friend just told me something about wiring the second battery

[finkster]

do I need a fuse for the negative?

As already stated, no. But here's why.

For one, all the positives in your car are already fused. I'll get to that later. But for now keep reading.

Think of the chassis of your car as a big wire running from the negative post of your battery.

If anything positive touches ground prematurely, a HUGE burst of power travels through that wire until the wire melts and burns and no longer conducts electricity...At this point your car will be on fire. BTW have you ever wondered just how much power goes through a wire when it shorts?

Here's how you find out. Let's say I take a 2 foot piece of 1/0 and touch the positive and negative of the battery at the same time.

well, the resistance of the 1/0 for 2 feet is roughly .0000983 ohms. Now just a quick calculation.

12.5/.0000983=127,161 amps. Thats if the battery could put out that much....but it cant....

Lets say you have a nice new shiny Powermaster d3100 which can put out 1200 amps max....

12.5*1200=15,000 watts.

So thats 1200 amps and 15,000 watts coming through that wire only intended to carry 250 amps.

Anyways, back to fusing. The point of a fuse is to protect the wiring. How often is it that you accidentally touch ground with a POSITIVE wire? Happens a lot....if you read the situation above, it is a short....Now let me ask this...how often is it that you accidentally touch positive with a GROUND wire? Not very often. Actually if it ever happens you're a dipshit.

Here's the point. A ground wire under normal circumstances will never see that kind of power going through it, period. All the fuck ups usually occur on the positive end.

On another side note....think about it....when a wire shorts out....It is no longer positive or negative wire...its just a resistor which has super LOW resistance.

[MrSkippyJ]

As already stated, no. But here's why.

For one, all the positives in your car are already fused. I'll get to that later. But for now keep reading.

Think of the chassis of your car as a big wire running from the negative post of your battery.

If anything positive touches ground prematurely, a HUGE burst of power travels through that wire until the wire melts and burns and no longer conducts electricity...At this point your car will be on fire. BTW have you ever wondered just how much power goes through a wire when it shorts?

Here's how you find out. Let's say I take a 2 foot piece of 1/0 and touch the positive and negative of the battery at the same time.

well, the resistance of the 1/0 for 2 feet is roughly .0000983 ohms. Now just a quick calculation.

12.5/.0000983=127,161 amps. Thats if the battery could put out that much....but it cant....

Lets say you have a nice new shiny Powermaster d3100 which can put out 1200 amps max....

12.5*1200=15,000 watts.

So thats 1200 amps and 15,000 watts coming through that wire only intended to carry 250 amps.

Anyways, back to fusing. The point of a fuse is to protect the wiring. How often is it that you accidentally touch ground with a POSITIVE wire? Happens a lot....if you read the situation above, it is a short....Now let me ask this...how often is it that you accidentally touch positive with a GROUND wire? Not very often. Actually if it ever happens you're a dipshit.

Here's the point. A ground wire under normal circumstances will never see that kind of power going through it, period. All the fuck ups usually occur on the positive end.

On another side note....think about it....when a wire shorts out....It is no longer positive or negative wire...its just a resistor which has super LOW resistance.

a ground doesn't have that kind of power going through it? hmmmm

the reason you don't fuse a ground wire has nothing to do with accidentally touching wires together or which wire has more power going through it. You only have to fuse one side of a circuit, if one side fails, the circuit is incomplete and does nothing. Since the whole damn car (chassis) is the - side of the circuit, it is impossible to fuse that.

[finkster]

a ground doesn't have that kind of power going through it? hmmmm

the reason you don't fuse a ground wire has nothing to do with accidentally touching wires together or which wire has more power going through it. You only have to fuse one side of a circuit, if one side fails, the circuit is incomplete and does nothing. Since the whole damn car (chassis) is the - side of the circuit, it is impossible to fuse that.

Not unless you fuse the negative wire going from the battery to the chassis

And yea I'm aware that you only need to fuse one side of a circuit. Just think about convenience.

[Emoxihax]

convinced, ordered 2 more fuses. will have 2 positive fuses up at the first battery and 2 positive fuses next to the second battery

[Rose-Villian]

ABSOLUTELY NO NEED FOR FUSES ANYWHERE IN YOUR CAR AUDIO SYSTEM….. ADDS RESISTENCE, AND WASTE OF MONEY!

Been doing this for over 5 yrs and have never ever used fuses.... unless your shit is gonna ground out somwhere in your + lines then you should rethink where you run your power cables....

And SURELY no need for 4 damn fuses for one run of wire to the second batterys LMFAO!!!!

You know while your going fuse happy, fuse the + wires that run from your amp to your subs....

[7jezuz7]

ABSOLUTELY NO NEED FOR FUSES ANYWHERE IN YOUR CAR AUDIO SYSTEM….. ADDS RESISTENCE, AND WASTE OF MONEY!

THAT'S WHAT I WAS THINKING

/caps

I don't have fuses on my big three (had about 3 months now) either and if I added a second battery which I will soon, I'm not adding fuses either. If it goes up in smoke, oh well then there it goes. But if I do it right then no problem to be had.

[MrSkippyJ]

please use fuses.

[finkster]

ABSOLUTELY NO NEED FOR FUSES ANYWHERE IN YOUR CAR AUDIO SYSTEM….. ADDS RESISTENCE, AND WASTE OF MONEY!

Been doing this for over 5 yrs and have never ever used fuses.... unless your shit is gonna ground out somwhere in your + lines then you should rethink where you run your power cables....

And SURELY no need for 4 damn fuses for one run of wire to the second batterys LMFAO!!!!

You know while your going fuse happy, fuse the + wires that run from your amp to your subs....

Great advise, I guess because nothng has ever happened to you then nothing will ever happen. People never get into accidents or anything, right? Just because you take risks doesnt mean you should teach people to do things incorrectly.

douchebag.

[Paul M]

How does that saying go... Rather safe then sorry?

I don't have the money to go "Woops, to bad." if my system fried itself.

[finkster]

How does that saying go... Rather safe then sorry?

I don't have the money to go "Woops, to bad." if my system fried itself.

More like I dont have the money for a car b que right now.