. (not an alarm system).
I'm not sure I fully understand your question but here goes...the knife-blade type of switch (shown in the video) would probably be your best choice. Of all the battery disconnect switches, the knife-blade type with its large copper surface area can handle the most amperage/current. If you want to keep the alarm system active while disconnecting power to all other devices in the car, just connect the power lead of the alarm directly to the battery. And connect the battery cable and any secondary leads to the battery disconnect post. This way the disconnect switch will not disconnect power to the alarm, but will disconnect everything else.
It all runs on smoke & once you let the smoke out, it doesn't work anymore. I always use a short extension on my ratchet when tightening the battery terminals to prevent doing just that. 3 cracked ribs from a battery box when I shorted out an 8D battery was enough of a learning curve!
I'm looking for quick connects that I can hook up a power inverter to my car battery. Do you have any recommendations?
The cable I've built from the battery to the inverter is 3 gauge.
The thicker the cable (the lower the gauge), the lower the resistance, the better you are. It all depends on the amperage draw of your power inverter at PEAK DRAW. You just need to get a disconnect that can handle the amperage draw of your power inverter. I would NOT use the knob-type ones in the video. The knife-blade type can handle more current but still might not be enough.
Thanks for the ideas you have contributed here.
Thanks YOU for your comment.
quick question,i just bough 2 T105RE 6 volt trojan golf cart batteries, hooked up in series for 12 volt system ,,,,first time i hooked them up to a 1.5 charger /maintainer they reached 13.6 before charge light turned green,,,,,,,a week later i hooked it up again but they reached 14.6 and still no green light,, i disconnected charger in fear of over charge,,,,,,,,,should i have allowed the charging process to continue to green light appeared ?........were the batteries attempting to equalize ?
+bob woerner I need more info. When you say that you connected to a "1.5" charger. Is that the amperage rating of the charger? When you say that the charging light "turned green". Some chargers lights glow green when they are charging a battery, some turn off the green light when the battery is fully charged. Which does your charger do? Regardless, some 12V chargers can not be used if connecting to (2) 6V batteries connected in series. Although the voltage is 12V (theoretically) the charger doesn't know the state of each battery independently. For example, let's say one of the 6V batteries is dead. But it's connected to a good 6V battery in series. All the charger sees is one battery that is 6V (the good battery) and will keep charging the 6V battery until is reaches 12V (which it will never get to without being connected to another good 6V battery.) So, the charger will never turn off and will over-charge the good 6V battery. To be sure however, I would contact the charger manufacturer for more info. on your particular charger.
Excellent - I am about to fit a 'Projecta" switch - BUT the salesman insisted it goes onto the Positive terminal. I queried this and pointed to the package saying "Suits negative battery post". He then said - oh well I suppose either post will isolate. I will speak to him..... However I do wish Projecta had made their instructions more forcefully by saying do NOT connect to positive.
Thanks for posting this! i just ordered one! lol
I still do not understand why is this difference between ways to break the circuit. Positive, negative.... just break it, and it's all the same, or not?
"Electrically" it doesn't matter. But I would have hoped that my video would have explained why breaking the NEGATIVE side is preferable.
That doesn't sound like a good enough reason to risk shorting out the terminals with any tool? Worse case scenarion the spanner or other tool would weld itself to the terminals and youd have to stand back and watch it burn itself out because getting hold of a red hot metal tool is NOT my idea of how to lose my fingers burning them to a crisp attempting to save a battery or tool. I wouldn't fancy cleaning up the mess afterwards either.
by god I'll make it fit!
Thanks for this. I had no idea.
I'm expecting no answer for this but a buddy of mine has a riding lawn mower that keeps draining the battery.
Is a 12 volt toggle switch an option for killing a battery. I just don't know how a 4 or 6 or 8 gauge wire could mount to 2 tiny prongs and not burn up or something go wrong even on the Ground Side of the Battery.
Much appreciate this video.
Thanks for the great video!
Good video, thanks.
Awesome POST
I have a kill switch on my car that worked great on my positive terminal. Then all of a sudden one morning I turn the key to start it the switch keeps wanting to turn off all the power to the car. It doesn't stop doing this. What might this be?
Do you have one of those "knob-type" switches, like the one with the green knob in my video? If so, I'm almost positive that the problem is dirty or corroded contacts on the switch. It's not that the switch is turning off, it's that there is too much current trying to pass through the dirty switch resulting in blocked current flow. In other words, there's a lot of resistance in that switch, when there shouldn't be any resistance when the switch is "On". Clean the contacts thoroughly. If the contacts are too corroded, replace the switch.
No it's actually has a small little lever and a button that turns off the power. Kinda like a mini breaker.
If it's a circuit breaker, then it appears that the load (the amount of current) going through the breaker is too large for the breaker to handle so it "trips" and disconnect power. If it's an auto-reset breaker, after the breaker cools down, it will re-set and your connection is made once again. Wish I could see a picture of it, or post a link to what you have.
Makes sense, yes the load is probably too much for it to handle. When it "trips" it cuts all power from the battery. Until I reset it manually by pushing the lever.
OK. So now you can either go with a larger amperage circuit breaker to avoid it prematurely tripping, or reduce the load on that breaker. CAUTION! If you go with a larger circuit breaker, and it's too large, you will burn your wiring harness (and maybe your vehicle) before the breaker trips!!! I can't/won't advise on what size breaker to go with since I don't know your situation.
That's what hammers and beer can metal is for.
I have a slow drain that is draining the battery over a course of a couple days. If I use the QD on the negative it'll still drain as there's a slow drain still due to the positive cable being hooked up making a circuit. I've got to disconnect the positive in order to break the connection. Thoughts?
You need to have BOTH the positive & negative cables connected in order for a parasitic drain (like a clock, radio display, computer, under-hood light that won't shut off, short circuit, etc) to prematurely drain the battery. If you disconnect EITHER the positive cable, OR the negative cable, OR both cables, you have eliminated ANY chance of a parasitic device draining your battery. In other words, you've broken the circuit. So, you do not need to disconnect both cables with a QD.
If you have a QD placed on the negative cable, and the QD is in the off position, and your battery is still prematurely "draining", this means that your battery needs to be replaced as it is probably shorting internally. Is it a fillable battery or maintenance-free? If you can fill it, have you checked the water level?
Warranted the battery out today. Should have been the problem
Something wrong in Denmark. If any one side of battery cable disconnected no amp draw can happen as you need both sides connected at battery to have an amp or voltage draw. Someone told you shit
Nice video. A lot of useful information.
Thanks I did not know ,glad I watched
He kind of left out the main reason for a negative disconnect. All manufacturers and maintenance/repair manuals instruct you to disconnect the negative terminal before doing...whatever it is your going to do....
Good point. Thanks for the additional information.
I found this information to be shocking.
Very punny. Thanks for your POSITIVE comment.
Hahahaha!!! I loved it!!!
My generic group 35 battery has equal sized post and my switch sits on the positive side and nothing has happen but i have done all the above including a metal bar touching the battery to the chassie for some amazing sparking action lol.
very help full!!!!
Very nicely done.
I am confused - The April 14, 2014 post says "WARNING!!! NEVER connect your automotive battery disconnect switch to the POSITIVE terminal of your battery." One month ago you "Watch This" wrote "But I would have hoped that my video would have explained why breaking the POSITIVE side is preferable." ???
Good catch. Typo on my part. I should have stated that breaking the NEGATIVE side is preferable. Sorry about that. I just corrected my comment of April 14th.
I just wanted to see sparks
There's another reason why a switch is more practical on the negative terminal: The positive corrodes far quicker, which can be prevented by covering both terminal & cable with acid free vaseline.
If the switch is placed on the positive terminal, you pretty much end up greasing the entire assembly...
There's no need to grease up the negative terminal.
Good tip
why are you talking so robotic I think you have watched 1 to many 50's and 60's videos lol
It was one of my first videos and I'm not a paid actor.
A like for you and wishing you a great weekend too.
Thank you
You're welcome!
SUPER INFORMATIVE AND NECESSARY VIDEO..THANK YOU
Thank you. Much appreciated!
Who the hell puts tools on top of the battery?
probably everyone - once
I do and who gives a fuck anyway
Blackie Chong u obviously gave a fuck :)
TheFlwildman Funny....and probably true!
F
A friend once decided to short the terminals on a 12 v battery to see if it was fully charged/ functional. It welded the screwdriver to the terminals and then the battery exploded destroying the building.
great info
is this guy for real wow
You will disconnect power from your car's ECM and it will lose its settings no matter which terminal you disconnect.
Thank you, I know now how to do it right.
well then just install the fucking thing on the negative post problems solved
You tricks good
Who the hell has got so much room in their battery compartment for all these dumb disconnect switches anyway?
And around batteries use insulated tools and or have a insulating cap and cover on one terminal!
Great advice thank you! :)
At 3:15 a warning is given about tools on battery and I agree that's bad that's why I'm all for laws that increase safety, will you help me pass a law that has everyone in a car wear a motorcycle helmet as well as reinforced caging inside the cab...thank you ....
Were you dropped on your head as a baby? Is that why you want everyone to wear helmets?
+RiRoProductions Being facetious? I'm sick of 12 pages of warnings telling me how my cell phone can kill me. They are dangerous. They too often make reading the actual instructions disjointed, unuseable.
RiRoProductions you do realize that wearing a helmet with an airbag is even more dangerous though right??
gracias but you messed it up with the second advice. duhhhh
DON'T tell me what to do
why am i here is this not common sense. Rule #1 if you don't know what you are doing leave it alone .. just joking we all learn my our mistakes
Thanks for the tips safety sam ( sarcasm)
remember power go's from neg to pos that is why you always take off the neg wire, look in you auto books read !!!!
Why put a disconnect on a vehicle unless it is for off road use? Buy a cheap tool set and just pull the cables off! And there are POSITIVE disconnects they are designed in a different manner and do not connect directly at the battery post.
If the disconnect does not connect to a battery post, then it can be used for either a positive or negative disconnect. After all, they're all just an on-off switch. However, the switches that are designed to connect DIRECTLY to a battery are designed (as noted in the video) to be used as a negative disconnect only.
Should have made that point in the video.
im guilty of the tools on the battery.. yikes..