Proper Battery Etiquette

[rockfarmer]

I have heard it both ways, for years, and would like to ask on here. What is the safest way to connect/disconnect the battery on these tractors? ...or anything battery powered for that matter.

Connecting - Ground the battery first, then connect the hot wire? or Hot wire first, then ground?

Disconnecting - Remove ground wire from battery, only? or remove hot wire from battery, only? or remove both?

[Willy]

Proper? Beats me and I'd bet you'll hear plenty of ways to do it.

Me? Connecting: Hot then Ground
Disconnecting: Ground then Hot.

I don't mess with the hot if the ground is connected.

[Jim Becker]

I don't mess with the hot if the ground is connected.

Willy has your answer!

The order you do things won't matter if you are very careful and don't bump into anything with your wrench (or supply an electrical path through your body). But the safe way is to not put a wrench to the hot side with the ground connected. That is why almost all manufacturer instructions on any repair that gets near electrical components start with disconnecting the ground connection and end with reconnecting the ground.

[KC2LLW]

Ground first to make, last to break
Steve

[radioguy41]

Steve has it backwards: Ground - last to connect, first to disconnect.

[Dennis]

I like this question and I don't know why I did not include it on the safety test... or maybe I will

[Don McCombs]

Does the same rule apply to jumper cables, for the same reason?

[Crimson Tim]

Does the same rule apply to jumper cables, for the same reason?

Yes.

Also, the last connection is best made to a ground away from the battery, just in case there is a spark and there’s is any hydrogen hanging around the vicinity of the batteries. Some batteries can give off hydrogen when charging and perhaps at other times.

Good positive to bad positive
Then
Good negative to bad ground.

Where “good” is the vehicle/battery that is charged, and “bad” is the one that has insufficient charge.

This is, of course, assuming a negative-ground system. Reverse the polarities of that statement for positive-ground systems.

[47fivewindow]

If you put your wrench on the grounded side and hit the frame of the battery box nothing will happen. If you ground the other post (going to the starter) nothing will happen if the ground side has already been removed. If you start on the "hot" side first and touch the wrench to the frame bad things will happen.

[Willy]

If you put your wrench on the grounded side and hit the frame of the battery box nothing will happen. If you ground the other post (going to the starter) nothing will happen if the ground side has already been removed. If you start on the "hot" side first and touch the wrench to the frame bad things will happen.

I just hate that arcing and sparking stuff. The worst shock I ever got was back in my young n dumb days working on a 12v horn button in an '70s Chevy. I didn't disconnect the battery and that thing lit me up. Cheap lesson in "it's not the volts, but the amps".

[radioguy41]

Back in 1962 I was using a wrench to tighten the hot cable on a battery. I had my hand wrapped around the wrench so it wouldn't contact any metal but,,,, the wrench was against my wedding ring and the ring touched metal causing the gold ring to instantly get hot as blazes and burn my finger all the way around. Learned two things that day; disconnect the ground before fussing with the hot cable and also not to wear a ring when doing mechanical work. That was the 2nd time I was injured due to the ring but it was also the last.

[Lt.Mike]

Does the same rule apply to jumper cables, for the same reason?

Yes.

Also, the last connection is best made to a ground away from the battery, just in case there is a spark and there’s is any hydrogen hanging around the vicinity of the batteries. Some batteries can give off hydrogen when charging and perhaps at other times.

Good advice!
Years back I was charging my tractors battery which was parked a good distance from where I was working (so I thought ) in open air space. I’d say about 8’.
I set to put a cutoff wheel to a chain and all it took was one errand spark to shoot sideways towards the tractor and.... BOOM!!!
The battery turned to shrapnel and my ears were ringing. There’s nothing I can say to do justice to how loud that was. Everything had a film of acid on it including me.
Batteries are nothing to take lightly.

Mike

[Shane N.]

We were camping at a tractor show several years ago and a friend of mine was having golf cart trouble. It was electric and he's a very good mechanic and does it for a living. He was on one side of the cart and me on the other, both of us sitting on the ground. He was trying to clean a battery cable and I told him (just jokingly) don't short that cable out, he chuckled and said "I won't". 3 seconds later it sounded like a shotgun went off. He shorted it out and blew a battery up, only one of the 6 but we both had acid all over us. Luckily us or any of the other people around didn't get injured. He just simply wasn't paying attention and it only took a second.

[Lt.Mike]

Puts the Hindenburg disaster in prospective doesn’t it?
Hydrogen is some dangerous stuff.

[staninlowerAL]

Puts the Hindenburg disaster in prospective doesn’t it? Hydrogen is some dangerous stuff.

Agreed!! (The following comment has nothing to do with Rockfarmer's question but I think is interesting nonetheless.) OK, As long as the concentration is above the UEL or below the LEL but when it gets into that "range" in between those limits expect a KABOOM Figure this one out: some "floating roof" tanks in the petroleum industry are "padded" with flammable gas to reduce evaporation. This pad is kept above the UEL so as long as it stays there it's relatively safe. EDIT: I did not state the obvious fact that absence of an ignition source increases the safety factor (in all cases).